Passive House Plus (Sustainable building) issue 42 UK

INSULATION | AIRTIGHTNESS | BUILDING SCIENCE | VENTILATION | GREEN MATERIALS

S U S TA I N A B L E B U I L D I N G

GOING SWIMMINGLY

Exeter opens UK’s first passive leisure centre

decarbonisation plans Flat pack on track

Unlocking scalable ecological timber builds

Ed Begley Jr

Hollywood star on 50 years of eco activism

Issue 42 £5.95 UK EDITION

ROMAN PAST, PASSIVE FUTURE City of York shows visionary

EDITOR’S LETTER

PASSIVE HOUSE+

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EDITOR’S LETTER

PASSIVE HOUSE+

Publishers Temple Media Ltd PO Box 9688, Blackrock, Co. Dublin, Ireland t +353 (0)1 210 7513 | t +353 (0)1 210 7512 e info@passivehouseplus.ie www.passivehouseplus.co.uk

Editor

Jeff Colley jeff@passivehouseplus.ie

Deputy Editor

Lenny Antonelli lenny@passivehouseplus.ie

Reporter

John Hearne john@passivehouseplus.ie

Reporter

Kate de Selincourt kate@passivehouseplus.ie

Reporter

John Cradden cradden@passivehouseplus.ie

Reader Response / IT

Dudley Colley dudley@passivehouseplus.ie

Accounts

Oisin Hart oisin@passivehouseplus.ie

Art Director

Lauren Colley lauren@passivehouseplus.ie

Design

Aoife O’Hara aoife@evekudesign.com | evekudesign.com

Contributors

Ed Begley Junior actor and environmental activist Toby Cambray Greengauge Building Energy Consultants Joe Lyth Respond Architects Marc Riain doctor of architecture Sofie Pelsmakers architect Peter Rickaby energy & sustainability consultant David W Smith journalist

Print

GPS Colour Graphics www.gpscolour.co.uk | +44 (0) 28 9070 2020

editor’s letter W

e are living in extraordinary times. But the language we use to explain this moment in history is not fit for purpose. Climate change is far too insipid and neutral a term for what is happening to the world.

Climate crisis is better, climate emergency is better still, but both terms suffers a fatal flaw, in that that our experience of crises and emergencies is that of temporary events, where decisive action can pull us back from the precipice. As James Vaccaro of the Climate Safe Lending Network put it in an article pitched at financial regulators, we need to be talking in terms of climate collapse.

The situation we face is not like the global financial crisis, from which the markets ultimately recovered, even if that recovery baked-in residual suffering for the many while pushing wealth into the hands of the few. Nor is it an emergency from which we can be saved through the ingenuity and bravery of medics and firefighters. It is a collapse. And what’s more the collapse is unavoidable, to some extent. The delay between belching emissions into the atmosphere and impact on climate means that even if the people of the world collectively downed tools today, ditched their cars, disconnected their heat and electricity supply and stopped eating, the world would still get hotter, and the weather would still become more extreme.

Faced with the inevitability of further deterioration in climate, we must start to adapt in earnest. This is not to say that we should abandon our efforts to reduce emissions. Nothing could be further from the truth, and the thought of echoing the kinds of sequences of arguments peddled by fossil fuel shills makes me feel physically ill. It goes a little like this: The climate isn’t changing. Actually it might be changing, but it has always changed, and we’re not adding to it. Okay, maybe we’re adding to it,

ISSUE 42 but it’s too expensive to do anything about it. It’s too late – let’s just focus on adapting.

We must commit fully to adaptation, but we must also increase our resolve to dramatically cut emissions, reduce our voracious appetite for precious, finite resources and snap out of our indifference to the destruction of the ecosystems which support the existence of life on earth. The mind boggles as to what kind of response could address such a demanding ask, but mercifully, in the context of the built environment, we already know a lot of the answers. Avoid building if possible, and retrofit first. If we must build, don’t make it too big, make it adaptable, and try to put it where we can potter about on foot, bicycles or public transport. Build it out of the most environmentally benign materials possible, in a manner designed to withstand all kinds of craziness in terms of changes to weather and microclimate. And build it to proven high performance standards like passive house, to minimise energy use and reliance on energy infrastructure that may struggle to keep up.

We also have adaptation of another kind to do at Passive House Plus – adapting to the departure of our deputy editor Lenny Antonelli, who has been a valued colleague and friend for the last 14 years. We had been going six years when Lenny joined us, immediately enriching the magazine with his rare ability to write in a scientifically literate yet extremely readable manner.

I will greatly miss his counsel and our ruminations on the minutiae of sustainable building, but he has left an indelible impact on this magazine, and the rest of us at Passive House Plus will be watching his future success with pride.

Regards, The editor

Cover

Render of Ordnance Lane passive house development, York Mikhail Riches / Darc Studio

Publisher’s circulation statement: Passive House Plus (UK edition) has a print run of 9,000 copies, posted to architects, clients, contractors & engineers. This includes the members of the Passivhaus Trust, the AECB & the Green Register of Construction Professionals, as well as thousands of key specifiers involved in current & forthcoming sustainable building projects.

Disclaimer: The opinions expressed in Passive House Plus are those of the authors and do not necessarily reflect the views of the publishers.

About Passive House Plus is an official partner magazine of The Association for Environment Conscious Building, The International Passive House Assocation and The Passivhaus Trust.

ph+ | editor’s letter | 3

CONTENTS

PASSIVE HOUSE+

CONTENTS COVER STORY

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FINAL SAY: REFLECTIONS ON LEAVING PASSIVE HOUSE PLUS

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21

After fourteen years working on Passive House Plus and its predecessor, our departing deputy editor Lenny Antonelli muses on how our understanding of sustainable building has changed over the years – and on what may come next.

8

18

BIG PICTURE In the first installment of a brand new photo essay feature, in which we profile passive houses and other eco-buildings from around the world, architect Joe Lyth writes about how the aesthetic of simple backcountry cabins inspired the design of his rural home on New Zealand’s North Island.

NEWS AECB conference to showcase timber innovation, world’s first passive house hospital completed in Frankfurt, and the Passivhaus Trust publish new passive house & embodied carbon resources.

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COMMENT In the latest missive in his series on the history of low energy design, Dr Marc Ó Riain looks to some wacky and wonderful experimentation in a project that aimed to transform public perception of Milton Keynes; Dr Peter Rickaby says that doing retrofit well and at scale remains an enormous technical and financial challenge; and co-authors of the new book Designing for the Climate Emergency - A Guide for Architecture Students shed some light on the thinking behind the new guide.

CASE STUDIES

26

From Nero to zero

Local authority housing takes a giant leap forward in York The historic Roman city of York is embarking on an ambitious programme to redefine council housing for the 21st century, building 450 mixed-tenure passive houses across eight sites in the city, and unashamedly prioritising walking and cycling, and shared outdoor green spaces, over cars. It may seem too good to be true, but a cityscape whose architecture still so manifestly displays its extraordinary history is now pointing to the future of urban design.

PASSIVE HOUSE+

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CONTENTS

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INSIGHT

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Going swimmingly

Devon complex is set to be UK’s first passive certified leisure centre The environmental journalist George Monbiot has written about how we need an era of ‘public luxury’ and ‘private sufficiency’ — as opposed to private luxury for the few — to mitigate overconsumption and climate breakdown. And it’s hard to think of a better example of public luxury than this superb new leisure centre in Exeter, which consumes just a fraction of the energy of typical facilities, and is set to be certified to a bespoke version of the passive house standard.

Block buster

Galway passive house births low carbon concrete blocks With emphasis in sustainable building shifting towards reducing embodied carbon, an obvious question comes into focus: is this an existential threat to the concrete industry? One passive house in Claregalway shows that – with a little help from Passive House Plus – concrete product manufacturers can make meaningful moves in the right direction.

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Breath of life

Enerphit upgrade rejuvenates Rathgar redbrick The skilful deep retrofit of a red-brick semi on the south side of Dublin has brought an old property into the 21st century in terms of energy performance and living space, while carefully upgrading its century-old façade with breathable materials.

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Flat pack on track

Partnership promises scalable ecological timber builds What do you get if you cross a quantum physicist, a forensic accountant, a merchant, an engineer and a software-whizz-kid architect?

A terrible punchline presumably. But as Jeff Colley discovered on a trip to Sussex, you get something not to be laughed at: a collaborative approach that may be about to unlock a scalable, highly sustainable, circular economyproof, flat pack build approach.

Hollywood star on 50 years of eco activism

Actor Ed Begley Junior is one of America’s bestknown and longest-standing environmental activists. Fresh from lighting up our screens in the final season of Better Call Saul, Begley spoke to Passive House Plus about the roots of his activism, and what drives him on in the face of such adversity.

MARKETPLACE Keep up with the latest developments from some of the leading companies in sustainable building, including new product innovations, project updates and more.

Is it okay to retrofit heat pumps before building fabric?

How flexible can heat pumps be to handle what may be inexactly defined heating demands, asks Toby Cambray?

ph+ || contents contents || 55 ph+

Harris Academy School Sutton the first Passivhaus secondary in the UK. The 2020 winner of Education Estates’ Architect of the Year, CIBSE Project of the Year.

Harris Academy School Sutton the first Passivhaus secondary in the UK. The 2020 winner of Education Architype Awards: Estates’ Architect the Year, Architect CIBSE Project ofYear the Year.

Education Estates’ of Education of the 2020 CIBSE Building Performance Winner 2020 Architype Awards: AJ100 Sustainable Practice of the Year 2015, 2016 and 2019 Education Estates’ Education Architect of the Year 2020 CIBSE Building Performance Winner 2020 AJ100 Sustainable Practice of the Year 2015, 2016 and 2019

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COLUMN

LENNY ANTONELLI

Final say: Reflections on leaving Passive House Plus After fourteen years working on Passive House Plus and its predecessor, our departing deputy editor Lenny Antonelli muses on how our understanding of sustainable building has changed over the years – and on what may come next.

O

ne of my earliest assignments for Construct Ireland magazine, the predecessor to Passive House Plus, was to visit two certified passive houses in rural County Carlow. This was back in 2008, when the magazine’s understanding of what ‘sustainable building’ meant was still evolving.

The two houses had little aesthetic merit, but they were only the second and third certified passive houses in Ireland. Back then the German standard seemed strange and exotic, and while the houses were plain looking, they also felt like the future.

Four years later the magazine felt confident that yes, this was the future, and we rebranded as Passive House Plus and launched a UK edition. At the time, there was plenty of debate in eco-building circles over the merits of passive house — about whether it was too onerous, too architecturally stifling, too airtight and too reliant on mechanical ventilation. But in hindsight it certainly feels like passive house won the day.

Super-insulation, airtightness, the elimina-

work of those who push for better building standards each day.

But it does make me wonder what the next vanguard will be. In a recent issue of this magazine, Peter Rickaby argued that retrofit should not just be about energy and carbon, but that it must also create beautiful places to live. And I wonder if we need to make more space on the cutting edge of sustainable building not just for left-brained concepts like building physics and heat loss, but right-brained ones like beauty, community, and equality.

Obviously, these are not new design concepts, but it sometimes feels that the mathsbased world of passive house and the woollier realm of architectural ‘placemaking’ exist in different galaxies. It’s heartening to see projects like the passive house schemes in York that are profiled in this issue, which is also my last as deputy editor of the magazine. The York schemes aim to dramatically cut energy and carbon, but also to foster community, and create beautiful places to live.

Last year, my fiancée and I moved from

New ownership models like cohousing can help us move beyond the false dichotomy of massive debt or insecure tenure, but they need support. tion of thermal bridging, and mechanical ventilation are increasingly accepted as integral to good building, even when it’s not a passive house being built. The regulations inch closer to embracing these concepts too, albeit faster in Ireland than the UK. Developers might argue that passive house is too difficult or expensive, but it’s rare to hear anyone say that it isn’t better.

Over the last few years, the leading edge of green building has turned its attention to measuring embodied carbon, a much more subjective task than measuring heat loss or airtightness. But embodied carbon is now, thankfully, creeping its way towards the regulatory agenda too.

Of course, all of this is happening far too slowly given the dangerous warming of the planet, and I don’t mean to make this progress sound inevitable: it is only down to the hard

Galway City to Cloughjordan Ecovillage, an intentional community adjacent to a small town in the Irish midlands. The houses in the ecovillage, which are all of natural materials, were built between 2008 and 2013. Heat is provided by wood-chip district heating, walking and cycling is prioritised over cars, food is grown on the community farm and allotments, and there is ample space for nature in the woodlands, orchards and grassland.

But more than that, it has been a revelation to live in a place where social encounters and gatherings and neighbourliness are designed into the fabric of the community. And where people have literally built their own homes, often with little previous experience.

It is also obvious to me that a community with its own farm and heating network, and its pool of skills and resources, will be more resilient as climate breakdown begins to dis-

rupt our lives more and more. It’s measurably better for the planet too: a 2015 study found that a resident of Cloughjordan Ecovillage has an ecological footprint of 2.03 global hectares, far lower than the Irish average of 5.3 (but still above the 1.6 that the Global Footprint Network says is available to everyone).

There’s also something powerful in a community taking charge of providing for its own housing needs. Earlier in the summer, the Cloughjordan Cohousing group hosted an event called ‘Housing Ourselves’, which heard from different Irish groups trying to get community-led housing projects off the ground, such as Nimble Spaces in Kilkenny and Common Ground in Wicklow.

It was inspiring to hear from those seeking to sidestep the failure of the state and take the provision of affordable housing into their own hands. But it was also frustrating to see how these groups have sometimes struggled within a system geared more towards developers than communities.

I attended not just as a journalist, but also as someone who, at 36, does not own his own home and now wishes to put down roots in a community without taking on an absurd level of debt. Affordability is an overlooked aspect of sustainability: it is hard to live sustainably and modestly, to choose the bicycle over the car, to buy directly from local farmers, and to share skills and resources, when we are wracked with debt and overworked. New ownership models like cohousing can help us to move beyond the false dichotomy of massive debt (a mortgage) or insecure tenure (renting), but they need support (see Self Organised Architecture’s roadmap for community-led housing in Ireland at www.soa.ie).

Over my years with the magazine, editor Jeff Colley and I often joked about the irony of writing about beautiful, architect-designed passive houses while having little prospect of living in one, with our journalists’ salaries.

That prospect seems further away than ever given Ireland’s housing crisis, but I am hopeful that the failure of our top-down housing model can spur the growth of a more equitable one that blossoms from the bottom up.

A fully referenced version of this article is online at www.passivehouseplus.ie

ph+ | lenny antonelli column | 7

NEW ZEALAND

BIG PICTURE

BIG PICTURE PASSI VE & ECO BUIL D S F R O M A R O U N D TH E WO R LD In the first installment of a brand new photo essay feature, in which we profile passive houses and other eco-buildings from around the world, architect Joe Lyth writes about how the aesthetic of simple backcountry cabins inspired the design of his rural home on New Zealand’s North Island.

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BIG PICTURE

NEW ZEALAND

1. Envelope first The project came about as a result of our kids getting sick in our standard, too-cold-or-too-hot, mouldy New Zealand house, and my wife Sarah and I being unable to watch any longer. We decided to put our (minimal) money where our mouths were, to prove that high performing, healthy homes can be achieved at standard budgets, while still being beautiful places to live.

Cost was the key constraint. As first-time buyers with a small deposit, prioritising and compromising were essential. An envelope-first strategy was decided on to prioritise performance: site specific insulation, good airtightness, great windows and doors, no thermal bridging. We would develop the interior as a family once we moved in. What resulted is an unpretentious, passive house certified home that blends into its rural context, while keeping its inhabitants warm, dry and healthy year-round.

The initial design was a single-storey home that could be extended into the roof space later. But to get funding from the bank, however, we ended up having to build the first-floor bedroom and bathroom to increase the value of the house to match the build cost, but without running up the construction cost – a challenging exercise and negotiation with the contractor!

ph+ | new zealand big picture | 9

NEW ZEALAND

BIG PICTURE

2. Of its place Our search for a plot of land took us about 45 minutes north of Auckland, where we found a site barely within our budget.

The northwest facing saddle here has expansive views of the Makarau River valley, and the surrounding area consists of weathered rural infrastructure, traditional villas, and a growing number of new homes, all embedded into a mixture of pasture, pine wood and native bush.

The exposed site is both baked by the sun and battered by rain and winds, so the proposal had to respond to a range of environmental factors to ensure durability, performance, and habitability.

The design developed with the location and took precedence from both its rural context, and our love of the simple robustness of backcountry huts. Lower Saddle sits comfortably into its surroundings like it was always there – belying the high-performance nature of the project. The response included careful orientation to the view, the sun and the prevailing wind, with thoughtful positioning of openings, north and western overhangs, and exterior shading.

3. High performance Lego Cost and performance were our priorities, and to minimise thermal bridging and embodied carbon, steel and concrete were out. Due to the sloping site a suspended timber floor on piles with sheep’s wool insulation was chosen over a carbon-hungry concrete slab, and structural insulated panels (SIPs) were selected for their thermal and airtight qualities, with prefabrication reducing waste and construction time.

The panels were cut to shape in the factory from the building information model (BIM). They arrived on site all numbered, and went together like a Lego set. The walls took a couple of days to install, then the mid floor and gables, before the roof went on in a day and a half. The project achieved a final blower door test result of 0.375 air changes per hour, so the passive house airtightness target (0.6) was more than achieved.

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BIG PICTURE

NEW ZEALAND

4. Wider environment

5. Interior environment

As well as being energy efficient, we aimed to minimise the project’s impact on other resources. Large rainwater tanks and efficient sanitaryware ensure ongoing water resilience, and all sewage and sanitary waste is treated on site, in turn watering and fertilizing a growing orchard. A solar hook-up is included, and we plan to install PV in the medium term when we have the budget.

The site was open pasture when we purchased it, and is slowly being developed based on permaculture principles, with some areas being replanted with native trees, some left to re-wild, and the rest being developed into food production and a food forest to feed us, and hopefully eventually, the wider community.

All buildings need adequate ventilation to ensure good indoor air quality, but opening windows, which is relied on in NZ, only works some of the time. Mechanical ventilation works all the time, with openable windows for additional user comfort and control.

We installed a ducted mechanical ventilation system with heat recovery from Stiebel Eltron in the good-sized laundry. In the full height mezzanine I designed in a bulkhead down the spine of the building to accommodate the ducting, and to make it easier and more cost effective to install. We have been monitoring the interior with Tether environment sensors and the system has performed perfectly, with the interior almost always between 18-24C with no active heating or cooling, constant levels of humidity, and very low CO2 readings.

Finished photos: Dan Scott | Construction photos: Joe Lyth

ph+ | new zealand big picture | 11

NEW ZEALAND

BIG PICTURE

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To keep costs in check the design utilises a simple, compact form and efficient design of spaces to reduce the building footprint, simplify the construction, and mitigate the volume of materials. Every inch of space inside works hard, and the covered decks to the north and west provide further living space outside.

Visual connections between the rooms create a feeling of space with a double height living space and overlooking mezzanine, and high-level windows and ‘arrow slot’ openings into the upstairs rooms - they remind me of medieval castles, where a little window high in the wall of a banqueting hall would often be the most intriguing part.

12 | passivehouseplus.co.uk | issue 42

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BIG PICTURE

NEW ZEALAND

8. Materials with character Painted plywood cladding and metal roofing were selected externally, with a scoria red finish reminiscent of tramping huts and embodying the local rural vernacular. Internally the SIPs were painted as opposed to lining them, reducing trades and cost. Plywood linings were selected for interior walls — lower carbon than plasterboard, and easier for sanding off children’s drawings.

We made the plywood kitchen, cast concrete sink and counter, and copper splashbacks ourselves, all materials that gradually gain a patina and character over time. Native Totara from a friend’s farm further north was milled into trims and skirtings. The plywood grain and textured SIPs that form the spaces are broken up by brightly painted doors, each a different colour to add splashes of joy.

9. Part of the family We moved in at the end of May 2021 before the exterior was finished, and a couple of weeks before the hot water heat pump system was installed. (The house has no space heating system beyond a small panel heater, which we’ve turned on for an hour or two all year.

We’re looking into electrical underfloor heating eventually, but we barely need it.) Since then, we’ve been developing, dressing and finishing the house together as we learn how it functions for us.

Moving into a ‘shell’ has given us the chance to experiment – I’m installing Woodtex panels between beams in the downstairs bedrooms for sound attenuation, and for texture. To keep costs down the finishing of the plywood was left to us, so we’re slowly filling, sanding and varnishing the interior walls. The house is truly growing with us.

ph+ | new zealand big picture | 13

NEW ZEALAND

BIG PICTURE

10. For the future New Zealand has some of the lowest performing, unhealthiest, yet most expensive housing in the world. Lower Saddle shows that this doesn’t have to be the case — all Kiwis can have healthy, affordable homes with low operating costs, and a light impact on the planet. The project balanced priorities with what could be added or upgraded later – a kitchen is easier to upgrade than your windows and walls, for example.

In following an envelope first approach, the high-performance home provides a healthy enclosure, with an interior that can be developed alongside our growing family, delivered on a budget lower than most minimum code homes. Materials and construction methodology reduced the amount of embodied carbon and construction waste through prefabrication, setting out of materials to mitigate waste and minimise cost, and ongoing reuse of offcuts and materials in the project.

11. Performs as designed Since we moved in the house has absolutely ‘performed as designed’ with energy bills of $100-$130/month for everything (around 40 per cent lower than a standard NZ home, which would usually also include gas too), while maintaining comfortable temperatures year-round with no active heating or cooling, and the children’s respiratory issues have disappeared.

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NEW ZEALAND

The next generation of heat pumps: The new Vitocal 150-A With a flow temperature of up to 70°C, the new Vitocal 150-A is ideal for retrofits.

It achieves its high efficiency by using R290 (propane) refrigerant, which is particularly environmentally friendly with an ultra low global warming potential of 0.02 (GWP).

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The compact design saves up to 60 percent of the space required and reduces installation time by up to 90 minutes, compared to conventional heat pumps.

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ph+ | new zealand big picture | 15

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NEW ZEALAND

BIG PICTURE

12. A learning resource Since completion we have been able to grow into the home, but also use it to help educate others (thanks to Sarah’s incredible patience!). It’s been part of the international passive house open days, and the Superhome Movement tours, and will be again this year; I’ve used it as a vehicle to explain building performance in presentations to universities and product suppliers, and it’s fantastic to be able to invite clients up to show them what a passive house looks, feels and sounds like.

As a model for other homes in NZ applied at scale, this would provide a warm, dry, healthy and affordable home for all New Zealanders, with minimal ongoing maintenance and operational costs; and as our home, we couldn’t be happier.

Joe is a registered architect and certified passive house designer at Respond Architects in Takapuna. Originally from North Yorkshire in the UK, Joe studied and worked in London from early 2007 before making the move to New Zealand in 2016 with his wife Sarah, and has since welcomed three little Kiwis into the world. He is especially passionate about high performance and healthy buildings, and finished his own passive house certified home on a tight budget in May 2021, to show healthier, affordable buildings are possible for everyone in New Zealand.

Embodied Carbon Excellence The project has achieved excellent embodied carbon results, based on analysis

by Elrond Burrell of Via Architecture, performed using PHribbon. It blitzed the RIBA 2030 Climate Challenge target for embodied carbon of 625 kg of CO2 equivalent per square metre, scoring a miniscule 120 kg CO2e/m2, and achieved an A+ for upfront carbon and A++ for embodied carbon on the LETI scale. The house is below the BRANZ detached house (embodied and operational) carbon budget for a 2C warming limit.

How did the house achieve such low figures? A combination of factors con-

16 | passivehouseplus.co.uk | issue 42

tributed, including the lack of concrete for foundations or superstructure, and the lack of rendered block or brick cladding, and the lack of a heating system.

One other key factor played a part: the timber used for the structure was covered by an Environmental Product Declaration (EPD) from the Wood Processors and Manufacturers Association, which included New Zealand-specific figures for the end of life of timber. Because the timber was assumed to be landfilled upon the building’s eventual deconstruction and – unlike the RICS methodology in the UK – the majority of the timber is as-

sumed not to biodegrade as methane – a substantial amount of CO2 sequestered in the timber is assumed to remain sequestered. This hints at an inconvenient truth about life cycle assessment: if that timber had been assumed to be salvaged and reused in the future, the sequestered CO2 would have passed outside of the boundary conditions of this building’s life cycle assessment and onto the next use – giving the same embodied CO2 result as if the timber had been incinerated. Had that been the case, the building would still have achieved a superlative score of 238 kg CO2e/m2.

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NEWS

PASSIVE HOUSE+

NEWS AECB conference to showcase timber innovation

Rendering: Bond Bryan Architects

T

he AECB conference 2022 will focus on practical solutions to decarbonising buildings, with a particular emphasis on timber-based approaches with the potential to deliver low energy, healthy buildings at scale while minimising the use of precious resources and impact on the environment.

With live demonstrations front and centre to the event on 30 September, particular emphasis will be placed on the role of innovative uses of timber and bio-based materials, with a focus on giving delegates a detailed understanding of a number of carefully chosen assemblies. The event will also give delegates exclusive access to information on a new AECB retrofit standard for delivering retrofit where significant building fabric interventions may not be viable.

The venue for the event is a significant point of interest in its own right: the brand new mass timber-built Centre for Advanced Timber Technology (CATT) at the New Model Institute for Technology and Engineering (NMITE) in Hereford, which delegates will be invited to tour.

The event will focus on a demonstration area showcasing a number of assemblies for new build and retrofit, including assemblies developed by AECB experts, and proprietary assemblies from AECB partners. These assemblies will then remain at CATT for at least six months to inform and educate visitors including industry professionals and students, via a number of events and courses Breakout sessions will see delegates splitting into groups to participate in workshops demonstrating how each assembly is

18 | passivehouseplus.co.uk | issue 42

constructed, to give delegates a detailed understanding of practical best practice examples – and provide the opportunity for networking and focus group-style feedback to manufacturers and component suppliers.

The AECB is partnering with a number of carefully selected suppliers in the industry to sponsor the event, help build the AECB assemblies and provide proprietary assemblies. Confirmed sponsors include some of the leading suppliers of high performance, low environmental impact building products on the UK market. Platinum sponsors include Partel, Ecological Building Systems, and a joint sponsorship from Steico and Ecomerchant, along with gold sponsor Green Building Store.

Partel are providing a number of products for an AECB deep retrofit and extension assembly, which will also include a window provided by Green Building Store. Ecological Building Systems are providing products for an AECB lighter retrofit assembly, to showcase appropriate solutions for harder to treat buildings. Woodfibre insulation and I-joist supplier Steico are teaming up with specialist distributor Ecomerchant to build assemblies showcasing the use of timber and timber-based products.

The event will kick off with an introductory talk from CATT director Prof Robert Hairstans, followed by plenary talks from AECB CEO Andy Simmonds and Passive House Plus editor Jeff Colley, which will outline the thinking behind this year’s conference, and how those thought processes manifested themselves in the

assemblies on display. The event will then call on AECB experts Beth Williams of Build Collective and Toby Cambray of Greengauge to discuss the assemblies from a structural engineering and building physics perspective, while PHribbon author Tim Martel will discuss the implications of each assembly in embodied carbon terms.

Delegates will then break out into discussion groups for each assembly, aided by technical experts from product suppliers and AECB experts.

Building on a new partnership between the AECB and the Centre for Advanced Timber Technology, the assemblies at the conference will remain in situ at CATT for six months as education displays, with quarterly reviews thereafter. The assemblies will be utilised by CATT as part of the Timber TED (Technical Engineering & Design) 1 and Timber TED 2 courses to run at NMITE, in conjunction with Edinburgh Napier and Timber Development UK, from September 2022 to April 2023. After this, the assemblies will feature in a proposed BSc in Sustainable Built Environment from Sept 2023, as well as in CPD events CATT plans to run in partnership with a range of industry bodies over time.

From September to December, CATT will also be displaying the Department of Education’s (DfE) GenZero prototype classroom, formed from UK homegrown timber – which will also be on display during the AECB Conference. The DfE plans to run a series of workshops to a range of different organisations, and to people ranging from school children to civil servants. The DfE also aim to launch their energy pod concept at CATT in the 1st quarter of 2023. •

(above) The Centre for Advanced Timber Technology at NMITE, Hereford under construction. The brand new mass timber-built sustainable building hub will host the AECB Conference on 30 September.

PASSIVE HOUSE+

NEWS

World’s first passive house hospital completed in Frankfurt

T

he world’s first passive house hospital has been certified by the Passive House Institute – showing that the standard can be applied to even to the most demanding building types.

The energy performance specifications for the new 700-bed hospital, Klinikum Frankfurt Höchst, were developed following a baseline study by the Passive House Institute commissioned by the state government of Hesse.

Due to their intensive 24-hour operation, hospitals are one of the most energy use intensive building types, as a large number of technical devices are used in emergency rooms, operating theatres and intensive care units, as well as in the patients’ rooms.

In a hospital, the electricity consumption is generally three to four times higher than in a residential building. The baseline study showed that the equipment can have a major influence on energy demand. Energy efficient devices were specified – not only because they use less energy, but because they reduce cooling demand too.

"This precisely is why the energy-efficient concept is particularly worthwhile for hospitals,” said Passive House Institute joint managing director Dr Jürgen Schnieders.

"This applies for efficiency measures for the building itself as well as for energy-efficient technical devices. ” The institute was closely involved in the planning and construction phases of the new building.

The high energy efficiency of the building makes it possible to achieve the higher room temperatures required in patients’ rooms with less energy use. Fresh air is supplied by the ventilation system, which saves energy via heat recovery. The baseline study showed that despite the higher room temperature and ventilation air change rate required, the space heating demand could be limited to the passive house target of 15 kWh/m² using coordi-

nated measures.

The new hospital building provides more than 660 beds for patients and another 40 beds in an outpatient clinic, in addition to eleven operating theatres. Over 1,600 employees will be working in the new building.

In order to assist with more hospital projects – including new builds and refurbishments – the Passive House Institute has made the baseline study on the implementation of the passive house standard in hospitals available free of charge. •

(above, l-r) Passive House Institute joint MD Dr Jürgen Schnieders, Hesse minister of economic affairs Tarek Al-Wazir and city councillor Rosemarie Heilig present the passive house certificate to management board chairman Martin Menger.

Tackle cost-of-living crisis with rapid fossil fuel detox & retrofit revolution C limate solutions charity Ashden’s response to the announcement of BP’s quarterly profits of £6.9bn is that the excessive profits of BP and all the oil super majors must be re-directed by government into low cost, low carbon energy efficiency measures and green energy alternatives.

BP announced its highest record quarterly profit in 14 years while at the same time typical household energy bills have been forecast to hit more than £3,600 a year this winter – and £5,000 a year next year.

Responding to the profit announcement Harriet Lamb, CEO of Ashden, said: “BP is the latest in a run of oil super majors declaring unthinkable bonanza profits.

Lamb said the profit levels were unsound, unethical and economically disastrous for the country as a whole. “They underline why our dependence on fossil fuel giants must be ended,” she said, pointing out that fossil fuel companies are benefiting from record-breaking profits while ordinary people face record-breaking and

life-destroying energy bills.

“When the average bill is likely to increase by over £3,600, a £400 discount won’t even touch the sides of people’s bank accounts,” she said. “In less than three months, a typical energy bill will cost a third of the state pension. But where is the government’s plan? We need a rapid detox from fossil fuels.”

Lamb called for a double-pronged strategy by government to take a stand against such massive profiteering and enforce a much bolder windfall tax than was implemented in May. She said the tax should re-direct excess profits into emergency funding for scaling up domestic energy efficiency measures, and train of workers to undertake a UK-wide retrofit revolution in order for people to be less dependent on fossil fuels.

“If this action is not taken, the government will be guilty of a dereliction of duty,” said Lamb. “It has a duty of care to support citizens to have decent and afford-

able living conditions. Allowing the fossil fuel companies to enjoy such profits knowing that it will push people into crisis, is plain wrong.”

Ashden, which works with organisations and local authorities on progressing green skills for retrofit, is calling for speedy and focused government support on energy efficiency and domestic decarbonisation measures such as insulation and non-fossil fuel domestic energy solutions such as solar energy and ground source heat pumps, so that people can use less energy in their homes, reduce their bills, while helping the nation meet its legally binding carbon reduction targets.

Ashden is part of the Warm This Winter campaign – a coalition of UK fuel poverty and environmental organisations calling for immediate government action and preparation plans to deal with the energy crisis. •

ph+ | news | 19

NEWS

PASSIVE HOUSE+

New passive house & embodied carbon resources Do thicker insulated walls, triple glazed windows, & MVHR ventilation systems tip the scales unfavourably for passive house when it comes to embodied carbon?

T

he Passivhaus Trust (PHT) has published resources exploring the role of passive house design in reducing whole life carbon emissions from buildings. The resources include a freely available position paper and primer, alongside an on-demand webinar, and draw on recent research that counters the argument that designing to decrease operational carbon emissions increases embodied carbon emissions due to additional materials.

The paper outlines the relationship between passive house and embodied carbon, addressing common misconceptions. It says: “Passivhaus buildings are optimised for net zero, providing the best route to minimise whole life carbon. Outstanding levels of building performance minimise operational carbon, while the passivhaus design methodology encourages optimisation of embodied carbon through efficient use of materials and radically reducing the heat and cooling plant.”

Comparing a house built to UK building regulations with the passive house standard, measured over 60 years, modelling shows that, even with additional building elements, the passive house has a lower initial embodied carbon and less operational carbon over

20 | passivehouseplus.co.uk | issue 42

its lifetime, leading to a smaller whole life carbon footprint.

By championing compact and rationalised design, improving the form factor of buildings and simplifying details, passive house buildings result in less material use, the modelling concluded. Building to the passive house standard also avoids the need for a later retrofit to meet more demanding standards.

Passive house quality assurance and use of higher quality materials contribute towards reducing embodied carbon through improved resource efficiency. Quality passive house components can offer longer product lifespans and a reduced need for repair and maintenance.

There are also substantial savings made in retrofitting existing buildings, compared with the high embodied energy costs of demolition and rebuilding. As an example, St. Sophia’s Primary School in East Ayrshire revealed that 40 per cent embodied carbon savings were made just by undertaking an Enerphit retrofit rather than rebuilding the school.

The passive house community is increasingly acknowledging and focusing on the issue of embodied carbon and material choices, demonstrated by the development

of several carbon counting tools. The AECB PHribbon plug-in for PHPP makes whole life carbon calculations quick to perform using the material quantities already embedded in a PHPP assessment.

According to Passivhaus Trust policy and research director Sarah Lewis: “The relationship between embodied and operational carbon is rapidly changing. As buildings become more energy-efficient and heating is electrified, embodied carbon is a significantly larger slice of a smaller whole life carbon pie.”

Lewis added that efforts to tackle embodied carbon must not come at the expense of energy efficiency. “Continuing to reduce energy demand is still important as it reduces peak loads and shrinking our collective winter energy demand will reduce the level of future zero carbon energy infrastructure and storage needed,” she said. “Reducing operational and embodied carbon is not an either/or choice.

We must aim to tackle both simultaneously.”

For more information on the Passivhaus Trust’s resources on embodied carbon and passive house visit: https://bit.ly/PHTEmbodiedCarbon

COLUMN

DR MARC Ó RIAIN

HomeWorld 1981: car engine-driven houses & low energy ideas that stuck In the latest missive in his series on the history of low energy design, Dr Marc Ó'Riain looks to some wacky and wonderful experimentation in a project that aimed to transform public perception of Milton Keynes.

A

s the UK labour government led

by James Callaghan handed over to Margaret Thatcher’s Conservatives in May 1979, focus on public supplied housing would switch dramatically to private supply.

Nowhere would this be more evident than in the last of the ‘new towns’ in the suburbs of London, Milton Keynes.

As people tried to escape the congestion of London city, towns were being planned and formed around new ideas. Milton Keynes was founded on a bronze age site northwest of London which included the famed Bletchley Park, code breaker central during WW2 and the location of Alan Turing’s Enigma cracking machine. So new ideas and innovation were not novel to Milton Keynes.

In the late 1970s the town was in danger of becoming a social housing ghetto, so the local council decided to try to attract private developers to build private housing. Inspired by precedents like Letchworth Garden City in 1905, a model town developed to entice city dwellers to the countryside, Milton Keynes Development Corporation decided to create a new exemplar zone to attract people to the town with energy efficient housing. They set up a private housing unit to build a series of exemplars from multiple developers, who were eager to establish a foothold in the developing town.

The Milton Keynes Development Corporation decided that new energy efficient private housing would shift the public perception of the area and segue nicely to new Conservative policies of privatisation. It organised the construction of fifty-two houses for public exhibition, drawn from the best and most innovative designs from all over the world.

The often wacky and innovative new forms were packed with modern technologies and new building methods that we take for granted today. The various designs featured heat recovery ventilation systems, heat pumps, heat exchangers, solar panels, south-oriented double glazing, passive solar gain, winter gardens, thermal mass, super‐insulated timber frames, and kit houses from New Zealand for example (Byrne 2011).

The buildings varied from very tradi-

tional Tudor style semi-Ds to, pyramids, mono-pitches, full A-Frames, prairie style bungalows, Saskatchewan inspired glass and brick houses, and treehouse inspired turreted houses. The variety was staggering, with thirty-two variations in total, each developed by a different sponsor.

One such project was ‘Future Home 2000’ designed by John Doggart and featured on BBC’s The Money Programme in 1981.

The BBC referred to those who designed the houses as ‘energy conscious designers.’ The Future Home was essentially two super-insulated houses set in an L-shape and connected by a glazed conservatory which utilised thermal mass to bank solar gain.

The house was fully prefabricated off site and brought to site in component form for assembly. It had a high degree of insulation in the timber frame walls (externally clad with brick), featured gold coated double glazing and solar water panels.

It “has a large conservatory which faces south. This is heated by the sun, and small fans distribute the heat into the main house.

The house is designed so that all major rooms face south and is very well insulated to about twice the current (1981) building regulation standards. It has double glazed windows with a special coating which lets in light but gives the equivalent thermal benefit of triple glazing, and is also draught sealed. Doors are foam filled to improve their insulation, and have special magnetic fridge type draught sealing. The conservatory also serves to support a small solar system for heating domestic hot water, made by Pilkington Solar Products.

Unlike normal solar heaters, it needs no separate store, pump or electronic controller, so is cheaper and maintenance free. The appliances in the house were chosen for their low energy use, for instance, the lights use only a quarter of the energy for the same amount of light as a normal bulb” (Fuller, S.; Doggart, J. and Everett, R. 1982).

There were separate heating systems; coal and a specially adapted Fiat car engine that ran on gas driving an electric generator with heat recovery that made it 90 per cent efficient. The whole house could be centrally

(above) Showcased in Homeworld ’81, Future Home 2000 included a number of experimental approaches including an adapted car engine to run an electric generator with heat recovery.

controlled using a Honeywell digital meter.

The overall efficiency of the building was 60 per cent better than a contemporary equivalent. The house also featured a home office and an electric vehicle… 41 years ago!

The HomeWorld exhibition was a thorough success attracting 140,000 visitors in one month, attracting private developers to Milton Keynes, and reframing the town with a forward-looking development council. However, the designers who had hoped that developers would grasp the innovations on show with new tech housing, were disappointed by industry uptake. Moreover, as oil prices fell through to 1985, the projected payback periods for energy saving measures rose.

HomeWorld 1981 would be followed up in 1985 with Energy World which would go on to define a number of methods we use today like Building Energy Ratings.

For anyone interested in this topic there is a good documentary, Homeworld ‘81: 40 years on, available at vimeo.com/540791219 n A fully referenced version of this article is online at www.passivehouseplus.ie Dr Marc Ó Riain is a lecturer in the Department of Architecture at Munster Technological University (MTU). He has a PhD in zero energy retrofit and has delivered both residential and commercial NZEB retrofits In Ireland. He is a director of RUA Architects and has a passion for the environment both built and natural.

ph+ | dr marc Ó riain column | 21

DR PETER RICKABY

COLUMN

Bad retrofit is worse than no retrofit But doing retrofit well and at scale remains an enormous technical and financial challenge, writes Dr Peter Rickaby.

R

ecently, I have been inspecting housing areas across the UK. Frequently, I have visited them in person, walking the streets with landlords, going into homes and talking to residents. I have toured other areas using Google Street View and landlords’ databases. My aim has been to understand how we might retrofit homes and bring them to zero carbon. This exercise has been dispiriting: it has revealed how challenging it is to scale up retrofit, both technically and financially.

The cost of improving the whole UK stock by 2050 is eye-watering – for social housing it is often tens or hundreds of millions of pounds beyond the resources at landlords’ disposal. And hanging over the problem is the current increase in fuel poverty, and the knowledge that fuel poor households are not interested in reducing emissions – they just want to be warm.

My travels have reminded me of a lesson learned long ago, and have provided two new lessons. The reminder is of what we learned from the failure at Fishwick, in Preston: bad retrofit is worse than no retrofit. At Fishwick, nine years on from their bungled external wall insulation (EWI) programme, most residents are still living in damp, mouldy, unsaleable homes, waiting for remediation and redress.

Similar cases have occurred in North Wales, South Wales, Hull and Middlesborough, and I suspect that there are more. These are cases that triggered the Each Home Counts review and drove the subsequent establishment of the BSI Retrofit Standards Framework and the development of the PAS 2035 specification for whole-house retrofit. They emphasise that we cannot afford to let our retrofit technical standards and good practice processes slip or be eroded.

On one large, city-centre estate in the north-east of England, about half of the early twentieth-century two-storey terraced houses were insulated with EWI ten years ago, by a previous and no doubt well-meaning landlord. The original houses are elegant, with bay windows, stone cills and lintels, and attractive brick details. The insulated houses are ugly and unpleasant – the elegant architecture has been covered up, poor detailing has resulted

22 | passivehouseplus.co.uk | issue 42

in water staining and mould on the render, and the interiors are damp and mouldy because of thermal bridging combined with under-heating and under-ventilation. There is even one street where the houses on one side have been insulated and exhibit all these problems, while the unimproved houses on the other side remain architecturally beautiful and dry, albeit cold. Residents must wonder why the EWI was installed, how it has come out so badly, and why we are even considering doing more of it.

The time for demonstration and pilot projects has passed.

The first new lesson is that the usual approaches to retrofit — external wall insulation, internal wall insulation (IWI), underfloor insulation (UFI), air source heat pumps (ASHPs) etc., are often impractical or inappropriate, or difficult to implement. My colleagues and I have catalogued the circumstances that make EWI difficult or impossible: the dwelling is listed or in a conservation area, or subject to an Article 4 prohibition; or the architectural quality is high; or the front elevation abuts the public pavement, leaving no space for EWI; or there are side alleys or passageways that are too narrow to insulate; or there are no eaves overhangs to protect the top of the EWI; or the walls are festooned with services whose relocation will be too costly and take too long; or there are simply too many leasehold properties the omission of which would be unsightly and inappropriate. Similarly, if we consider IWI, what do we do if the kitchens and bathrooms have just been replaced, or have ten years of remaining life? Sometimes the rooms are too small (especially bathrooms, kitchens, hallways and stairways) and vapour-permeable IWI would be too thick. UFI is rarely affordable when the home is occupied, unless we opt for spray foam insulation applied by robot. Ser-

ried ranks of ASHPs on high-density terraced housing or medium-rise blocks are unlikely to be acceptable visually, or because of the noise they make; often there is nowhere that isn’t intrusive to put them.

There are other examples, and we have workarounds, including hybrid insulation (EWI combined with IWI) and communal ground source heat pumps (GSHPs) serving streets and blocks, but they all add to the cost and complexity of the retrofit challenge. Some of them require integration with landlords’ asset management and investment strategies, so that retrofit is part of broader improvement plans and work can be properly programmed or proceed when properties are empty. Other options such as communal GSHPs require large capital investment, local disruption and serious engineering.

The second and equally important lesson is that the time for demonstration and pilot projects has passed. We have been piloting retrofit for twenty-five years. Now we have a climate emergency: to achieve zero carbon we have to deliver five retrofitted dwellings per minute, for the next twenty-eight years.

We know how to do retrofit well, to manage risks and minimise unintended consequences: that knowledge is coded into the Retrofit for the Future report, the Enerphit standard, the AECB retrofit standards, PAS 2035, the LETI Climate Emergency Retrofit Guide, the Construction Leadership Council’s National Retrofit Strategy and other documents. With the exception of some largescale GSHP installations, we don’t need any more pilots — they are just an excuse for not rolling up our sleeves, getting our heads down and delivering domestic retrofit at scale. n

Dr Peter Rickaby is an energy and sustainability consultant working on retrofit projects with Savills social housing team. He also chairs the BSI Retrofit Standards Task Group, and is an Honorary Senior Research Fellow at UCL, where he helps to run the UK Centre for Moisture in Buildings (UKCMB).

The views expressed here are his own, and do not necessarily reflect the views of Savills, BSI or the UKCMB.

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C L I M AT E E M E R G E N C Y

COLUMN

Why we wrote Designing for the Climate Emergency Over the last century architects have unwittingly played a key role in terms of climate collapse and a slew of linked catastrophic environmental and social harms. But as the new book 'Designing for the Climate Emergency - A Guide for Architecture Students' explains, architects can help humanity step back from the void by integrating evidence-based sustainability approaches throughout their work. Co-authors Sofie Pelsmakers, Elizabeth Donovan and Aidan Hoggard shed some light on the thinking behind the new guide.

D

esigning for the Climate Emergency took us over two years to write. In Climate change is not distant. we It is underway.

We are that time, saw the pandemic hit each in the midst of a climate emergency. Architects can country records broken – and must be – part of theand radicalclimate-related change needed, and we must understand the impact of local in different parts of the world: the hottest decisions on the global scale. temperatures recorded, This book guides you as an architecture student tothe longest heatwaves, create truly sustainable designs, reflecting the urgent the worst wildfires, extreme droughts in some need for action. It tackles the quadruple challenges of the climate emergency: parts and floods in others. We heard the Adapting to a changing climate • mitigation Intergovernmental Panel on Climate Change • Climate change • Creating a positive and restorative design issue a Code climate justice locally and globally. Red: a severe warning • Improving(IPCC) Focussing onthat holisticclimate design approaches through 10 change is not distant. It is real, key themes, it will help you integrate into your design and it already happening.

We are in a projects consistently highis values from all areas of sustainable architecture. climate emergency.

Structured around the different stages of the design urgency and scale of the transformaprocess throughThe five illustrated chapters, it highlights what you need to consider when developing a project tion that is needed is unprecedented. This is and when to think about it. Reflecting what is required by years of study, it outlines what a year 1we or year 3 because globally, have been burning fossil student should be aiming for. This provides step-bystep guidance, preparing you for practice. fuels such asarchitecture coal, oil and natural gas at an Unique features include: key recommendation incredible rate and scale. With every degree checklists, measurements against the UN Sustainable globalcasetemperatures rise (it is already Developmentthat Goals, readings, studies, student examples, notes and an extensive glossary.

1.1C globally, and we’re trying to limit that Become inspired and more confident to build to 1.5C), we risk unhinging ecosystems a sustainablerise tomorrow. further, leading to more extreme events and increased loss of lives, livelihoods, homes and cities, and devastation to the natural world. That is why each country is shifting towards a zero carbon or carbon neutral society. Because built environment processes are responsible for around 36 per cent of the CO2 emissions alone, carbon neutrality can only be achieved if we also stop using fossil fuels for the construction and operation of the buildings we design, and transform and start using the available resources we have responsibly on a global scale.

And it is not just CO2 that matters: every minute of the day, we use resources that can never again be replenished and that create waste, destroy natural and human habitats, and pollute the air, water and soil we rely on, jeopardising human life and wellbeing, and other species. Design choices we make at our ‘drawing boards’ affect people and communities thousands of miles away. For example, we import cheaper materials from regions halfway across the world and ignore the environmental and human costs of doing so.

Despite this awareness, almost every architecture project continues to contribute to the current climate crisis, embodied injustices and ecological breakdowns worldwide. Our ISBN 978-1-85946-964-4

9 781859

469644

24 | passivehouseplus.co.uk | issue 42

26/01/22 12:27

Almost every architecture project contributes to the climate crisis, embodied injustices and ecological breakdowns worldwide. architectural responses need to be drastically altered. Every single project needs to not only minimise but reverse these damaging processes immediately and create a positive and restorative impact – this is an essential part of a climate emergency design approach.

To do this, we must make an urgent shift in the values we hold, and a shift in how and why we do things. This is what our new publication aims for.

Our book, which is targeted at architecture students (which arguably includes each of us as teachers and practitioners too), aims to tackle the quadruple challenges of the climate emergency:

1. Ensuring climate change mitigation (ensuring our actions don’t exacerbate the crisis further), 2. Adapting to a changing climate (even if we stop burning fossil fuels today, we cannot escape the effects of a changing climate put in motion more than one hundred years ago), 3. Creating positive and restorative designs (restoring prior damages inflicted), 4. Improving climate justice locally and globally (no longer exploiting others – human, non-humans and nature).

COLUMN

(above) Figure 1. The ten climate emergency themes in which high standards must be achieved (left image): future and global responsibility, infrastructure, environment, passive resilience, energy and CO2, materials, health and wellbeing, people and community, delight, and performance. The middle diagram indicates that to achieve holistic sustainable architecture, certain sustainability aspects cannot be prioritised (large red petals), at the expense of reduced standards elsewhere (the red dotted lines with smaller red petals). Instead, all aspects must meet high standards, even when some themes are prioritise.

At the core of the book are ten climate emergency themes (see Figure 1), which are mapped against the UNSDGs and RIBA 2030 Sustainable Outcomes metrics, of which energy and CO2 is one theme. But our book goes beyond energy and CO2 solutions, ensuring that consistently high values in all areas of sustainable architecture are integrated into projects as part of a holistic approach to dealing with the climate emergency (see Figure 1). Often as architects we claim that our projects are sustainable, but they have rarely been holistically sustainable, tackling only certain aspects and neglecting others. By the end of studies, a student should be fluent in applying all themes in their design projects, as this is what is also necessary in practice.

While the book provides a wealth of information, it does not focus on simply providing more knowledge and more information. Instead, it focuses on the right questions that students should be asking and when; what information they need, and the

actions and decisions they need to take at these different stages of the design process. To help students do this, there are around thirty key recommendation checklists to use throughout the design process and related to different climate emergency themes; a selection of two hundred listed case studies; a glossary and key notes to further explain the text. There are also around two hundred images, half of which illustrate student approaches from the UK, Denmark and Finland.

The book aims to instil sustainable values that go beyond the visible and calculable impacts of our own design decisions, and bring into focus the architects’ future and global responsibility. The future and global responsibility theme covers climate and social justice issues. The book also questions whether we should build at all, putting circular construction principles at its core (e.g., retrofit, adaptability, designing for disassembly) as well as future-proofing for a changing climate.

In architectural education it is important to emphasise that designing sustainable architecture and zero carbon buildings means little if this is only achieved on paper and if these standards are not met in reality, once the spaces are handed over to the users. As such, in the performance theme, we recommend that students create a ‘performance risk plan’ as part of their project to map out the project’s ‘risk areas’ (see Figure 2). By ‘performance’ we also do not simply refer to energy and CO2 (i.e., related to building and systems performance) but also to users’ well-being, satisfac-

(below) Figure 2. Example of a ‘performance risk plan,’ which can be used as a template for understanding and reflecting on the potential risks within a project.

Potential identified risk unknown wind speeds

Implications unclear if wind energy as proposed will be feasible

How likely is it to occur? (likely, unlikely) likely; wind speeds in urban areas are often not high enough to make wind energy feasible

Solution try to measure windspeed on site for a short duration; propose alternative renewable energy; have back up plan, and plan for both

Implemented strategy alternative strategy proposed

C L I M AT E E M E R G E N C Y

tion, and spatial and material performance.

Our design decisions should be based on knowledge and the best available evidence, with foundations of how to achieve this provided in chapter one. However, we cannot claim our proposed designs are sustainable without evaluating if this is the case. While we cannot know for certain whether our designs work until they are built and used, we can do our best at the design stage to ‘test’ and ‘validate’ our designs. Validation means testing and checking if our project meets the sustainability goals we set in earlier design processes. In our book we focus on how students can set these goals early on, and a whole chapter is dedicated to validation and communication of these goals and approaches throughout the design process, illustrated with student examples.

Other themes also aim to shift the role of the architect and the role of architecture towards co-creating with others, and centring the needs of people and communities (including non-humans and nature, rather than centring ourselves or for recognition in outdated architecture awards. This is not to say that architectural contributions should not be delightful (delight is one of our ten core themes), but it is focused on the user and their experience.

As architects, we are co-creators and custodians of the built environment. We can – and must – be part of the radical change needed, and we must understand the impact of local decisions on the global scale. There is no room for error. Instead of seeing this as alarmist or an attack on our creative pursuits, it requires determination, conviction and optimism to trust that we are part of the solution, not the problem. And it requires us to reframe what architecture is, with more, not less, creative thinking. Our book is both a call to action for students and teachers to urgently reframe our values and culture as well as a tool to help achieve it. n Designing for the Climate Emergency - A Guide for Architecture Students, published

by RIBA Publishing, is out now. Authors: Sofie Pelsmakers, Elizabeth Donovan, Aidan Hoggard & Urszula Kosminska

ph+ | climate emergency column | 25

YORK

CASE STUDY

IN BRIEF Scheme: 450 passive houses across eight sites in York; mixed tenure Method: Timber frame Location: York, England Standard: Passive house classic targeted

26 | passivehouseplus.co.uk | issue 42

CASE STUDY

YORK

FROM NERO TO ZERO LOCAL AUTHORITY HOUSING TAKES A GIANT LEAP FORWARD IN YORK The historic Roman city of York is embarking on an ambitious programme to redefine council housing for the 21st century, building 450 mixed-tenure passive houses across eight sites in the city, and unashamedly prioritising walking and cycling, and shared outdoor green spaces, over cars. It may seem too good to be true, but a cityscape whose architecture still so manifestly displays its extraordinary history is now pointing to the future of urban design.

By David W Smith

ph+ | york case study | 27

YORK

CASE STUDY

We are passionate about creating communities with mixed demographics.

C

ity of York Council has embarked on arguably the most ambitious passive house scheme so far conceived by any local government in the UK. The council is building 600 energy efficient homes across about eight sites near the centre of the city, and 450 of them will not only be passive houses, but also net zero carbon for operational energy. What’s more, York have hired Stirling Prize winning architects Mikhail Riches to design the schemes.

These radical developments are nothing less than a re-imagining of how society can best function in the 21st century. Everything has been done to make the mixed-tenure developments accessible to all social classes and age groups. Car use is discouraged; every home has a bike shed and private open space; green communal areas run between the homes and around the sides.

The schemes have taken inspiration from Joseph Rowntree, the York chocolatier who built the model village of New Earswick

28 | passivehouseplus.co.uk | issue 42

on the outskirts of York at the start of the 20th century. In New Earswick, the arts and crafts houses lie along streets lined with grass verges. Two fruit trees have been planted in every garden and the homes are flooded with light. In an egalitarian manner, there are houses for both workers and managers.

But whereas Rowntree was concerned with presenting an alternative to the city’s slums and deprivation, an effort has been made to adapt his ideas for the modern age, says Michael Jones, York’s head of housing delivery and asset management.

“Joseph Rowntree was a great inspiration.

We directly borrowed from his ideas, such as planting trees for every home, designing homes so that they are filled with natural light and having front doors that open onto green spaces rather than roads. Like Rowntree, we have made the developments as inclusive as possible so people can live there regardless of job and income. Our goal is to tackle modern-day social ills, which are very different to what they were in 1902,” he says.

One reason behind Jones’ desire to develop passive houses for York was his experience in charge of an ambitious 500-home development for the Joseph Rowntree Trust in 2016-2017. Derwenthorpe was also a mixed-tenure scheme, with open spaces, self-sustaining communities and low carbon goals. But the homes were not passive houses and sometimes didn’t live up to their ambitions in terms of energy performance.

“It too was very ambitious. We thought about health, wellbeing and communities that support each other, reducing reliance

on the state and private car ownership. But there were performance gaps, some of the homes were not as warm as expected, or residents felt draughts. What drew me to passive house is you get what you pay for. The testing and certification process provides a lot of confidence for the client team.”

But the council’s 600-home scheme, Jones is keen to emphasise, is not just about achieving the passive house mark. “I would never criticise anyone for doing passive houses. But you could live in a passive house with a large driveway and three cars.

Our developments are about supporting a sustainable lifestyle in all of its facets — sustainable transport, being well connected and minimising the need to travel, as well as the houses being very energy efficient, and having the renewable technology to generate power on top of that.”

City of York Council began its 600-home project in 2017. At the time, the council owned several vacant sites and was facing an ongoing affordability crisis, with demand for housing outstripping supply. House prices are relatively high for the north of England.

When adjusted for income, properties are similarly expensive to parts of the southeast. The first 88 homes on the first site, a 165-home project at Lowfield Green, have already been occupied and the rest will be completed by late 2022. They were designed

by BDP’s Sheffield office and are mixed tenure, with 40 per cent social rent and shared ownership allocations, and 60 per cent private housing sold under the Shape Homes York brand. But with the next stage of development, York wanted to go much further

CASE STUDY

and build zero carbon passive houses.

Fifty architectural practices submitted bids and Mikhail Riches was appointed a week before winning the 2019 Stirling Prize for the ground-breaking Goldsmith Street, a certified passive social housing scheme in Norwich which featured in issue 32 of Passive House Plus. “I wasn’t familiar with the practice before their submission, but we visited Goldsmith Street and thought it was fantastic,” said Jones. “When they won the Stirling Prize, it gave us a lot of confidence we were right to take the next step on from Lowfield and build passive houses, incorporating PVs, air source heat pumps and renewables that take it to zero carbon.”

When David Mikhail, co-founder of Mikhail Riches, saw York’s advertisement in the Architects’ Journal he found the brief “really refreshing”. He says: “It was the first time I’ve seen a call for our services that suggested the client thought as we do and used the same language. It’s rare you get asked questions that – because you absolutely know your stuff – you’re desperate to answer. Rather than the usual mind-numbingly tedious brief, York were asking questions like ‘how would you go about making places suitable for pedestrians and cyclists rather than cars?’ and ‘how would you make a really great place to raise a family?’ It was aspirational design. So, they got it right from the beginning. And that was before the new councillors came into power a short

The schemes have taken inspiration from Joseph Rowntree, the York chocolatier who built the model village of New Earswick.

time later and became even more ambitious, targeting zero carbon. I don’t know another council targeting both zero carbon and delivering such high-quality homes.”

The DNA of the York developments, Mikhail says, is similar to the Norwich passive houses. In Norwich, there are shared children’s play areas at the heart of the communities and a similar idea is being developed for York on a bigger scale. Mikhail says: “But in Norwich they were just ginnels, slightly enhanced alleyways, whereas in York we’ve been more ambitious and generous.

We’ve created raised beds for shared growing. At all stages, Michael and his team have an eye on creating first-rate places to live.”

There has also been more local engage-

Renders: Mikhail Riches / Darc Studio | Drawings: Mikhail Riches

YORK

ment and consultation at York. The council hired Angela Koch, from planning consultancy Imagine Places, to connect the design team and client with local stakeholders. The team met local businesspeople and residents to do demographic analysis of areas, then spatially map out facilities and services. They then held workshops with residents in local churches or community centres. “We used building blocks representing houses, or trees, or cars, and asked residents to move them around. The community became part of the design process detailing each project’s objectives and working with the design team to build it. They had to make all kinds of tradeoffs and we found that residents pushed us towards having more trees, more green space and fewer car parking spaces. Given York is such a flat city, it’s a place you can live happily without a car, although we’re trying to put in car hire in every site. You can have a car for a few hours rather than one that sits on the driveway 90 per cent of the time.”

The first two zero carbon sites designed by Mikhail Riches are at Duncombe Barracks, on Burton Stone Lane in the Clifton ward, and Burnholme, in the Heworth ward. Both developments have planning permission and Jones has signed a contract with Caddick Construction to build them. Construction of Duncombe Barracks’ thirty-four homes, and one commercial unit, will begin this summer and is expected to take 18 months.

Meanwhile, the construction of the eighty-

ph+ | york case study | 29

YORK

CASE STUDY

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CASE STUDY

YORK

We’ve created raised beds for shared growing.

three Burnholme site homes will follow on a few months later. A third project on Ordnance Lane with eighty-three new homes has just won planning approval. More sites are under discussion and will follow.

Each location has a mix of one-bedroom flats and houses of various sizes. Currently 40 per cent are affordable homes, which is roughly half council housing and half shared ownership. But Jones says the council wants to get grant funding to increase the number to around 60 per cent of the total. The council has also introduced a priority scheme for key workers. “The vast majority of projects are now mixed tenure. If we did 100 per cent affordable housing schemes, we’d run out of funding quickly. This way the sales’ receipts help to cross-fund the development and it’s not exclusive in any way. It should allow us to keep doing this for years,” he says.

An important element of the inclusivity, he says, is that some of the homes allow two generations of the same household to live independently within them. “Britain is the most age-segregated society in Europe and we’re passionate about creating communities with mixed demographics. With some of the homes, the ground floor is a self-contained flat, so the property will have two separate kitchens. The living room will have a connecting door to the main house upstairs which will support the larger family. This type of co-living could be suitable for grandparents, who might want their independence, but also need to be close to their family for support. It allows flexibility and you get the benefits of the physical strength of younger people with the wisdom of older people.

“We feel that this could be a great alternative to a care environment for many families, which our residents tell us is the last resort, but one people often feel forced to take because of a lack of alternative options.

This design might also work well for sons or daughters who have come home from university and can’t afford to buy their own home yet, or for other family members with

care or support needs.”

The projects aim to encourage sociability to avoid the modern plague of social isolation, says Councillor Denise Craghill, York’s executive member for housing and safer neighbourhoods. “The shared spaces, including the raised beds and the ginnels, encourage socialising outdoors. It’s similar to something we’re seeing in existing Victorian terraces in York which is the greening of spaces between houses. At the front of the houses we’re creating play streets where children can scoot around and people can meet up,” she says. Craghill says it will be interesting to observe how the major house builders react to the high quality of the homes, as well as their extra environmental credentials.

Another aspect of the scheme which may raise eyebrows among house builders and planners alike is density, with Burnholme, Duncombe Barracks and Ordnance Lane re-

(top left) York councillor & executive member for housing Denise Craghill visiting site with Caddick Construction director of housing Richard Greenwood. (bottom left) Pictured at Duncombe Barracks site, where public engagement boxes were placed are (l-r) Mikhail Riches senior architect Sophie Cole, ImaginePlaces founder Angela Koch, councillor Craghill and City of York’s head of housing delivery and asset management Michael Jones.

ph+ | york case study | 31

YORK

CASE STUDY

AECB short courses at Built EnvironmentAECB AECB short short courses courses at at Built Built EnvironmentEnvironmentSmarter Transformation (BE-ST) Smarter Transformation (BE-ST) Smarter Transformation (BE-ST)

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It seeks to set and increase knowledge around the fundamental It seeks to set the context and increase knowledge around the fundamental It seeks to set the context and increase knowledge around the fundamental principles of well-considered building and retrofit design.

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For the opportunity to be awarded a place For the opportunity to a For theFabric opportunity to be be awarded awarded a place place on the First Approach AECB module, on the Fabric First Approach AECB module, on the Fabric First Approach AECB module, register your interest: register register your your interest: interest:

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https://tinyurl.com/fabricfirst https://tinyurl.com/fabricfirst 32 | passivehouseplus.co.uk | issue 42 https://tinyurl.com/fabricfirst

training@aecb.net training@aecb.net training@aecb.net

CASE STUDY

Car use is discouraged; every home has a bike shed.

spectively delivering 40, 52 and 62 dwellings per hectare, chiefly consisting of two-storey dwellings, along with some three-storey apartment buildings. (By comparison, the Irish government’s recently announced Croí Cónaithe scheme to support developing apartments for owner-occupiers requires a minimum density of 35 units per hectare – and a minimum of four storeys). “The differences reflect the different context of the projects,” says Michael Jones. “Burnholme is a very suburban setting and Ordnance Lane is more urban, being a short walk or cycle from the city.”

Mikhail Riches had achieved a remarkable 82 units per hectare for Goldsmith Street, but differing considerations allowed a relaxation in this case. “Part of this is around the client brief for the projects to be landscape-led and we are delivering more public open space than planning policy requires,” says Jones. “I was at a local plan hearing last week when developers were saying our proposed local plan density targets are unachievable. I think [these schemes] demonstrate that you can achieve high density with national space standards and house sizes, at

low heights, and create high quality public open spaces with biodiversity net gain.”

As York is in the north of England, where daylight hours are shorter than in the south and the sun is at a lower angle, Mikhail Riches had to work out how to stop overshadowing from blocking the sunlight in winter. This involved modelling the roofscapes so the sun penetrated the ground floor windows in the kitchens and dining rooms. “It was a lot harder to achieve than Norwich as the angle of the sun is different,” Mikhail says.

In the short term, Michael Jones thinks some councils will be put off building passive houses, and zero carbon homes, because of the higher cost. But he expects it to become more mainstream. “Changes to building regulations will push all new builds to passive house. Costs are a bit of a barrier, but they will fall. A bigger issue is there are so few architects, or builders that have built passive houses. Early adopters like York will help to drive change by upskilling the market and getting our region ready to deliver the standard,” he says.

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on passivehouseplus.ie & passivehouseplus.co.uk

YORK

SELECTED PROJECT DETAILS

Product details reflect initial specification and are subject to change Developer: City of York Council Architect: Mikhail Riches M&E design: LEDA Civil & structural design: Civic Engineers Passive house consultant: WARM Project management: Turner & Townsend Main contractor: Caddick Construction Quantity surveyor: Turner & Townsend Timber frame supplier: Roe Ltd Airtightness products: ProPassiv, via Green Building Store; Tremco Illbruck, or equivalent Brise soleil: Cadisch MDA Air source heat pump: Valliant DHW cylinder: McDonald Water Storage Steel panel radiators: Stelrad MVHR: Zehnder Pitched roof PV: Viridian Flat roof PV: Bisol Blown cellulose: Warmcel, or equivalent External wall insulation: Permarock, or equivalent EPS insulation: Jablite, or equivalent Mineral wool slabs: Knauf, or equivalent Windows & doors: Idealcombi, or equivalent Clay facing brickwork: Crest BST, or equivalent Lime mortar: Limetec, or equivalent Oak flooring: Tarkett, or equivalent

ph+ | york case study | 33

YORK

CASE STUDY

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618 (kg CO e) 2

Operational Carbon Result:

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Total = 4,374 (kg CO e) 2

TM65 Embodied Carbon Results with Refrigerant Leakage (kg CO₂e)

Operational Carbon Estimate (kg CO₂e)

Potential carbon savings vs a gas boiler

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

Operational carbon data for heating requirements, according to heat pump ErP fiche at medium temperature (55ºC), average climate conditions and equivalent boiler heat output. (Does not include thermal store data). Gas boiler assumptions: embodied carbon of 300kg CO2e, efficiency of 93%, service life of 15 years.

Carbon factors sources: Electrical grid according to Greenbook forecast for residential use. (source: gov.uk, IAG spreadsheet toolkit for valuing changes in greenhouse gas emissions, sheet conversion CO₂). Gas network according to SAP 10.1 carbon emissions factor (source: BRE Group, SAP-10.1-01-10-2019, Page 171).

QUHZ-W40VA - Product Information Type of product

A2W Heat pump

Capacity of equipment (kW)

4

Product weight (kg)

55.85

Material breakdown for at least 95% of the product weight? (Y/N)

Y

Service life of the product (years)

15

Type of refrigerant

R744

Refrigerant GWP

1

Refrigerant charge (kg)

1.15

Energy consumption of the factory per unit of product (kWh)

14.08

Location of manufacture

Asia

Product Complexity

Category 3: High

ecodan.co.uk

34 | passivehouseplus.co.uk | issue 42

Embodied Carbon Result with 'Mid-level TM65 Calculation' Method:

CASE STUDY

YORK

EMBODIED CARBON York wanted to reduce the embodied carbon of the construction by avoiding carbon-intensive materials like concrete, while using timber frames. David Mikhail thought carefully about how to fulfil York’s request. “It’s incredibly difficult. Until we decarbonise the industry, we’re not getting low-carbon bricks.

Since the Grenfell Tower disaster, it’s hard to get insurance companies to look at anything involving timber. And building control is also anxious about timber. As a result, it’s hard to get a mortgage for a building with, for example, timber cladding or timber decking on a balcony. It means we’re forced down the route of steel, glass and cement. But York has used timber frames for the superstructure and we’ve clad it in either brick, or clay tile. And we’ve used cellulose insulation, such as recycled newspaper, or wood fibre blown-in insulation, which gets the buildings into line with the RIBA 2030 Climate Challenge guidelines,” he says. In this regard, Passive House Plus played a hand, by introducing Mikhail to Tim Martel, creator of the AECB’s embodied carbon calculation tool, PHribbon, who did some consultancy for Mikhail Riches before the project began. Caroline Martin of passive house consultants WARM then used PHribbon, with Martel helping define the scope, to calculate the scheme’s embodied carbon scores.

The scope of the assessment – which focused on three blocks of terraced homes and apartments at Duncombe Barracks – is largely complete, including virtually all elements required for the RIBA 2030 Climate Challenge, albeit with incomplete information for building services (the MVHR system, heat pump, pipework and ductwork included), and fixed furnishings and equipment (WCs, basins and kitchen sinks were included). As per RIBA, external works were excluded. The

results are indicative only – default data was used in many cases, or if EPDs weren’t available for a given product in the spec, default values or data from a comparable product was used. Blocks B and C meet the RIBA 2030 target of 625 kg CO2e/m2 GIA, with scores of 595 and 587 respectively while Block A scores 642.

Taking Block A for instance, a large part of the reason for this score is down to what may be regarded pessimistic assumptions about the lifespan of components, and about their end of life. 397 kg of CO2e/m2 are estimated to be released by the point of practical completion (module A). By this point the building is also estimated to be sequestering 197 kg CO2e/m2 in the bio-based materials used such as timber and cellulose.

LC LC

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16

B04 0.04 A: 83.8m2 Flat Type G

LP

1

8

8

9

STORE

A: 1.5 m2

9

9

10

10

F/F

10

2 3 4 5 6 7 8

BIN STORAGE

F/F

11

WM

WM

WM

7

11

1

F

F

W

F

W

F

WM

LB

FF

MVHR

3

7

7

2

6

6

8

1

5

7

6

4

6

5

3

5

4

2

4

5

FF

1

4

8

3

3

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2

2

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3

9

2

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1

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16 15 14 13 12 11 10 9

16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1

1 2 3 4 LB

5 6 7 8 LB

9 10 11 12 13 14 15 16

LB

LB

LB LB

WT

LB LB

LB

CAR CLUB

WT

BIKE x 2

ELECTRIC VEHICLE

LB

F

3

7 8

8 7

2

6 5 4 3 2 1

6 5

6 5

4

4

3

1

5

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9 8 7

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F/F

8 7

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6

9

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11 10

8 7 6

4

ELECTRIC VEHICLE

11 10 9

2

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9

2

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6 5 4 3 LB

W

W

WM

2 1

LB

Scale 1:1000

0

1

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3

4

5

10 m

The use phase (module B) adds a predicted 213 kg CO2e/m2 due to material repair and replacement assumptions. For instance, the PV arrays are assumed to need two replacements within the 60-year reference life for the building, and the heat pump and MVHR system are assumed to need three replacements. In well designed buildings such as these, taking account of what we know about the lifespan these kinds of technologies can achieve, may fewer replacements be more realistic, subject to maintenance? And bearing in mind the strides some manufacturers are already making to radically reduce upfront emissions, is it really reasonable to assume that, say, a replacement heat pump installed 15 or 25 years from now will have similar embodied carbon to machines made today?

The end of life phase (module C) adds a further 230 kg CO2e/m2. Principally, this is because of the assumption that the CO2 sequestered in the timber and cellulose is released into the atmosphere – including the default assumption that the bulk of this material goes to landfill, and breaks down as methane.

However as the article on Joe Lyth’s timber frame house in New Zealand demonstrates (see page 8), it is possible – at least based on New Zealand data – to assume the vast majority of sequestered CO2 in landfilled timber does not break down, and remains sequestered. Based on current rules, this would create a curious state of affairs. If timber is reused or recycled at the building’s end of life, the sequestered CO2 in that timber moves outside of the boundary conditions of the building, and passes on to the next use. However if the timber is landfilled, and if it’s assumed not to decompose in the landfill, then the sequestered CO2 needn’t be deducted – creating an incentive to dump rather than reuse timber.

ph+ | york case study | 35

YORK

CASE STUDY

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josko.com 36 | passivehouseplus.co.uk

| issue 42

CASE STUDY

YORK

IN DETAIL This information panel focusses on a 111 m2 terraced two-storey three-bedroom house at Duncombe Barracks, York, part of a wider mixed-tenure development of thirty-four homes designed to the passive house standard. This development will have a range of sizes and types including eleven one-bed flats, eight two-bed terraced houses; nine three-bed terraced houses, and six four-bed terraced houses. Energy performance metrics are targets rather than measured figures. Product details reflect the initial specification and are subject to change.

Building type: A typical 110.71 m2 terraced two-storey, three-bedroom house Location: Duncombe Barracks, Burton Stone Lane, York Completion date: December 2023 Budget: £13.69 m including land, works and on-costs for the whole development including thirty-four homes, one commercial unit, and high-quality public realm that comprises a central green space and a small civic square.

Passive house certification: Aiming for PH classic standard Space heating demand (PHPP): 15 kWh/m2 Heat load (PHPP): 10 W/m2 Primary Energy Renewable (PHPP): Aiming to be below the PER limit of 60 kWh/m2 Heat loss form factor (PHPP): 2.24 for the whole terrace (comprising houses & flats) Overheating (PHPP): Designed for 0 per cent Number of occupants: 5-person household in this example; 141 at Duncombe Barracks in total.

Environmental assessment method: Aiming to achieve carbon net zero in operation in line with the LETI framework.

Airtightness (at 50 Pascals): 0.6 air changes per hour Predicated energy consumption: 35 kWh/m2/yr

Energy bills (estimated): As low as £300 per year based on domestic energy costs from 2021.

Based on PHPP estimates, City of York Council estimates that this example property could have a total electricity bill of £300. This includes standing charges but also savings/feed-in-tarriff from the solar PV array. The council says that this should be considered, “a very estimate as it is impossible to predict occupier behaviour. It could be considered an ambitious target that can be achieved with the right education and support.”

Thermal bridging: Thermal bridge values have been assumed for step backs, balcony structures, internal walls to floor and party wall to floor junctions. These are currently based on details from previous projects and will be calculated at the next stage if necessary. All other thermal bridging has been designed out. Preliminary calculations have been undertaken for window installation values; these will be further refined at the next stage if required.

Ground floor: 75 mm reinforced concrete topping, followed underneath by Visqueen vapour barrier, 225 mm Celotex foil-faced PIR board (thermal conductivity 0.022 W/mK), Visqueen EcoMembrane loose-laid polyethylene DPM, 225 mm Jetfloor insulated beam and block floor system (Infill blocks: 150 mm EPS grey insulation blocks; thermal conductivity 0.030 W/ mK), 250 mm void, 750 x 900 reinforced concrete footings. U-value: 0.083 W/m2K Walls: 102.5 mm brick on 50 mm cavity; or 7 mm PermaRock silicone render on 140 mm PermaRock mineral fibre insulation; followed inside by breather membrane (Pro Clima Solitex Plus), 400 mm timber frame construction with 380 mm Warmcel insulation, 13 mm Smartply Propassiv board as airtight layer, 45 mm cavity insulated with Knauf Earthwool, 15 mm plasterboard and skim. U-value: 0.097 (brick cladding build-up) and 0.80 (silicone render) W/m2K

Pitched Roof: Clay Pan Tile, followed underneath by battens & counter-battens, breather membrane (Pro Clima Solitex Plus), 400 mm timber frame insulated with 380 mm Warmcel insulation, 13 mm Propassiv Board used as airtight layer, 45 mm cavity insulated with Knauf Earthwool, 15 mm plasterboard & skim. U-value: 0.097w/m2K Flat roof: IKO Spectratex polyester protection fleece, followed underneath by 200 mm / 300 mm IKO Enertherm tapered PIR roofboard, IKO Systems metal-Lined bituminous VCL, 25 mm plywood (WBP) & OSB3, 150 mm Knauf Earthwool, 400 mm timber frame with 380 mm Warmcel insulation, 13 mm Propassiv Board used as airtight layer, 45 mm cavity insulated with Knauf Earthwool, 2 x layers 15 mm plasterboard, skim.

U-value: 0.0106 & 0.072 W/m2K (depending on PIR insulation depth).

Windows & external doors: Ideal Combi Futura+ triple glazed aluclad windows and doors.

Heating system: Vaillant AroTherm Plus 3.5 kW air source heat pump with seasonal efficiency of 365 per cent supplying low temperature radiator heating system and a super insulated 180 litre domestic hot water cylinder.

Ventilation: Zehnder heat recovery ventilation systems.

Water: Rainwater harvesting via water butts. Low flow fittings on all plumbing fixtures.

Electricity: 22 m2 Clearline Fusion PV system with average annual output of 5 kW per dwelling. No on-site storage, excess electricity will be exported to the grid.

Green materials: Cellulose insulation, timber frame construction.

Transport: Low number of car parking spaces, car clubs, free-to-hire e-cargo bikes, generous bike storage.

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GOING SWIMMINGLY DEVON COMPLEX IS SET TO BE UK’S FIRST PASSIVE-CERTIFIED LEISURE CENTRE The environmental journalist George Monbiot has written about how we need an era of ‘public luxury’ and ‘private sufficiency’ — as opposed to private luxury for the few — to mitigate overconsumption and climate breakdown. And it’s hard to think of a better example of public luxury than this superb new leisure centre in Exeter, which consumes just a fraction of the energy of typical facilities, and is set to be certified to a bespoke version of the passive house standard.

By Peter Rickaby

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IN BRIEF Building: 6,700 m2 leisure centre Method: Mix of reinforced concrete, concrete blockwork, cross-laminated timber and lightweight steel frame.

Location: Exeter, Devon Standard: Passive house certification pending Utility bills: £20/m2 per year (vs £57/m2 per year for a conventionally built leisure centre, see ‘In detail’ for more) prior to recent price spikes. Predicted net cost of £230/year post price spikes.

£20

/m2 per year

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M

any of us have childhood memories of swimming lessons at local pools or leisure centres that were chilly, draughty, noisy and pungent with the aroma of chlorine. My later, professional memories of leisure centres are of twentieth-century gas guzzlers, usually the most energy intensive buildings in local authorities’ stocks, typically using 1,573 kWh/m2/yr – comprising 237 kWh/m2/yr for electricity, and 1,336 kWh/m2/yr for heating – according to CIBSE. Exeter City Council’s new leisure centre

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at St Sidwell’s Point is different. The expected 500,000 visitors per year will enter a typically passive house environment – calm, quiet, comfortably warm and brightly daylit. There is no smell of chlorine – the water in the pools at St Sidwell’s Point contains less chlorine than tap water. The building will use less than 375 kWh/m2/yr (the passive house target for this building, which the project team expects to beat) – a 76 per cent saving compared with typical leisure centres, and a 49 per cent saving compared with recent good practice. It also delivers

a 50 per cent saving in water use, while providing exceptional internal air and water quality. The building is resilient against predicted climate change until 2080 and conforms to Building Biology IBN best practice in healthy building design.

St Sidwell’s Point Leisure Centre is set to be the UK’s first passive house certified leisure centre. It is also the product of Exeter City Council’s commitment to sustainability and the passive house standard, delivered by Gale & Snowden Architects and Space & Place Architects, working with Arup and the main contractor Kier.

The 6,700 m2 building (4,850 m2 TFA) provides two swimming pools (25 m and 20 m long, with moveable floors to provide variable depths), a toddlers’ confidence pool, a 100-seat spectator area, a 150-station gym, a spin studio, a fitness/dance studio, a health spa with a hydrotherapy pool, changing facilities, a soft play area, a café and administrative offices.

Space & Place were the lead architects, responsible for the interiors. Gale & Snowden Architects were the passive house designers and were responsible for the building envelope design, including airtightness and thermal bridge free construction. Gale & Snowden also provided passive house consultancy for the services design, dynamic simulation modelling of thermal performance, daylighting, overheating risk and resilience against climate change, as well as building biology consul-

CASE STUDY

The water in the pools contains less chlorine than tap water.

tancy covering healthy building principles and the selection of materials. Arup were structural and services consultants. The main contractor Kier, and the sub-contractor T Clarke, who designed and installed the services, were integral parts of the team that delivered the building.

For most passive houses, the energy strategy involves consideration of a single zone, modelled using PHPP. The St Sidwell’s Point project is more complex because the building inevitably contains several zones with different environmental requirements and energy characteristics.

For example, pool areas require heating (including the water), and must cope with evaporation of pool water into the space; by contrast, the gym, the spin studio and the fitness/dance studio are sources of heat, which often require cooling. This led to an energy efficiency strategy based on several zones, with different requirements, located in different parts of the building – and carefully separated.

No zones are open plan to each other.

The two large pool spaces are located on the

Photos: Tom Hargreaves

highly glazed south and west sides of the building, where they benefit from free solar heat gains; they are in separate zones with slightly different orientations, heat losses and heat gains, and they are separated by glass partitions with well-sealed doors. The gym and studios produce heat gains from equipment and energetic people; they are located on the north and east sides of the building. To cool the gym and studios without throwing energy away, a heat pump removes heat and uses it to heat the pool water and other parts of the building.

Zones with intermediate environmental requirements are located in the centre of the plan where they function as thermal buffers. Several plant rooms, large and small, are distributed around the building,

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to serve adjacent zones with different environmental requirements and to minimise the lengths of pipes and ducts.

The energy efficiency of the pool spaces is optimised by keeping them warm (31C for the main pool) and humid (64 per cent relative humidity) to minimise evaporation of pool water – thus reducing the latent heat of evaporation, which is a significant heat loss that has to be made up by the pool plant. The two smaller pools are also drained at night to reduce evaporation losses. With reduced evaporation, ventilation rates could also be reduced to less than half that of an ordinary pool, as less dry air is needed.

Pool water filtration is a significant energy demand, typically accounting for approxi-

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The building uses 70 per cent less energy than a more conventional leisure centre.

mately one-third of the electricity used in a pool building, and it is not covered by building regulations, so there is often little incentive to reduce it. At St Sidwell’s Point, a microfiltration system combined with ultra-violet sterilisation was adopted, providing more efficient filtration and minimising chlorination, with less backwashing.

The Passive House Institute set a challenging energy target of 40 kWh/m2/year for pool water circulation and filtration. This required careful planning and co-ordination of the pipework systems in order to reduce pressure drops to meet the target. In addition, the pipework had to sit within a thermal envelope adjacent to the pool tanks in order to limit heat loss. In typical schemes it is buried in the ground uninsulated.

The early stage dynamic modelling identified that there was a significant energy load in the gym and spin studios that could be used to heat the pool water and other parts of the building. One hundred and fifty gym users working out on a daily basis, plus the spin studios, produce elevated levels of heat gain. This drove the use of hybrid air source heat pumps which can deliver heat and cooling simultaneously. All of the waste heat from these spaces can be used for the majority of the water and space heating, resulting in a heat pump total efficiency ratio (TER) of seven.

In addition, a water source heat pump is used to recycle waste heat from the filtration backwash to top up the water heating. The backwash water is then recycled for flushing toilets. Overall, this system contributes to the 50 per cent water use reduction the scheme has realised, as well as reducing the pool water heating load.

The building also has passive house certified high efficiency heat recovery air handling units with variable volume carbon dioxide, temperature and relative humidity control, inverter-driven variable speed pumps and LED lighting throughout (less than 3 W/m2).

Form balancing efficiency & zoning The form of the building reflects the energy efficiency and zoning strategy. The site in the centre of Exeter slopes downhill to a large

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traffic roundabout, to which the building presents a cascading series of curved forms incorporating the highly glazed south and west elevations of the pool halls. These elevations are stepped back over two storeys to split the triple glazed facades into two, the lower sections being equipped with louvres to stop glare on the pool surface interfering with spectators’ views.

The stepped roofs over the pool halls are supported by two huge, laminated timber trusses, spanning dramatically above the centrelines of the pools. Seen from the south and the west, the building is a curvy, shiny and layered composition of glass, smooth cladding and deep overhangs. The other two elevations are similar but simpler and less dramatic, because there is less need for solar control and they are more intimately associated with the adjacent city centre buildings.

The structure and construction of the building are complicated, combining reinforced concrete, concrete blockwork,

cross-laminated timber and lightweight steel frames with sheathing boards. Given the complex geometry of the building, achieving a highly insulated, thermal bridge free and airtight passive house envelope was described by the project team as the biggest challenge of the job. Attention to detail and numerous checks were required. Much effort was made to engage and train site operatives, including regular workshops to explain what was required and seek feedback. More than two thousand individuals went through this process, each receiving a ‘passive house passport’ in recognition of their acquired learning and skills. Mock-ups of key construction details were made for testing, training and for building confidence that they would work on site. Kier’s senior project manager, Joe O’Connell, remarked: “We were amazed at the buy-in we got from the supply chain and how proud those people are of the work they do. If you take them on the journey and take the trouble to explain

CASE STUDY

what you are doing – and why you are doing it and the benefit and what that means to them – most of the people on this site were coming up with ideas themselves and proud of what they were doing. It’s almost unheard of in my experience.”

Care and diligence were rewarded when the building envelope achieved an air permeability of 0.3 m3/m2/hr at 50 Pascals (equivalent to 0.1 air changes per hour), well within the passive house certification requirement.

The interior layout of the building is complicated, reflecting both the shape and slope of the site and the zoning strategy.

A central feature is the fiendishly complicated, twisting central stairway, which provides access to multiple levels. All spaces except the changing areas are day-lit, and those on the highly glazed south side are bright and dramatic. The spaces on the north side of the building have smaller windows that provide a variety of intimate views of the surrounding town. The materials are natural, and mostly light in colour.

Stair treads are wood, balustrades are laminated glass topped with timber handrails, and the pools and gyms have slatted timber ceilings. Walls and floors in the pool spaces and changing areas are finished with ceramic tiles. Overall, the interiors are modern, healthy, sustainable, reserved in style and neatly detailed, despite the challenges imposed by surfaces coming together at many angles.

Passive house certification of the building presented unique challenges. The Passive House Institute had previously certified two swimming pool buildings in Germany, but St Sidwell’s Point Leisure Centre is much larger and more complex.

At an early stage, Gale & Snowden developed a detailed dynamic thermal model which informed key passive house criteria in the context of the changing climate, using weather files from Exeter University’s Prometheus project. This model included fabric elements and services, and helped optimise orientation, glazing ratios, thermal zoning and the key ventilation and comfort strategies. This exercise provided understanding of key energy loads for each

The building is resilient against predicted climate change until 2080.

1

2

3

4

5

6

7

8

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1 Primary trussed glue-laminated beam being installed over the main pool hall; 2 curved facade with Wraptite airtight membrane and thermally-isolated secondary steelwork and stainless steel helping hand brackets with a thermal spacer; 3 stick pins retain a heavy breather membrane without penetrating the composite airtightness layer; 4 areas of backing wall exposed showing the layers of construction behind; 5 an internal wall at basement level forming the external envelope of the building; 6 mineral wool installed around curtain wall openings to reduce the thermal bridge at jambs, cills and heads; 7 taping of the window units to the airtightness layer at reveals; 8 the building’s Swegon Gold RX units, the first air handling units for commercial buildings to be certified components by the Passive House Institute.

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NOW PLAYING

WRAPTITE® THE SELF-ADHERING AIRTIGHT AND VAPOUR PERMEABLE MEMBRANE 0:03

01250 872 261 contact@proctorgroup.com

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SELECTED PROJECT DETAILS

thermal zone and of the balance between heat and ‘coolth’ between the zones, and helped to inform the heating and cooling services strategy.

The standard PHPP tool is only suitable for single-zone simple building designs and the Passive House Institute had to develop a bespoke PHPP model for the scheme.

Once this came together, the certification criteria were set for the key elements (see ‘In detail’ for the full list of bespoke certification targets).

St Sidwell’s Point Leisure Centre is a £44 million building that has to pay for itself from revenue – neither building costs nor running costs are funded by council tax.

The building has been designed for an eighty-year life, with 70 per cent less energy use than a more conventional leisure centre, and with a payback period of less than ten years.

St Sidwell’s Point has brought leisure centre design into the twenty-first century.

Building physics, the passive house standard and skilled architects and engineers have come together to create a striking piece of architecture that combines uplifting and healthy spaces with energy efficiency, all with attractive economics. As David Gale of Gale & Snowden puts it: “The building breaks new ground for the passive house standard and shows that it makes both financial and environmen-

tal sense when applied to complex buildings that traditionally use large amounts of energy – there is now no excuse not to adopt the passive house standard even for complex buildings.”

There are other large and complex passive standard buildings – for example The House at Cornell Tech, on Roosevelt Island in New York, by Handel Architects and Buro Happold, a 26-storey student residence that includes a laundry, a gym and a spin room. But St Sidwell’s Point, with its four pools and multiple zones, its healthy building biology and its resilience against climate change to 2080, shows how even the most challenging brief can result in a landmark building that combines certified passive house performance with a benchmark for sustainability. We can expect to see more passive house leisure centres in the future.

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on passivehouseplus.ie & passivehouseplus.co.uk

Client: Exeter City Council Lead architect: Space & Place Architects Passive house designer & building envelope architect: Gale & Snowden Architects Future climate resilience consultant: Gale & Snowden Architects Main contractor: Kier Structural & MEP engineer: Arup Cost consultant & employer’s agent: Randall Simmonds Pool filtration specialist: FT Leisure Mechanical & electrical contractor & services design: T Clarke Building biology consultant: Gale & Snowden Architects Passive house certifier: Passive House Institute Airtightness consultant & testing: WARM / Paul Jennings Airtightness membranes: A Proctor Group Cladding: AKV Roof system: Euroclad Plasterboard: British Gypsum Roof membrane: Triflex Passive house doors: Raynaers Windows, doors, curtain walling: Kawneer Glazing systems: AB Glass Ducted heat exchanger: Hoval Miscellaneous fans: Nuaire Air source heat pump: Mitsubishi Water-to-water heat pump: Menerga Pumps: Grundfos Engineered timber: Hess Timber Lifts: Kone Moisture resistant doors: Lami Doors Waterproofing: Walker Waterproofing Access flooring: Carrino Access Flooring Joinery: Blake Joinery Air handling units: Menerga / Swegon Structural framed steelwork: Metsec Secondary steelwork: AnyWeld / Tata Steel / Hewas Water Cladding sub-contractors: Massey Cladding Solutions / Dales Groundworks and primary concrete framing: Stephenson

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Great performance is the product of Hardware, Controls and Knowledge

Our GOLD RX is certified by the Passive House Institute for high energy efficiency with our rotary heat exchanger.

You can calculate the performance of a Passive House GOLD unit using our online configuration and selection tool by searching for Swegon AHU Design.

GOLD RX

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CASE STUDY

ST SIDWELL’S POINT

IN DETAIL Building type: 6,700 m2 leisure centre Location: Exeter City Centre Completion date: April 2022 Budget: Total construction costs for the building contract (i.e., not including professional fees, legal fees and all other client costs) was £34.5M. Passive house certification: Passive house classic certification pending Passive house certification criteria: Heating demand for pool halls: 40 kWh/m2/yr Heating demand for all other spaces: 20 kWh/m2/yr Total heating demand: 60 kWh/m2/yr Pool water heating: 73 kWh/m2/yr Domestic water heating demand: 0.7 kWh/m2/yr Cooling demand for gym spaces: 22 kWh/m2/yr Total energy use: 375 kWh/m2/yr Pool water circulation and treatment: 40 kWh/m2/yr Ventilation: 20 kWh/m2/yr Lighting|: 20 kWh/m2/yr Other appliances: 20 kWh/m2/yr Total electricity demand*: 120 kWh/m2/yr Airtightness (required Q50): < 0.4 m3/m2h Airtightness (recommended Q50): < 0.2 m3/m2h *All ventilation, lighting, appliances, pool water treatment and circulation Heat loss form factor (PHPP): 2.00 Overheating: The 25C overheating limit set in the passive house standard was not an appropriate metric to use (some zones are assigned to be 30C). The client briefing criteria regarding overheating was as follows: BS EN ISO 7730: Ergonomics of the thermal environment BS EN 15251: Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics.

Summer temperature criteria as follows, as defined in CIBSE Guide A: Offices 23 – 26C; swimming pool 30 – 34C; dry sports 14 –16C; hanging rooms 24 – 25C. The building was designed to be adaptable to meet predicted

future weather without affecting the energy consumption of the building or compromising healthy building principles. Gale & Snowden Architects thermally modelled the building using Prometheus Project (Exeter University) weather files to 2030, 2050 and 2080 under an IPCC 50 percentile high emissions scenario (scenario a1fi).

Energy performance certificate (EPC): Pending Thermal bridging: Due to the complexity of a leisure centre design all thermal bridges were unique. Every junction is a bespoke design. Due to the scale of the building thermal bridges were numerous and there was a detailed exercise to design them out and calculate them. This involved working closely with the Passive House Institute who reviewed all calculations and approved them.

Utility bills: The design team conducted a detailed exercise to assess the likely utility costs (electricity, gas and water) for a passive standard leisure centre versus a conventional build. This exercise found that the predicted utility costs for a conventionally built leisure centre would be £57/m2 per year, compared to £20/m2 per year for a passive standard leisure centre.

Ground floor: In-situ concrete flight-augured pile foundations and pile caps, concrete blinding, followed above by 250 mm Jablite Jabfloor 150 XPS insulation, Sika Sikaproof A08 waterproofing membrane, 300 mm reinforced in-situ concrete slab. U-value: 0.14 W/m2K Typical wall construction: 3 mm solid aluminium cladding panels externally, followed inside by aluminium vertical support rails, Proctor Fireshield breather membrane, 250 mm Knauf Earthwool RainScreen slab insulation, Systea Edelstahlhalter thermally-isolated stainless steel façade brackets, Proctor Wraptite self-adhesive vapour permeable membrane, 12 mm Euroform A2 Versapanel, 150 mm Metsec steel framing system, 2 x layers British Gypsum plasterboard.

U-value: 0.14 W/m2K Primary roof (above pool hall): Trussed glue-laminated beams, cross-laminated timber roof panels, followed above by Euroclad vapour control layer, Euroclad galvanised steel top hat and 25 mm thick Rockslab rigid insulation, 50 mm Rockslab rigid insulation, Euroclad 150 mm

TR26 polyisocyanurate insulation, Euroclad Rocbar spacer profile, 80 mm Euroclad insulation quilt, 0.9 mm Euroclad aluminium standing seam roof sheets externally. U-value: 0.091 W/m2K Roof 2: Mild steel primary structural frame internally, followed above by Tata D100 steel deck profile, 18 mm WBP plywood, vapour control layer, PIR insulation (250 mm to 783 mm depending on location), Triflex liquid-applied roof covering. U-value: Varies Windows & external doors: Kawneer RT82 HI+ PHI-certified inward-opening window system, U-value: 0.80 W/m2K; Kawneer AA100HI+ PHI-certified thermally broken curtain wall system, U-value: 0.72 W/m2K; Raynaers Masterline 8 PHI-certified door system, U-value: 1.25 W/m2K Roof windows: Lamilux CI FE rooflight, U-value 0.83 W/m2K; Lamilux CI FE manually operated access hatch, U-value 0.83 W/m2K. Heating & cooling: Simultaneous heating and cooling plus domestic hot water services by 212 kW Climaventa air source heat pump. Menerga 37 kW combined heat recovery and water-towater heat pump system from backwash tank (combined COP 11.4). This tops up DHWS loads.

Ventilation: There were 13 air handling units in total, all are passive house certified Menerga or Swegon units, with the exception of the pool halls as there are no certified models in this range. The pool AHUs were reviewed in detail and signed off by the Passive House Institute.

Water: Compared to traditional sand filtration systems, the microfiltration system for the pool requires less backwashing and up to 50 per cent water can be saved. With higher efficiency filtration coupled with UV sterilisation, chlorine levels are minimised to those better than drinking water. A water source heat pump is used to recycle the waste heat from the backwash water to top up water heating. Once the heat is removed, the backwash water is also recycled to flush WCs, contributing to the estimated 50 per cent water savings.

Materials: Materials have been chosen to comply with building biology guidelines as much as possible.

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BLOCK BUSTER GALWAY PASSIVE HOUSE BIRTHS LOW CARBON CONCRETE BLOCKS With emphasis in sustainable building shifting towards reducing embodied carbon, an obvious question comes into focus: is this an existential threat to the concrete industry?

One passive house in Claregalway shows that – with a little help from Passive House Plus – concrete product manufacturers can make meaningful moves in the right direction.

By John Cradden

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WAY N E H E S S I O N

IN BRIEF Building: Detached 260 m2 cavity wall house Method: Cavity wall Standard: Passive house classic certified Energy bills: €79.50/month total energy costs including standing charges and VAT. See ‘in detail’ for more.

€79.50 per month

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Hession managed to persuade Coshla Quarries to make blocks for him using GGBS

I

t’s sometimes thought that using traditional construction methods and largely standard details to build a new, passive house-certified home would be a (thermal) bridge too far for most Irish builders.

Passive house designer and owner of this impressive new, four-bed, 260 m2 certified passive house in Galway, Wayne Hession, did consider using timber frame and other methods perhaps more suited to meeting the onerous build and detail standards required. But between himself and Brendan Money of Robin Mandall Architects, they chose to use traditional masonry cavity wall construction mainly for cost reasons and access to local skills. “Everyone that was involved working in the house was either a friend or cousin or someone I’ve worked with,” he said.

Hession had spent some 20 years working in construction as an onsite engineer in England and Australia, before returning to Galway in 2014 with plans to build a new home on a site that’s been in his family for nearly 30 years. He planned to continue working in the sector on his return but the

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lack of work at the time pushed him into jobs as a BER consultant. He trained in a number of other areas, including airtightness testing and, later on, passive house design, while setting up his own company Hession Energy.

He had also worked with Robin Mandall Architects providing consultancy services, and had seen and loved Brendan Money’s work on a number of small residential projects. Despite having never worked on a passive house, Hession persuaded Money to take on the project and gave him practically a blank canvas to design a four-bedroom house with open-plan living areas — but not before briefing him on a few key principles to make it work as a passive house.

According to Money, these principles were to limiting north-facing openings, reducing solar gain by shading to the south, keeping the form compact and stacking the service rooms i.e., bathrooms and utility rooms.

“The site was a relatively level field, so it made sense to position the house to the northwest to take advantage of solar gain,” says Money.

“The form we developed respected the existing building line along the lane but we cranked the plan to orientate the form to the south more. The form is compact and deep on the northeast side, but the ridge line runs diagonally across the plan so that the roof begins and ends as a monopitch roof which reduces the impact of its volume.”

With fewer windows on the north side, the result is a building that opens up towards the south and into the massive lawn, with the timber and overhanging areas con-

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WAY N E H E S S I O N

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on passivehouseplus.ie & passivehouseplus.co.uk

The details are similar to how all masonry cavity wall houses are built

necting to the inside. “We let the constraints become the driver,” says Money.

Money’s first attempt at the design undoubtedly met with Hession’s early approval.

“I didn’t give him examples. Didn’t give him briefs. Didn’t give him photographs. Pretty much what you see is what he designed first time around,” says Hession.

Internally, there are a series of living spaces that link to a mezzanine room through a double height space over the dining table.

“Through shifts in the geometry and changing, the rooms are interconnected and open but have their own distinct character and presence,” says Money.

Hession is pleased that Money managed to incorporate open-plan living areas but also that the house was situated as far north as possible to expand the extent of the south-facing garden, in contrast to many other houses where architects tend to plunk the house straight and centre. “It basically

Photos: Stefan Hoare / Sheelin Photography

means that we have all this beautiful space.”

When the project was at design stage, Hession and Money met with Passive House Plus editor Jeff Colley, who suggested that a good way to reduce the carbon footprint of the build was to use concrete blocks made with 50 per cent of the cement substituted for Ecocem’s GGBS (ground granulated blast furnace slag), a steel industry by-product that has independently verified embodied carbon figures of up to 95 per cent lower than Portland cement. One obstacle that GGBS has always faced is the accusation that it can increase the curing time for concrete when added at higher percentages – an argument used to rule it out of use in blockwork manufacturing, where achieving early stage strength is key to enabling blocks to be lifted and batched, to avoid slowing down production. But Colley had learned that the architect Darragh Lynch specified blocks with 50 per cent GGBS on a phase of Ballymun Regeneration in 2012, with blockwork manufacturer Kilsaran using their curing chamber – a feature most blockwork manufacturers don’t have – to make the blocks without a hitch.

Hession got the bit between his teeth, and approached Martin Collins, general manager of Coshla Quarries in Galway, to run the idea by him. Aided by Ecocem, who developed an accelerant to enable GGBS to be added at high percentages for typical open air blockwork curing facilities, Coshla man-

ufactured 50 per cent GGBS high density concrete blocks for Hession. Aiming for 13 newton strength, independent compression tests showed results of 17 to 22n.

Given the continuing domination of concrete as the primary material in Irish construction, Hession believes more effort should be put into promoting the use of GGBS and other eco cements. “If the findings are that you’re reducing roughly by 50 per cent the carbon footprint for a block build, that’s massive,” he said, adding that GGBS often doesn’t figure much in ICF (insulated concrete formwork) where large volumes of reinforced concrete are involved.

Another innovation found inside Hession’s home is a system which combines ventilation with air-based heating and cooling, from Galway-based ventilation manufacturer ProAir. The intention was to install ProAir’s standard heat recovery ventilation system: the Passive House Institute certified PA 600LI unit. But the company’s CEO, David McHugh, asked Hession if he would consider a new product made in the Czech Republic called the Jablotron Futura, which integrates an air-to-air heat pump to the ventilation system to offer air-based space heating and cooling. Intriguingly, the system uses sensors in each room to offer demand control – for instance ramping up ventilation rates automatically in response to spikes in CO2 levels in particular rooms.

Hession says they have been using the sys-

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They haven’t ever turned on the underfloor heating upstairs

tem for active cooling recently because his wife Michelle is pregnant, and he describes it as very responsive. The house didn’t exceed 24C during the mid-July heatwave.

Hession had already specified an air-towater heat pump system for heating, so the Futura is used only for cooling. One teething issue relating to filters led to the system having to be switched off for a few weeks, but sensors installed as part of an NUI Galway air quality monitoring project in A-rated dwellings certainly illustrated how essential heat recovery systems are in airtight houses.

“Basically because the filters were from the Czech Republic, during Covid we couldn’t get them so we had to turn off the HRV for about five or six weeks. About three or four weeks into it, James [McGrath] from NUIG got in contact and asked was everything all right? He could tell from the data that our CO2 and humidity levels were off the chart.”

The self-build took two years, which was just enough time to move in before Covid began in 2020. “I think when you take your time building, you have a lot of time to iron out a lot of issues,” he said.

The hardest physical job was building the first floor, which involved installing Peri formwork, tying all the reinforcement and pouring the Ecocem GGBS concrete. “Myself and my brother used to work in Western Australia on large concrete projects so that’s why we decided to do it ourselves.”

In general, though, the build systems employed were fairly standard. Passive house U-values were achieved through using a cavity wall with 150 mm full fill insulation. Similarly the floor and roof use methods of construction that are common to masonry housing.

Hession modelled all the junctions for thermal bridging and generally used Mannok thermal blocks to eliminate thermal bridges. The junction details did not differ that significantly from the acceptable construction details (ACDs). There was initially a large thermal bridge between the soffit and the wall at the cantilevered section above the kitchen, but this junction was re-designed

by Bob Ryan of Earth Cycle Technologies, and the thermal bridge eliminated.

“I had imagined when we began that the passive house standard would mean elaborate detailing using specialised products to overcome thermal bridging, but this was not

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the case and the details are similar to how all masonry cavity wall houses are built,” says Money. “It helped that Wayne ensured the workmanship was exceptionally good. Good airtightness is also remarkably easy to achieve with well-built masonry construction.

“What I learned from this process with Wayne was that a passive house is not that much of a mystery. Using standard techniques and details, and following the basic principles of passive design, it is readily achievable. I think there is a common perception among architects that passive houses look the same way; small windows and a dull form dictated by minimising the building envelope. I’d like to think we have shown this is not the case and furthermore, standard materials and techniques can also be used to create a passive house.”

While Money’s involvement with the construction was limited, the geometry of the roof was a real challenge that required some refinements from him as the build progressed. “Easy to draw but hard to build,” Money says. “We provided a detailed set of drawings to set it out and the timber roof structure, with a lot of thinking, worked out. At the last moment, the plan to use an interlocking slate was abandoned as it was too complex to use. But to give Wayne his credit, he worked his way through the challenge we set.” The company supplying the interlocking slates said the pitch of the roof was right at the threshold for the warranty, so Hession decided to go with a Greencoat PLX colour-coated steel finish.

When they eventually moved in, the difference in temperatures between his parent’s 1970s built bungalow and his new home took a bit of getting used to. “The average

SELECTED PROJECT DETAILS

Clients: Michelle & Wayne Hession Project management: Wayne Hession Interior design/layout: Michelle Hession Architect: Robin Mandal Architects Ventilation: Partel Concrete blocks: Coshla Quarries GGBS: Ecocem Roof timber work: Long Life Structures Roof finish & cedar cladding: PJ Duggan Roofing Window and doors: J&N Windows Block laying and concreting: Dara Hession Block Laying Structural engineer: Charlotte Murphy Consulting Engineers Plumbing: Martin Duggan Plumbing Airtightness products: Siga Passive house certification & thermal bridge design: Earth Cycle Technologies Ground floor & cavity wall insulation: Xtratherm Heat pump: Firebird Ventilation & cooling: Jablotron, via ProAir Roof insulation: Dammstatt cellulose, via Ecological Building Systems Additional roof insulation: Isover Thermal breaks: Mannok, Puren Roof windows: Velux Landscaping: Mike Ryan Landscaping

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WAY N E H E S S I O N

temperature [in his parents’ house] was around 18 or 19C and then all of a sudden we went into this house where even now, the temperature is always comfortable even with heating off for two or three months. But you do get used to it.” They haven’t ever turned on the underfloor heating upstairs, they just turn on the ground floor heating at night, every second or third night, during the coldest months of the year.

Hession is still doing work on the landscape and building an adjoining garage, projects that will likely take another two or three years, and which include a long term plan to form berms and plant trees to provide shelter from the wind.

For now, the house is already sheltered from the worst of the energy price rises to come. For the first 12 months, the all-electric energy bill came in at under €960 for the year, but they’ll surely only be paying not much over a grand in 2022.

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1 Reinforced concrete raft foundation with 60 per cent Ecocem GGBS; 2 two courses of Mannok blocks at inner leaf; 3 150mm Xtratherm full fill cavity insulation; 4 Mannok blocks around window openings; 5 Purenit thermal breaks under sliding door; 6 Blowerproof airtight paint at the floor to external wall junction; 7 Xtratherm insulated floors and upstands; 8 Siga Majrex airtight membrane over 320 mm deep rafters at 600 mm centres; 9 rafters filled with cellulose and 100 mm metac insulation in the counter battens.

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EMBODIED CARBON

By Jeff Colley Spurred on by PHribbon creator Tim Martel, I took on the challenge of attempting to calculate the embodied carbon of the Hessions’ house myself, using PHribbon. It proved an insightful process made more challenging by the absence of robust, independently verified data for the project’s main embodied carbon innovation: the low carbon blockwork.

I felt some degree of personal responsibility to establish the benefit of this specification given that I had suggested low carbon concrete blocks to Wayne in passing, without expecting him to find a blockwork manufacturer willing to make them. Irish EPD consultant Peter Seymour of Eco Review kindly assisted me by putting some indicative calculations together, looking at manufacturing stage emissions, based on the blockwork recipe used by Coshla. The results are striking. Had all cement in the blocks been CEM I Portland Cement, the total per m3 of blocks would have come to an estimate of over 145 kg CO2 per m3. But the 13 newton blocks used contained 50 per cent GGBS, and 50 per cent CEM II cement, virtually halving the estimated carbon footprint, with a score of 73.8 kg CO2 per m3.

This decision alone resulted in a net saving of over 6 tonnes of CO2 for the house. 60 per cent GGBS was used in the ground floor slab, and 50 per cent GGBS in the first floor slab, resulting in an estimated reduction of circa 13 tonnes of CO2 compared to CEM I slabs. Almost three tonnes more were saved by opting for a 38 mm Cemfloor screed compared to a standard 75 mm sand and CEM I cement screed.

The project was assessed against the RIAI 2030 Climate Challenge, including an assumed 50-year life cycle, and lifespans of materials were kept in line with assumed values in default data or EPDs for products used. External works were omitted, as were enabling works and groundworks – the impact would have been insubstantial, as only three truckloads of soil were excavated, and transported for use on a farm 100 metres away. The scope of the assessment is not complete, but covers all of the major items – including the substructure, external and internal walls, the roof structure, and all internal and external finishes to walls, ceilings and

floors with the exception of paintwork throughout and the bathroom tiles.

The staircase, balustrades and internal doors were omitted. Windows were included – albeit relying on data from a similar product with an EPD - as was all insulation and thermal breaks, and approximations in case of the main building services items. In the absence of an EPD for either the Jablotron Futura unit or Enviroair air-to-water heat pump, data was taken from the closest available certificates – a Product Eco Passport (PEP) for a 4 kW compact unit, and an industry association generic PEP for air source heat pumps.

Lifespans of the two units were assumed to be 17 years each, as per the PEPs, and default refrigerant data was replaced by data on the actual refrigerants used in both cases, with leakage rates in line with CIBSE’s TM65 methodology.

Ventilation supplier ProAir provided a detailed breakdown of the distribution system, including the weight of all plastic ductwork used, which enabled a calculation of the embodied carbon of this aspect based on generic PVC data.

Underfloor heating and hot water pipework was not included.

The Hessions plan to install a solar PV array of at least 6 kWp, and this was factored in. Assuming the lowest embodied carbon result for a PV monocrystalline module – the Sunpower Maxeon 3, the modules would add two tonnes to upfront emissions, a figure which would be assumed to double over the building’s full lifespan, assuming the array is replaced once within that time. If a higher embodied carbon module is used instead, the total for PV could quadruple, and increase the whole building embodied carbon total by over 10 per cent.

The net result: the building scores just under 97 tonnes of CO2e, or 373 kg CO2e/m2 GIA, indicating it’s likely to beat the RIAI 2030 target of 450 kg CO2e/m2 GIA for homes of over 133 m2. While decisions taken with the project regarding GGBS use greatly helped to reduce the embodied carbon, there’s no doubt that the house benefits from its comparatively large size, when considered against the RIAI’s target for homes above 133 m2 – a perhaps unfair advantage, given the house comes in at more than twice that size threshold.

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IN DETAIL Building type: Detached 260 m2 cavity wall house Site & location: Rural site, Claregalway, Galway Completion date: February 2020 Passive house certification: Passive house classic certified Space heating demand (PHPP): 14.15 kWh/m2/yr Heat load (PHPP): 9.74 W/m2 Primary energy renewable (PHPP): 38 kWh/m2/yr Overheating (PHPP): 0 per cent of hours above 25C Number of occupants: 2 (with a third expected imminently) BER: A2 (provisional) Energy bills: Electricity bill for the full year was €954 including VAT, standing charges and PSO levy (09/11/2020 to 09/11/2021).

Estimated heating cost: €36 per month including VAT. Based on Bonkers.ie cheapest

rural tariff as of 4 August, including 23.23c day date and 12.62c night rate.

Airtightness (at 50 Pascals pressure): 0.44 ACH or 0.593 m3/m2/hr Thermal bridging: Mannok blocks used around all the window and door junctions. Purenit under all the external doors and sliding door.

Ground floor: Reinforced concrete raft foundation with 60 per cent GGBS, 150 mm Xtratherm XT/UF, 38 mm Cemfloor screed.

U-value: 0.14 W/m2K Walls: Render externally followed inside by concrete block (50 per cent GGBS), 150 mm Xtratherm Cavitytherm in a 155 mm cavity, with Mannok thermal block at window opes and first two courses, cement plaster airtight layer, gypsum plasterboard. U-value: 0.132 W/m2K Roof: Greencoat PLX colour coated steel, followed underneath by battening, breather membrane, OSB3, 350 mm Dammstatt cellulose between rafters, Siga Majrex airtight membrane, 100 mm Metac insulation between battens,

counter battens, plasterboard internally.

U-value: 0.105 W/m2K Windows: Internorm KF410 uPVC/aluclad triple glazed windows. U-value of 0.74. Installed U-value (PHPP): 0.8 – 1.0 W/m2K Roof windows: Velux triple glazed Passive House Institute certified roof window.

Overall U-value: 0.80 W/m2K (PH cert) Heating system: 7.5 kW Firebird EnviroAir air-to-water heat pump supplying underfloor heating throughout. Seasonal performance factor 370 per cent (Harp Database).

Ventilation: Jablotron Futura combined ventilation, heating and cooling unit. Passive House Institute certified heat recovery rate 90 per cent. In this case the system does not provide heating – just ventilation and cooling.

Electricity: 6 kWp solar PV system awaiting installation, with electric car on order too.

Green materials: 50 per cent GGBS in the concrete blocks and raft, and first floor construction cellulose.

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BREATH OF LIFE ENERPHIT UPGRADE REJUVENATES RATHGAR REDBRICK The skilful deep retrofit of a red-brick semi on the south side of Dublin has brought an old property into the 21st century in terms of energy performance and living space, while carefully upgrading its century-old façade with breathable materials.

By John Hearne

IN BRIEF Building: Deep retrofit & extension of 1920s semi-d Method: External insulation, breathable internal insulation, single leaf thermal block extension Location: Rathgar, Dublin Standard: Enerphit (certification pending) Heating cost: €24/month* *Space heating use only, modelled based on measured energy use. See ‘In detail’ panel for more information.

€24 per month

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CASE STUDY

A

Brendan grew up in the house, and was now returning to live there with his own family.

Photos: Abdone.com

year after their house in South County Dublin had been retrofitted to the Enerphit standard, owners Brendan and Geraldine decided to apply for certification to the Passive House Institute.

But to be certified as having met the Enerphit standard, new airtightness tests would have to be done.

“Going back to do airtightness tests a year after completion isn’t ideal,” says architect and passive house designer, Mel Reynolds.

“Normally you’d try and do your final test as close to when you complete as possible because buildings settle, doors warp, seals come loose... There was one sliding door that was in constant use. I was sure that there would be problems there.”

It’s a measure of just how well executed the project was that the blower-door test registered 0.9 air changes per hour – inside the Enerphit standard of 1.0 – on the first go.

Neville Road in Rathgar is a 1920s development of red-brick semi-detached homes, and this is the last house in the row. Brendan grew up in the house, and was now returning to live there with his own family.

Prior to the refurb, there had been a dilapidated single-storey lean-to extension to the side. This was set to be demolished and replaced with a single-storey rear extension and a two-storey side extension. Though it had been lived in continually, by the time the project began in 2020, the house felt a little unloved. Both wiring and plumbing needed extensive work, and the windows and doors were in need of replacement, while the layout of the rooms belonged to

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another time.

“It was always going to be a deep retrofit,” says Reynolds. He notes too that the initial design specified a larger extension, but that before finalising the layout, he and the clients took a closer look at the family’s space requirements. “I’d recommend that anyone considering an extension, first look at the space that you use every day.”

It can be a very revealing exercise because it invariably uncovers areas that are either being under used or not used at all. “A lot of us think, ‘I don’t have enough space, I need to extend the house,’ but hang on for a minute. Are you using all the space you’ve got well? Are there any spaces that you don’t use? Maximise what you have before looking at extending.”

The family wanted to retain as many of the old features of the house as possible, while at the same time creating spaces more attuned to how we live today: open plan living areas, additional bathrooms and bedrooms upstairs. The brief also included a self-contained studio apartment/office space, to cater for the needs of family members as they change.

“The extension is almost invisible from the outside,” says Reynolds, “the front façade is very low impact, very understated, but when you walk in the front door to the central area, all of a sudden you have a double height, cathedral space with an overhead walkway linking with the master bedroom.”

Downstairs, the open plan kitchen/living room connects directly to the garden via a large sliding door. “In going from the mas-

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Maximise what you have before looking at extending.

ter bedroom to the kitchen, you experience seventy per cent of your house; you’re not simply being threaded through it, while the double height brings the whole lot together.”

The story of the Neville Road deep retrofit really begins with an earlier Mel Reynolds project, the country’s first passive house ‘plus’ project, which was Reynolds’s own house at Cove Mews in Sandycove, a project featured in issue 35 of Passive House Plus.

While working on this project, Reynolds was struck by how well several of the building solutions he implemented there would work on a refurb.

Airtightness is always a challenge when you’re retrofitting, but two things served to make the process surprisingly smooth on Neville Road. The first was that the builder on Cove Mews – Sean Regan – also won the tender here, and so was equally familiar with the solutions deployed in the earlier project. The second was one of those solutions: Blowerproof liquid airtight membrane. This is a BBA certified product with Class C fire rating which has been used in Europe for some time. It’s a paint-on product.

In the new parts of the house, there was no need to batten out the walls or attach a screw-fixed plasterboard. Instead, the build team used dot and dab plasterboard, while in the older part of the house, the liquid membrane was simply applied to the existing plasterwork.

“It didn’t take Sean any more than a week to get to a preliminary airtightness level of 0.9. Because he had done Cove Mews, airtightness here was a doddle. No need for all the tapes and things we used to use in junctions and in floors, which were really laborious. With this, you’re simply spraying it on.

It’s perfect... The lesson for any contractor with these onerous, difficult-to-achieve standards is that when you’ve done it once, that’s it, it’s easy.”

While existing plasterwork was retained inside the house, the design team decided to replace the suspended timber floor with an insulated concrete slab featuring 50 per cent Ecocem GGBS. Walls are externally insulated where possible. The red-brick front façade was of course retained, and faced internally with a 60 mm Calsitherm board. Calsitherm is a breathable calcium silicate board, made from a mix of lime and sand, which is capable of regulating dampness in walls by absorbing

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it and then allowing it to evaporate and dry out. The design team conducted condensation risk analysis to determine the optimum thickness of the interior board.

“When you have a protected façade or brick – as in this case – you insulate as much as you safely can and then compensate on other areas. That’s what we did here. In the end, our provisional rating was A1.

Brendan mentioned that a scheme of very expensive new houses had just been launched not too far away from this one, and they were A2 rated. So, this 1920s build was delivering a better performance than those lavish new homes.”

The original house relied on infiltration

and opening windows for ventilation. The refurbished house uses Lunos decentralised heat recovery ventilation units from Partel, a technology which Reynolds came across before but hadn’t found the right opportunity to deploy.

“Centralised mechanical heat recovery ventilation is great, you have ducts, you have a single unit and your efficiency is very high, but in existing buildings, fitting a centralised system is a real challenge because you don’t have the space for ducts, you don’t have the voids, plus you might have to retain ceiling details like cornicing.”

By contrast, Reynolds says decentralised systems are ideal in retrofits. You install

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NEVILLE ROAD

Going back to do airtightness tests a year after completion isn’t ideal.

vents, bring power to them and each is commissioned individually.

“All they need is power, you don’t have any interruption to your ceilings or floors and the cost to run them comes to a total – across the whole house – of between €10 and €12 per year. It’s a brilliant concept for existing buildings, particularly when you want to get your airtightness down to passive levels.”

He continues: “The back elevation of the house has a unified, modern look, without fascia boards, so that internal roof insulation meets external wall insulation in one continuous layer, thereby eliminating thermal bridges. It’s a very elegant detail architec-

turally but it also has the added benefit of delivering high performance.”

In the year up to the beginning of the project, the house had been occupied by two people – Brendan & Geraldine’s son and partner. When the retrofit was completed in late 2020, Brendan, Geraldine and their adult son Thomas moved in, with the occupancy doubling the following summer, when Brendan and Geraldine’s son John moved in with his partner and their baby.

During the two-person occupancy pre-retrofit, total energy used over a twelve-month period came in at 3,151 kWh of electricity and 11,103 kWh of gas. From May 2021

to May 2022 – a period including six occupants from June to January – total energy use came to 8,551 kWh. But how would the house fare with half the number of occupants, as current? Cue energy modelling expert Tim Cooper, who devised a way to deduct the impact of increased occupancy, and account for the house drying out and the homeowners learning to use the new systems in the house – factors which substantially affected the building’s energy use.

Cooper developed an energy performance model for the house, taking account of the extra demand placed on the house for showering, space heating, cooking, refrigeration, washing and other appliance use – and taking account of the rated power use of the actual appliances in the house. The usage assumptions were corroborated by Brendan.

Space heating increases were assumed from the house drying out and the occupants learning how to use the new heating system.

The net result: total energy use reduced from an unadjusted total of 8,551 to 6,290 kWh/yr. Of this, 1,452 kWh was attributed

WANT TO KNOW MORE? The digital version of this magazine includes access to exclusive galleries of architectural drawings.

The digital magazine is available to subscribers on passivehouseplus.ie & passivehouseplus.co.uk

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to space heating demand, at a cost of less than €24 per month based on current electricity prices.

With the risk of rocketing electricity prices obscuring some of the energy savings accruing from the refurb, the clients decided to install PV panels after the project had been completed. Planning permission was granted for panels on the back of the house, but analysis by Tim Cooper - who is also arguably Ireland’s leading expert on PV – revealed that chimney overshadowing would be an issue. So instead, the design team created a carport with a butterfly roof, and eight panels are due to be installed in the coming weeks.

Cooper predicts that once the PV array is in place - and using a dynamic model to project the output of the array on a granular level throughout the year, against his granular model of the building’s energy use – the array will reduce grid energy use to 4,181 kWh/yr. This is based on the planned installation of an eight panel (2.96 kWp) PV array. Cooper’s projections – based on the measured output of a similar array on a local project – to be 2,447 kWh/yr, including 1,427 kWh of useful energy, and 1,021 kWh to be exported to the grid. Cooper projects that the useful energy generated by the array will knock over €330 off the house’s electricity bill.

Like so many houses of its vintage, Neville Road was draughty and hard to heat, which is part of the reason why the clients specified underfloor heating throughout the refurb.

When the team ran the design through the Passive House Planning Package (PHPP) software however, it suggested that underfloor heating was surplus to requirements. It was retained – just in case – but two winters in, it’s hardly been used.

Like many designers before him, Reynolds pays tribute to PHPP as a design tool. On a different project, the software suggested that the radiators that had been specified were unnecessary upstairs.

“Again, just in case, we put in flow and return for the rads, but left the rads themselves out. That saved the clients about €3,000. If they wanted them later, they could put them in easily… And last year, we had supply chain problems, but if one insulation is unavailable, you can put the spec of a potential replacement into the software and it will tell you if it’s going to work or not.”

Rainwater harvesting should be in all retrofits and new builds.

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CASE STUDY

Hidden beneath the back garden of the Neville Road Enerphit, there’s a 5,000-litre rainwater harvesting tank which is plumbed to the WCs. This makes the house a lot more self-sufficient, and guards against the impact of water charges if and when they return.

And as Reynolds points out, the cost of installing rainwater harvesting during refurb is far cheaper than doing so after the fact.

“I think rainwater harvesting is something that should be in all retrofits and all new builds, and should be incentivised. It just makes no sense to use potable water that we have already treated to flush toilets.

So don’t buy an expensive sofa. Get one in Ikea and install a rainwater harvesting system instead.”

1 Construction underway of the two-storey side extension constructed of Mannok Aircrete blocks; 2 delivery of the large glass patio door with pre-fitted brackets for the new rear extension; 3 Internorm triple glazed aluminium-clad oak units sitting proud of the blockwork to keep continuity with the external insulation layer; 4 carefully applied Siga airtight tape seals the joist ends and stud walls to the Mannok blocks; 5 wetroom tanking to wall of master bedroom ensuite at first floor level, pre tiling; 6 Blowerproof to inner surface of Mannok block walls with surface-mounted slimline boxes and conduits – no chasing required before dab and slab applied as internal finish; 7 60mm Calsitherm board applied to existing solid brick front bay wall with Blowerproof repairs behind (airtight layer on inner surface of existing wall) and Calsitherm applied to reveals; 8 Siga Majpall airtight membrane to double height ceiling.

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THE STREET

CASE STUDY

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SELECTED PROJECT DETAILS

Architect & passive house design: Mel Reynolds Main contractor: Sean Regan Ltd Quantity surveyor: Damian Bowers & Associates Services engineer: Mike Kelly & Associates Structural engineer: Carraig Consultants Health & safety: Safety Solutions Passive house certification & thermal bridge analysis: Earth Cycle Technologies Renewable energy consultant: Tim Cooper Conservation Engineering Consultant Roofing: KD Roofing Mechanical contractor: Mountain Lodge Mechanical Services Electrical contractor: Thomas Kenny & Co Heat pump: Heat Merchants Decentralised MVHR: Partel Ironmongery: Ecco Architectural Hardware Solar PV consultant: Tim Cooper Conservation Engineering Consultant Underfloor heating: Unipipe Windows & doors: Internorm, via Eco Window Concepts Rooflights: Velux, via Tradecraft Blockwork: Mannok Rigid insulations: Kingspan Mineral wool: Isover Calcium silicate board: Ecological Building Systems External render: Baumit Airtightness tapes/membranes: SIGA Liquid airtight membrane: Blowerproof Ireland Flat roofing: Moy Materials Thermal breaks: Compacfoam, via Partel Concrete containing 50 per cent Ecocem GGBS: Kilsaran FSC certified timber: Glennons BER: SC Airtightness & Ventilation Rainwater harvesting: Wastewater Solutions Metal fabrication: Dunfab Engineering Sanitaryware: Bath House Kitchens: Timbercraft

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| www.partel.co.uk

Fabric First Approach Incentivised Under New Part L & O Regulations The hotly awaited changes to the Building Regulations Part L will come into effect from 15th June, alongside the newly introduced Part O, which covers overheating risk in residential buildings.

The changes present the biggest shake-up to the Part L regulation since the introduction of mandatory energy performance assessments in 2006.

Combined with the new Part O Overheating document, the two codes will encourage design teams to pay greater scrutiny to operational energy demand and summertime overheating risks, and the interplay between the two dynamics.

Headline changes to the Part L code include the introduction of a mandatory primary energy target and revisions to fuel carbon factors, particularly that of grid electricity. Grid electricity now enjoys a carbon factor some 2.6 times lower than the former Part L code, and lower than natural gas. As a consequence, electrical modes of space and water heating will be substantially incentivised under the new code.

The new electricity carbon factors will be based on monthly averages, rather than the old annualised average.

The carbon factor is higher during the winter; a dynamic that better reflects the characteristics of the electricity grid. In so doing, a fabric first approach should be better incentivised under the new code, with reductions in wintertime energy demand having a greater impact on assessment outcomes than was previously the case. We can, therefore, expect to see thermal insulation, airtightness, and low psi-values playing a more prominent role in Part L outcomes than was previously the case. Inversely, the carbon savings available via a typical solar PV will be around 4.5 times lower than those occurring under the current Part L code, meaning that solar PV will no longer offer a ‘get-out-of-jail’ option for underperforming buildings.

Indeed, the Part L ‘notional building’ will account for a PV array by default. Greater focus will therefore be placed on design teams to model Part L compliance risks right from the concept stage, with fewer options to rectify underperformance during the construction phase.

IES’ expert level 5 assessors and VE software can help design teams investigate their architectural concepts in line with the new regulations. Contact details opposite.

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Part O, which accounts for overheating risks, will be introduced alongside Part L. Part O applies to dwellings, institutions, or any other building containing one or more rooms for residential purposes, other than a room in a hotel. The new code adopts the well-established CIBSE TM59 thermal comfort metric as one route to compliance.

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CASE STUDY

NEVILLE ROAD

IN DETAIL Building type: 167.4 m2 semi-detached house from 1928. Works included 46.7 m2 part demolition of existing building and single-storey lean-to side garage, Enerphit refurbishment with new single-storey rear extension and two-storey side extension of 67.9 m2. Total completed net floor area 188.6 m2.

Location: Rathgar, Dublin 6 Budget: N/A Completion date: October 2020 Enerphit certification: Pending BER (before): F BER (after): A1 (provisional) Heat load: 13 W/m2 Primary energy demand (PHPP): 45 kWh/m2/yr Primary energy renewable (PHPP): 25 kWh/m2/yr Heat loss form factor (PHPP): 2.79 Overheating (PHPP): 1 per cent (of hours above 25 C) Number of occupants: 3 Measured energy consumption Before: 3,151 kWh (electricity) and 11,103 kWh (gas) over 12 months pre-retrofit, with two occupants in the house. Total: 14,254 kWh After: (May 2021-May 2022) 8,551 kWh total consumption (all-electric) over one year post-retrofit, but with three occupants for four months, and six occupants for eight months. An energy model from Tim Cooper produced an adjusted figure for three occupants, allowing for the house drying out and homeowner learning to use the building, of 6,290 kWh/yr. This includes 1,452 kWh for space heating. Passive House Plus took the cheapest tariff available on Bonkers. ie as of 3 July 2022 of 19.69c (based on smart meter, urban connection, without night meter), meaning the portion of energy use for space heating comes in at €286/yr, or under €24 per month. Standing charges were excluded from this calculation, as they are incurred at the same rate merely by having an electricity connection.

In fact, the decision to switch from gas to electricity for heating avoided incurring a second standing charge - ranging from €104 to €187/year, depending on the supplier. This reduction was not

factored into these calculations.

Airtightness (at 50 Pascals): 0.9 air changes per hour.

Floor Before: Uninsulated timber ventilated floor in main section of house with solid concrete uninsulated slab to original side garage. U-value: 1.85-3.48 W/m2K After: 150 mm thick 50 per cent GGBS RC slab insulated with 270 mm Kingspan K3 insulation.

U-value: 0.073 W/m2K Walls Before: 300 mm solid masonry walls. U-value: 0.65-0.80 W/m2K After (generally): Acrylic external render on 140 mm Kingspan EWB insulation, on 300 mm existing masonry wall with 15 mm existing render, with Blowerproof airtightness paint (as required), with 12.5 mm plaster on 15 mm dabs internally. U-value: 0.12 W/m2K After (brickwork front elevation): Existing brick-faced 300 mm masonry wall with 15 mm existing render, with Blowerproof airtightness paint (as required), with 60 mm Calsitherm board skimmed internally. U-value: 0.585 W/m2K Roof Before: Sloped with mineral wool insulation. Roof slates to sloped areas and torch-on-felt to flat roof areas externally. 75 mm mineral wool insulation on the flat between roof joists and a combination of suspended ceiling tiles or plasterboard ceiling internally. U-value: 0.47 W/m2K After: Min 50 mm ventilated space retained between underside of existing slates and top of 100 mm Kingspan K7 Thermaroof insulation friction-fitted between rafters with counter-battens, and 100 mm Kingspan Thermaroof insulation to underside (200 mm total), with Siga vapour membrane and 13 mm plasterboard finish internally. U-value: 0.134 W/m2K Extension new walls: Acrylic external render to 140 mm Kingspan EWB insulation, to 215 mm Quinn Lite B5 blocks, Blowerproof liquid airtight membrane, 12.5 mm plaster on 15 mm dabs internally. U-value: 0.12 W/m2K Extension flat roof: Paralon NT4 2-ply roofing

membrane on 120 mm Paratorch insulated board, on 18 mm OSB on timber joists, with 210 mm infill Kingspan K7 insulation and 15-90 mm Isover Metac insulation, on 15 mm OSB board underside, with 25 mm service cavity and 12.5 mm plasterboard internally. U-value: 0.10 W/m2K Windows & doors Before: Single glazed timber windows and doors.

Overall approximate U-value: 3.50 W/m2K After: Internorm triple glazed aluminium-clad oak windows, with argon filling and an overall U-value of 0.73 W/m2K; G value 0.6 Roof windows: Velux triple glazed window No 68. Centre pivot, electrically operated pine finish internally. Overall U-value: 1.1 W/m2K Attic hatch: Wellhöfer Passive House Institute certified airtight hatch Heating system Before: 20-year old gas boiler & radiators throughout.

After: Panasonic Aquarea air source heat pump with Harp database registered COP of 4.74, delivering to underfloor heating throughout, fitted with integral hot water cylinder.

Ventilation Before: No ventilation system. Reliant on infiltration, chimney and opening of windows for air changes.

After: Lunos decentralised E260 and Ego ventilation units. E260 has maximum efficiency of 96 per cent and 88 per cent to EN13141-8. PHI adjusted efficiency for this project is 75 per cent, with specific power consumption = 0.11 W/m3/h.

E260 is the only decentralised fan with S1 wind class protection, and costs from €10 to €20 per annum to operate the system including filters.

Water: FLine Diver 5,000 litre rainwater harvesting tank supplying all irrigation and WCs. All sanitary fittings are low-flow 9 litres per min.

Green materials: A 50 per cent GGBS cement used in all in situ-concrete, aerated blockwork throughout with FSC certified timber in all areas.

All ground surfaces are permeable.

Electricity: Yet to be installed. Plan is for 8 x 340 W peak PV modules, prioritised over heat pump for generating hot water.

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WE BUILD ECO

INSIGHT

Flat pack on track

Partnership promises scalable ecological timber builds What do you get if you cross a quantum physicist, a forensic accountant, a merchant, an engineer and a software-whizz-kid architect? A terrible punchline presumably. But as Jeff Colley discovered on a trip to Sussex, you get something not to be laughed at: a collaborative approach that may be about to unlock a scalable, highly sustainable, circular economy-proof, flat pack build approach.

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postcard-picture farm in a national park may not be the backdrop you’d expect for cutting edge innovation in sustainable building, but in the case of one exciting new venture, the agrarian focus on growing from nature seems particularly apposite. Because hidden in the sunny, bucolic landscape of the South Downs National Park in West Sussex, a potentially revolutionary approach to house building has emerged under the banner We Build Eco – which effectively offers designers, builders and clients the ability to borrow a factory and skilled team to convert their building designs into a leading edge timber frame flat pack system. Passive House Plus got sneak preview access to the new venture prior to its full launch.

Chloe Hayward and Antoine Costantini have been constructing low energy buildings under the name of Kithurst Homes since 2006, experimenting with a number of build systems ranging from insulating concrete formwork to timber frame. An unassuming

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man who is disinclined to talk about himself, Costantini’s background is too insightful to ignore. Having worked on passive house projects as part of Plate-forme Maison Passiv in Belgium and Germany, Costantini has a background in quantum physics, the study of matter and energy at the most fundamental level, which aims to uncover the properties and behaviours of the very building blocks of nature. He took this spirit of scientific discovery into his construction, seeking approaches which delivered scientifically robust approaches to energy performance, comfort and durability, while minimising environmental impacts. The more he and Hayward researched, the more they were drawn to approaches founded on timber – albeit where used sparingly.

“Building out of logs doesn’t make sense,” says Costantini. “We don’t have the resource and that resource is not for ever. At one point we won’t have enough timber to build all in timber.” Costantini posits the use of engineered

timber as a solution. “If I use an I-joist, I can use 40 to 60 per cent less timber. We can build more for the same amount of tree.”

Hayward’s background in forensic accountancy provided a useful corrective to identify approaches which stacked up commercially.

They eventually settled on a panel system whose name riffs off structural insulated panels (SIPs), albeit with more ecological materials – naturally insulated panel products (NIPPs), which Costantini describes as “our core.”

“I designed the NIPPs as a simple system which is always I-joist core,” he says, a system which consists of wood fibre insulated panels with I-joists of variable thicknesses depending on the desired insulation level, and 60 mm of semi-rigid wood fibre insulation to the external to eliminate thermal bridging. “We realised that was the best bang for the buck.”

Having elected for an I-beam based structure using wood fibre insulation, it was no surprise that the pair ended up running into Will Kirkman of Ecomerchant, whose

INSIGHT

WE BUILD ECO

(above) Chloe Hayward emphasises that while it is possible to make insulated panels in the factory, We Build Eco would rather charge less money and send flat packs out to reduce transport costs and emissions, and to support local economies..

broad range of green building materials includes wood fibre insulation and I-joists from German natural materials giant Steico.

The We Build Eco collaboration also includes that rarest of things – a structural engineer with real expertise in sustainable building, in the form of Beth Williams of Build Collective. The collaboration also extends to a relationship with Charlie Luxton Design, who have made significant contributions in manipulating design software to suit the system to convert 2D drawings into a 3D house complete with a fully detailed We Build Eco superstructure.

“The whole thing about We Build Eco is that it identifies a methodology and production capacity to build,” says Will Kirkman.

“In its simplest form: you send us your simplest drawings, we convert them into a We Build Eco house – an I-joist house – which you then get delivered as a kit. You can’t get simpler than that.”

One of the keys to unlocking this simplicity is technology. Kithurst invested in a high tech Hundegger saw to cut the elements for timber frame buildings quickly and with unerring precision. And a major part of the saw’s significance comes in the software which controls it – and the ability to interface with 3D building design software.

In practical terms, the process typically runs

like this: an architect provides 2D drawings for a building, irrespective of what construction method was intended. Costantini uses specialist 3D wood manufacturing software Cadwork, which he has populated with a library of wall, to trace over the drawing. “I can take any drawing – DWG, PDF – put it in 2D and trace over it.” Utilising the team’s expertise in timber engineering, We Build Eco have discovered a way to translate the drawings into an engineered output and file suitable for use by the cutting equipment. “So I can have all the joists, all the screws, the insulation – everything. That works extremely well.” If the architect already has 3D BIM files, Costantini converts it into Cadwork. “The beauty of that software is it talks the update to my machine.

So instead of doing a cut list by hand from an Excel spreadsheet and filling up a BVX [Hundegger] machine file, this thing in two and a half minutes flat will transform it to a BVX file. It goes directly to the Hundegger, and it’s cut, labelled and marked.”

Costantini showed a demonstration of the system to a rapt audience of sustainability-focused construction professionals at a soft launch in June, the saw balletically pivoting to cut timber element after timber element quickly and precisely – to tolerances of between 0.5 and 1.5 mm, depending on the angle the timber is being cut at.

“We do spot checks all the time. To check it’s always in that 1.5 mm tolerance”, says Costantini. If it’s out by more than 1.5 mm, the machine is stopped and a spot check is done to see if something is wrong with the machine or the timber. In the truss industry, roof trusses may be made to 10 mm to 15 mm tolerances, but as a batten is placed on top, it tends not to matter. But part of what marks out We Build Eco’s offering as different is an obsessive attention to detail.

Will Kirkman points out another benefit of an approach which provides a much more rounded design before a tool has been picked up on site: buildability. “The other advantage of this translation process is that it doesn’t allow an architect to design in undeliverable connections and junctions,” he says.

According to Costantini, while most architects are still working in 2D, converting the plans to 3D can provide key insight to prevent problems on site – with one recent project near the factory fresh in his mind.

“We got a valley rafter, and it was really tight,” he says. “In 2D you don’t see the space you’ve got under, and it did not work. On a flat plan it worked extremely well. As I always say, Autocad is beautiful. I can fit a pregnant elephant in a shoebox. In reality, it’s always a bit different and harder. I did it in 3D, I talked to the architect, who came in here, and

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WE BUILD ECO

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Located on a farm in a national park, the factory makes use of extensive PV arrays to reduce manufacturing emissions, such as from the electric Hubtex forklift.

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INSIGHT

we went through it and she realised how bad it was and in 3D we found a way to do it.”

“We’ve been asked by architects to build houses where you have a floor plan, an elevation and a section, and nothing works. You’ve got a wafer thin floor with an enormous beam in it, because there’s no integrated design. They don’t talk to each other. The builder gets a bad rep. but actually they’ve saved the backsides of many architects, because they make it work on site.”

When the soft launch event in June was winding down, there was a chance encounter with one of Kithurst’s clients, Alan Brown, who had popped into the yard to pick up some rolls of insulation. A bank fitting contractor of some 40 years vintage, Brown prefaced his words by saying “I’m not eco but,” before launching into gushing praise of a system he was using to build his own house. “You get the sole plate down, you make sure it's all plumb, and that’s it,” he said, still reeling from the fact the system, went up so seamlessly – and with nothing to put in the skip. As Will Kirkman points out, clients learning about this precision are starting to demand more.

“Antoine’s got another customer who was a bit miffed that his roof – with a three way roof with a valley – was 3.5 mm out,” he says.

A novel aspect of We Build Eco is the decision to focus on providing flat pack build systems rather than pre-fabricated

panels wherever possible. Chloe Hayward lists two scenarios for how this might work on a housing scheme. The flat packs can be transported to site, with the structures then built on site. Or the developer could find a local warehouse, set it up and they build the cassettes there, transport it down the road and crane it all in. “You have the choice of either sending it direct to site or to a hub effectively where you have people indoors,” she says. “You might decide: ‘This build is going to be affected by the weather, I’ve got loads of warehousing space empty. I’m trying to create a local project, involve local builders and maybe get some apprentices involved – and maybe it’s just easier to manage in a big warehouse and organise it that way.’”

Hayward doesn’t rule out making the panels in Kithurst’s factory, but only as a last resort.

“We could do it here but actually we’d rather do the volume, send the flat packs out, take less money from everyone and make the economy more of a local economy.”

Part of Hayward’s thinking is about transport. “If we create a flat pack and send it out, it means less transportation coming in and out of here because I’ve got one lorry going out as opposed to maybe six or seven.

Once they’re made into a panel they take a lot more room and you need a lot more transport. And transport costs are high – it can be £700 for an arctic not that far away.

WE BUILD ECO

You start adding up the number of arctics you’ve got and it adds up quickly. Plus they have to crane everything. So if they’ve got everything locally, it’s easier than waiting for each delivery.”

By way of example, Hayward mentions a flat pack Kithurst supplied earlier that week for passive house build system supplier PH15.

All the I-joists and LVL for the 200 m2 house went out on one arctic lorry. “It wasn’t even full actually,” she says.

It’s no surprise that this rounded sustainability consideration extends to other aspects of the business, including how the flat packs are sent out. “We don’t repackage what we’ve cut with plastic." says Hayward. "We send everything out with metal strapping on bearers. And it’s up to the customer to put a tarp on it or something and keep it dry.”

What’s more the build system has been designed with the end of life in mind too, with Costantini saying the whole system is intended to be dismantlable and recyclable.

“My idea was that every component is recyclable or compostable.”

This interest in circularity was also another reason why Costantini was drawn to Steico.

“I work with Steico for a reason,” he says.

They use everything. They shred wood to make insulation. They make LVL, I-joists and pallets made from the centre. Nothing is wasted.”

(below) 2D drawings are converted into 3D buildings complete with a fully detailed We Build Eco superstructure.

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WE BUILD ECO

INSIGHT

(above) Information from the 3D drawings is relayed to the software for operating the Hundegger saw, so that timber elements can be cut precisely to size. The 5-axis saw unit can be pivoted through 360° and at the same time tilted by 90°.

Will Kirkman emphasises another benefit of Steico’s insulation which may start to gain currency in light of the increasing risk of heat waves: phase shift, or the time between the highest temperature occurring on the outside of a component and the highest temperature on its inside. Recent analysis by Steico UK technical director Martin Twamley showed that build-ups with identical U-values could see phase shift vary from roughly six and a half hours to 14 hours, simply by changing the materials used, such as different sarking boards and insulation. “The whole point is there are areas where natural insulation materials just perform better than synthetic ones, and so that should be the natural default choice,” says Kirkman. “Certainly with any kind of room in the roof – any living space adjacent to the roof – any walls with lightweight construction – the natural insulation material is the one to use. You just don’t want to say to people it’s natural. You want to say to them it is a really good performing building. It outperforms building regs for the same price as one that only complies.”

The system is notable in the conscious decision to eschew plastic. It’s safe to say Costantini is not a fan of the use of plastics or oil-based products in buildings, be it in the form of insulation, windows or gutters etc. He cites a 2019 study which indicated people may be consuming five grams of microplastics per week – equivalent to a credit card. “Using plastic is a deliberate act as part of a systematic campaign which has caused human suffering on a large scale,” he says, There is an openness and generosity of spirit in the thinking behind We Build Eco – in the willingness to share their entire system and processes to all and sundry – an openness which is admirable and necessary, given the need for the whole industry to rapidly shift to building physics-based sustainable building methods like this.

“If you hold your little secret in your hand and you don’t want to share it it’s not going to work, because only a few people will have that lovely golden goose egg, and that’s it,” says Costantini. “What I want is: we don’t talk about natural material anymore in construction because it’s so normal we don’t have to. For the moment, we talk about it because it’s not the norm, and that’s my little war on building, to get people using natural materials. It’s not tricky to use them, it’s no different from other stuff.”

What is the We Build Eco system?

Kirkman is at pains to point out that the We Build Eco system shouldn’t be conceived of as a proprietary system in the conventional sense. “The issue we see in the marketplace – the bit people struggle to do is to get someone to build what they want to their designs. This is effectively a factory for rent that builds an I-joist system. Once the engineering is agreed, the process becomes about making their product for them.”

Kirkman foresees developers, builders – even timber framers who are selling beyond their capacity – using We Build Eco on their projects, and even taking their clients to visit the factory. “We are really just skilled employees who are not on your payroll,” he says.

The full build up from inside to out includes an airtight layer (either an airtight racking board such as Durelis Vapourblock or – more typically for roof panels – a paper membrane), an I-beam – available, depending on how much insulation is required, in widths of 160, 200, 240, 300, 360 or a whopping 400 mm . The void is then filled – typically with Steico Zell blown wood fibre insulation, though Steico Flex is also possible, as indeed is blown cellulose insulation.

In the case of walls, the system will require a membrane, but the roof may not. “There will normally be an internal membrane required in the roof – either Majrex, Intello Plus or Constivap,” says Kirkman. “The Vapourblock will do the job in the walls. And that’s where We Build Eco stop.” The partnership has stopped short of appointing a membrane partner, to give customers the flexibility to work with a membrane they’re comfortable with. “I don’t think we’d bring in a membrane partner for that reason,” says Hayward. “Because we all have different preferences about applications.“ The system is finished to the external with 25 to 50 mm battens, depending on the cladding type.

The partners are also open to working with different window suppliers.

“This isn’t the kind of collaborative attempt where everybody’s looking to make a bit of money on everything,” says Kirkman. “It’s the core service, the core provision is costed out with everybody with a margin in it. We’re quite happy with that thank you very much.”

Brexit has made it harder to export the system for tax reasons, though Hayward explains that they are set up to deliver in Ireland too, albeit without supplying the insulation.

ph+ | we build eco insight | 75

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INSIGHT

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WE BUILD ECO

1 Industry professional attendees at the We Build Eco open day were invited to get their hands dirty and make NIPPs for themselves; 2 Steico UK technical director Martin Twamley with product and business development manager Daniel Brown pitching in; 3 wood fibre board being screwed to the outer face of the panels; 4 in a rare practical moment, Passive House Plus editor Jeff Colley fixing a Vapourblock airtight board to the inner face of a NIPP; 5 & 6 Costantini pumped Steico Zell wood fibre insulation into a perspex-fronted NIPP and removes the casing to measure the density of the insulation using an X-Floc NW100 density testing set.

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ED BEGLEY JR

INSIGHT

Ed Begley Jr: “A lot of people want to do something. You’ve got to give them choices that resonate with them.”

Actor Ed Begley Junior is one of America’s best-known and longest-standing environmental activists. Fresh from lighting up our screens in the final season of Better Call Saul, Begley spoke to Passive House Plus about the roots of his activism, and what drives him on in the face of such adversity.

Words by Jeff Colley

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d Begley Junior’s environmental roots are inextricably linked to his past – including his lived experience as a young man growing up in Los Angeles, and the inherited traits of his Irish forebears.

LA at the time was choking so badly on smog from the city’s slavish devotion to the internal combustion engine that it earned the nickname Smell-A. “I grew up in smoggy LA. And that pollution was horrible, it just seared my lungs every day,” he told Passive House Plus, speaking from his LEED Platinum certified eco house in LA’s Studio City district.

For Begley, the palpable sense of wrongness in having to breathe in poisoned air struck a nerve. This outrage, combines with ways of living passed down from his Irish grandparents awoke something in the young actor.

His grandfather and grandmother hailed from the Kerry towns of Killorglin and Killarney respectively, hardwired with the profound sense of frugality and resourcefulness that typified the generations who came up before the advent of cheap energy and the rise of throwaway consumerism.

“It all came from my Irish grandparents, it really did,” Begley says. Having taken the boat to America in the late 1890s, the couple settled in Hartford, Connecticut, where his grandfather, a hod carrier, plied his trade. Begley’s father, Ed Begley Senior took a different path, rising to become a celebrated, Oscar-winning character actor,

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with film credits that include 12 Angry Men. But Begley Sr never lost his Irish parents’ thriftiness, and he passed it onto his son.

“I always just revered that part of my past, that frugality,” he says. “My dad was a great influence on me, he was. We would save string and tin foil and turn off the lights and turn off the water. We were never wasteful. I got all that from my dad.”

A longstanding vegan and animal rights activist, Begley’s Irish ancestors’ resourcefulness and connection to the environment may have manifested itself more violently.

“There's a book somebody sent me called Kerry man,” he says. “Apparently, there's some Kerry people related to me who were quite brave. They would swim into the chilly waters of the Atlantic with somebody in a boat nearby with a rope around them so they didn't drift away, and they would club a seal, and get some seal meat or seal oil for lamps.” Unperturbed by tales of the gregariousness of his ancestors’ proto-environmentalism, Begley, who first visited Ireland with his father in 1966, has notions of returning.

“I'd like to get back again while I'm still alive,” he says. I tell him it’s preferable to make the trip when you’re alive. “It’s much better, that I’m told,” he says.

ence, he had an environmental epiphany.

But less than a week later, personal tragedy struck. Begley’s father suffered a heart attack and died suddenly and unexpectedly. Heartbroken though Begley must have been – he still talks fondly of his “wonderful dad” – Begley nonetheless threw himself into his budding environmentalism, in spite of his life being upended by the tragedy.

With his limited funds, he even bought an early electric vehicle – a $950 Taylor-Dunn which Begley describes as a “golf cart with a windshield wiper and horn,” and a top speed of 32 km/h. He quickly retired it for a vehicle with more horsepower: a bicycle.

“I wanted solar panels on my house and a nice electric car that had some range to it.

And those things were very much unavailable to me. After my dad passed in 1970, I was a broke, struggling actor,” he says. “So, I got to do just what I could afford, you know – recycling, composting, vinegar and water instead of harsh cleansers, baking soda instead of [American household cleaning product] Comet. All the stuff that I could do that was very cheap, I did.” Years later, having saved money as a consequence of “picking the low hanging fruit”, Begley invested in making the first home he owned

In 1970 Begley bought an early electric vehicle which he describes as a “golf cart with a windshield wiper and horn.

With a nascent environmental movement beginning to gestate in the 1960s, Begley was smack bang in the middle of an event that many people regard to be the birth of the green movement: the first Earth Day, in April 1970. Hearing talk of air and water pollution that chimed with his own experi-

energy efficient.

In 1982 Begley landed the role that made him famous, playing Dr Victor Ehrlich in ground-breaking medical drama St Elsewhere, for which he received six consecutive Emmy nominations and a Golden Globe nomination. With his

INSIGHT

newfound success he bought a house and started investing more meaningfully in energy efficiency and renewables – which at the time came with a real cost premium.

“15 years after I got involved in 1970, I could finally afford solar,” he says. “Not solar electric. That was still out of range for me pricewise and it was hard to get good solar electric panels, but I got solar hot water in ‘85. And I bought a wind turbine in ‘85 as part of a wind farm investment. And all that stuff worked and saved me money.”

Buoyed by the savings his decisions were delivering, Begley kept going, investing in a range of green measures in his 147 m2 home – a veritable micro house by American standards, let alone for someone in show business. This included tried-and-tested energy and water saving measures ranging from insulation, to solar to the – shall we say – experimental: a pedal-powered toaster.

In 2000 Begley married Rachelle Carson, and the couple starred in a green living reality-TV show Living with Ed from 2007 to 2010, which pitted Ed’s efforts to minimise the family’s environmental impacts against Carson’s more regular folk-friendly views, in a case that was less good cop/bad cop, more eco-fundamentalist cop/bemused long suffering cop.

Over time, with the success of the show and Begley continuing to land work in high profile, Hollywood fare – ranging from Christopher Guest’s mockumentaries to Six Feet Under, Arrested Development, Pineapple Express and countless others – Carson convinced Begley that a bigger

house with more storage and more than one bathroom to share with their then teenage daughter was in order. “I always lived in smaller and very energy efficient houses and, and that's what I thought I was going to have the rest of my life,” he says. “But I had some success later in life with this reality show with my wife, and many other acting jobs. I went, let's go booyah. Let's go all the way and build not just you know, LEED silver or gold, but LEED Platinum, which is the highest MPG, if you will, for your home – the highest efficiency.”

As many Passive House Plus readers will be aware, LEED – short for Leadership in Energy and Environmental Design – is a voluntary rating system developed by the US Green Building Council to certify sustainable buildings and developments.

Projects are assessed under a range of indicators, covering carbon dioxide, energy, water, waste, transportation, materials, health, and indoor environmental quality, with credits available for a wide range of measures. To achieve a platinum rating, projects must score at least 80 out of 100. “What I like about the LEED points system [is that] they look at everything. Are you getting marble from Italy? You know, how far is that stone coming from? Are you making a lot of trash when you build the job site building this home? Everything that you do big and small is factored into the point system. You get to say your home is green or not green. And I liked that, that they look at everything over the lifecycle of it.” One thing it is missing is an embodied

ED BEGLEY JR

carbon score, as these calculations were very rare at the time, in particular for dwellings.

Given the progress now being made in this area Begley is open to the idea of appraising the building in these terms.

For Begley, the choice between conventional construction and a standard which strives to produce a healthy, low running cost, eco-friendly home should be a no-brainer – but it’s a no-brainer that many people still manage to miss.

“For so long we had it wrong here in the States, and I know, others got it wrong elsewhere. We would look at a building and ask: what's the cost of that building?

We'd look at labour and materials, and it's highly inaccurate to look at it that way.

What is the cost of running that building?

That's another big cost over its long life.

If you build it, right, as I have with my LEED Platinum home that I'm sitting in, right now, the cost of running it is very low.

It's just simply the future. It's not just the future, it's today, what we must do, because otherwise you just keep trying to heat and cool these energy inefficient buildings and we'll go broke trying to do it.”

The passive solar designed house comes with twelve-inch-thick walls to maximise insulation, with a steel frame superstructure.

“I know there's a tremendous amount of energy used to make steel, I get that,” says Begley. “But most steel is post-consumer recycled, ” he says. “What used to be a car is now a frying pan, what used to be a frying pan is now a car – you know that metal is just too valuable to waste. That's why you

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ED BEGLEY JR

INSIGHT

have those giant magnets, picking up cars in a junkyard and recycling that steel. It's less energy to mine it in the junkyard than it is to mine it in a mountain and make that ore into new steel.”

As one of America’s most high profile environmentalists for over half a century, Begley has been remarkably persistent in his efforts to win hearts and minds around to arguments that go against the national hegemony, and the largely unchallenged belief that bigger is better, that unmitigated growth is a good thing. Given how out of sync – how almost un-American – these ideas are, how has he managed to keep the fire lit, for want of a more climate-friendly analogy?

“I was much better at making the argument years ago when I was single, and now I'm not sure I win the argument in my own home all the time,” he says. “This home is a perfect example. It's a fine home – LEED Platinum, very low energy use, nine kilowatts of solar, a 10,000-gallon rainwater tank, grey water system, heavy efficiencies, and every matter you could, you could think of, but you know, it's bigger than I wanted. My wife wanted some bigger spaces, closet space, or what have you. And if you're going to be married, you’ve got to make concessions and can't just do it my way the way I used to. People want a certain amount of comfort, and I've become more sensitive to that.”

Begley points out that – though the new house comes in at almost 4,000 sq ft – over twice the size of his old house – the running costs are lower. “The electric bill is lower, the water bill is lower, the natural gas such as we use, it's pretty low. So, you know, you’ve got to balance and keep everybody happy.

I've always been comfortable in a very small place, because that's what I grew up in. My dad raised me in a 1,700 sq ft house, which is huge by world standard: 1,700 sq ft for just three people? Oh my god, what are we gonna do with all that space? But for most people in

80 | passivehouseplus.co.uk | issue 42

America, that's a very small house. But I was very comfortable with that the first 67 years of my life and thought that's the way I was going to be carried out in a gurney.”

Curiously, Begley reckons that moving to a larger house may actually help encourage reduced house sizes for at least one demographic: his well-heeled friends.

“We've got a lot of our high-profile friends to look at our place to go ‘Wow! I can live in a house as small as Ed’s.’ To them, my house is very small, at 4,000 sq ft. To them, that's like a shack. So, it's all in the eye of the beholder.”

At times the tendency for many environmentalists, horrified at the unfolding climate collapse, decimation of the natural world, and increasing disparity between the haves and have-nots, is to level righteous indignation at profligate public figures, and perhaps for a simple reason. Gallingly extravagant forms of recklessness like Kylie Jenner’s 17-minute private jet flights are a much easier target, than the rapacious corporate interests who have actively worked for decades to stymie regulation and create confusion.

Begley’s show business friends may not quite

meet such levels of disconnected decadence, but pontificating and pointing fingers isn’t his style. “I just refuse to judge my friends by their homes and their cars. I wouldn't have any friends. I encourage people. I do what I do. And you want to join me? Here's what I did. Give it a try. I try to be very inclusive. I think that's the best way to go. You get more people to join you if you're not always being divisive and trying to make people feel guilty.

I think a lot of people want to do something, you’ve just got to give them some choices that resonate with them.”

And Begley is not alone among his peers.

One of Begley’s friends, Bryan Cranston – who appeared alongside Begley in the final series of Better Call Saul, reprising his Breaking Bad role – built a 2,500 sq ft LEED Platinum beach house in the nearby coastal town of Ventura, designed to passive house principles. “Very modest home, beautiful place,” says Begley.

While Begley and Carson’s home is bigger, the activist in him has found other uses to justify the extra space. “One thing we do to mitigate that size, we're always having environmental board meetings here and different seminars and things,” he says.

“We're using it not just as a home, but a space to gather and meet and plan, you know, for environmental groups that I'm part of. So, the space is used wisely in other ways besides us living here.”

If ever there was a need for such activism, it’s now. Passive House Plus interviewed Begley just after the US Supreme Court had made a number of rulings which threaten to take America back to the dark ages, be it with regard to healthcare, women’s reproductive rights, or the ability of the Environmental Protection Agency to live up to its name, by limiting its power to compel states to cut emissions, a decision which Begley describes as “shocking. I don’t know where we're headed in America but were on the wrong trajectory. And hopefully, we can get it back to magnetic north here. But we've gone mad in so many ways here recently. I'm not sure what's next.”

INSIGHT

I just refuse to judge my friends by their homes and their cars.

But Begley is at heart an optimist, albeit an optimist staring into the void. A momentary lapse in the face of such inexplicable malevolence aside, he quickly comes up with an antidote to this despair: a plan of action. Rejecting the trope that all we can do is take personal responsibility in an act of futility akin to attempting to bail out the Titanic with a thimble, Begley puts forward an approach for meaningful progress based on three pillars. “One is personal responsibility. Doing all the stuff that I'm known for – electric cars, solar panels, all that.

Wonderful. The other two are equally important and they must be similar strength and size. That is corporate responsibility.

And good legislation [and] government.”

Begley thinks back to his youth in the choked air of LA. “If you don't have all three we wouldn't have cleaner air in LA, which we do have now from the first earth day in 1970,” he says. “Because people did personal responsibility stuff like me. There were good laws. The Clean Air Act signed by an environmental radical by the name of Richard Nixon – he signed the damn thing.

And then corporate responsibility, getting corporations to agree to these things and do things right. You have to have all three.

It's not all on us the way some people were

trying to frame it.”

There’s a famous quote from Alfred Hitchcock. “I deny that I have ever said actors are cattle. What I said was: ‘Actors should be treated like cattle.’” We can only speculate what Hitchcock would have made of an actor like Begley, who is anything but bovine in how he uses the platform that his fame has given him. For Begley’s part, while he tries to tread carefully, the compulsion to move between acting and activism is too great. “A certain responsibility goes with this when you are given the megaphone or the microphone to talk about weighty matters,” he says. “You don't want to cry ‘fire’ in a crowded theatre. But if I’m supposed to go out and do a song and dance and the fire marshal, taps me on the shoulder and says ‘there’s a fire smouldering in the basement, make sure we evacuate row by row,’ am I supposed to just go and do a song and dance after hearing that? Absolutely not.” Begley has no time for the naysayers. “The people [who say] ‘We don’t want to hear about your environmental bullshit, leave me alone.

You're an actor. Shut up and do your job.’

Not good enough. I've heard from the fire marshal. The fire marshal is the Union of Concerned Scientists, more than half the living Nobel laureates. All these great people with PhD after the name that have told us about climate change, and plastics in our ecosystem in the ocean, loss of coral reefs, amphibians dying off – all the stuff that we know about, we know about from the fire marshal. The people that know about such things that are scientists, so we have to promote that message and do it responsibly.”

ED BEGLEY JR

Long may he continue to get the message out there. It’s one thing for a public figure to speak out on an important issue. It’s another thing entirely when they do so with such inexhaustible persistence, with such intelligence and knowledge, and with such humility. On the first occasion Begley appeared on The Simpsons, playing himself, at a deforestation protest rally, Marge asks him if he’s going to join her in the protest bus. “I prefer a vehicle that doesn’t hurt Mother Earth,” he says. “It’s a go-cart powered by my own sense of self-satisfaction.” He puts on a helmet wired to the car, and whirs off over the horizon.

You could be forgiven for thinking a magazine whose standard fare is the technical minutiae of sustainable building in Ireland and the UK has no business interviewing American celebrities. But then Ed Begley Jr is not your average celebrity. His unfussiness, humility and willingness to really engage driven by a sense of purpose to help tackle crises of unprecedented scale and consequence, is inspiring. We live in a time of division, at an inflection point in our planet’s history. If we’re to have any chance of staving off disaster, it’ll be through following the examples of people like Ed Begley Junior. n An extended version of Jeff Colley’s interview with Ed Begley Jr has been turned into an episode of the Zero Ambitions Podcast, with co-host Dan Hyde, and is available on Apple Podcasts and Spotify.

ph+ | ed begley jr insight | 81

MARKETPLACE

PASSIVE HOUSE+

Marketplace News Airflow launches MVHR cooker hood A irflow Developments has launched a compact mechanical heat recovery (MVHR) unit with an integrated cooker hood, designed to combine ventilation and extraction of cooking odours.

The company’s Adroit DV51CH won domestic product of the year at last year’s Heating & Ventilation Review awards and was highly commended at the Heating & Ventilation News awards.

Both the heat recovery unit and the cooker hood are manufactured from metal and supplied with a grease filter, protecting the unit from cooking particles and oil build-up, and providing a fire-safe ventilation solution for kitchen installations.

Airflow Developments said that the Adroit DV51CH recovers up to 84 per cent of the heat from the extracted air via a “highly efficient conduction process”. The DV51CH comes with a built-in humidity and CO2 sensor. The on-demand ventilation control feature means that air flow levels are adjusted automatically depending on indoor CO2 levels.

Meanwhile, the Adroit ‘Cloud’ function allows users to control ventilation from their smartphone, tablet or PC. The front panel of the cooker hood also has four touch buttons to open and close the damper position, change the ventilation settings, adjust the brightness of the LED light, or turn it on and off.

Airflow offers one of the largest ranges of passive house certified MVHR units (with fourteen units in total), comprising the Adroit range, the Duplexvent Flexi range and the Entro–H range. All of the company’s passive house certified MVHR units offer one hundred per cent summer bypass to isolate the heat recovery function during the hotter months and prevent overheating.

They are also fitted with high-grade filters to provide a clean indoor environment, protecting the occupants from dust, pollen and any other airborne pollutants as well as protecting the unit itself from getting dirty.

Airflow Developments is a member of the Passivhaus Trust. For more information see www.airflow.com •

(top) 7 of the 14 MVHR units from Airflow’s Adroit range; (above) an illustration indicating how seamlessly the integrated cooker hood of the new Adroit DV51CH fits into kitchens.

Viessmann launch two new compact heat pumps

V

iessmann has launched two new monobloc air source heat pumps, the Vitocal 150-A and Vitocal 151-A, which the company said are ideal for replacing boilers in the UK’s existing housing stock.

Each is available with outputs of 10, 13 and 16 kW. Both the wall-mounted Vitocal 150-A and the floor-standing Vitocal 151-A have a high maximum flow temperature of 70C (at an outside temperature down to -10C), meaning that in most cases they can use existing radiators and do not require underfloor heating, Viessmann said. Both use the same control platform as Viessmann’s boilers, so that they are compatible with the rest of the company’s product range. And both integrate previously separate system elements in the indoor unit (IDU), reducing installation time by a full two hours, according to the company.

The Vitocal 151-A has an integral, 190litre hot water cylinder, yet is highly com-

82 | passivehouseplus.co.uk | issue 42

pact. Both models are also designed to be extremely quiet in operation. Viessmann said that the Vitocal 150-A and 151-A take up 60 per cent less space in the home compared to conventional heat pumps.

The buffer tank, expansion vessel, and overflow valve – components which usually have to be installed and connected separately – are now integrated in the IDU. To ensure a very low global warming potential (GWP), the system uses R290 (propane) refrigerant, with a GWP of less than one.

With a COP (coefficient of performance) of 4.9-5.0 (according to EN 14511 for A7/ W35 and depending on the model), the new heat pumps generate up to five times the usable heat for heating and hot water from one kilowatt hour of electricity and heat from outside air.

Viessmann’s marketing director, Darren McMahon, said: “When the time comes for homeowners to replace their boilers, more are now looking for renewable alternatives.

(above) Viessmann’s new air to water heat pump range includes the wallmounted Vitocal 150-A and floor mounted Vitocal 151-A and indoor unit.

The Vitocal 150-A and 151-A air source heat pumps help answer this growing need.

The end-user gets an efficient, environmentally-friendly solution that delivers heat like a boiler; the engineer gets a unit that’s much easier and faster to install. Having fewer pieces of equipment has cut the time needed for installation by 90 minutes.”

Installation training courses for these new products are available now through the Viessmann Academy. •

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Launching a new product is never easy, but in the space of only two months we’ve received over 150 enquiries through two issues of the magazine and all have been very fruitful. We have been quoting straight after the magazine is out. A lot of the customers enquiring have genuine current projects and this is reflected in how many respond to our follow ups.

It is no doubt in my mind that this team are one of the best I have dealt with out of the many publications we use. They deliver and they deliver quality!

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To enquire about advertising, contact Jeff Colley on +353 (0)1 2107513, or email jeff@passivehouseplus.ie

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Ecological launches Passive EcoWall to tackle embodied carbon ‘blind spot’

E

cological Building Systems welcomes the fact that embodied carbon has at last come into focus in the UK. The Committee on Climate Changes’ sixth carbon budget report set out a detailed and achievable ‘balanced’ route for the UK to drastically reduce emissions by 2050. This includes reducing emissions from the built environment, both embodied and operational, which contribute up to 40 per cent of the UK’s total carbon emissions. The report recommends rapidly increasing the use of wood in construction to serve as a form of carbon capture and storage, as well as to displace carbon-intensive materials such as concrete.

In recognition of this challenge, Ecological Building Systems has developed Passive EcoWall, a building concept that uses carefully selected materials with significantly lower carbon emissions to offer extremely high levels of thermal efficiency, up to and beyond that required for compliance with building regulations, attaining passive house levels of performance.

Ecological’s Passive EcoWall provides a complete low energy, diffusion open building concept based on tried and tested passive house principles. It utilises Gutex woodfibre natural insulation, Finsa SuperPan VapourStop airtight and vapour control racking

boards, and the Pro Clima airtightness and wind-tightness system. NZEB, certified passive houses and modular buildings have already been constructed in the UK using this principle, delivering significant reductions in energy use and high levels of comfort. The specification can also include Thermo Hemp Combi Jute, a combination of hemp and upcycled jute fibres.

“Our Passive EcoWall concept provides a truly breathable structure. It incorporates an innovative internal structural board, SuperPan VapourStop, which is pre-fitted with a vapour control and airtight layer. This in turn increases efficiency on site, reduces installation costs and provides a continuous internal airtight seal for buildings that reduces the risk of interstitial condensation,” said Niall Crosson, group technical manager with Ecological Building Systems.

“As modern structural elements are sealed more than ever to attain higher levels of airtightness, moisture management is essential, particularly in our damp climate. Unlike many conventional wall systems, our Passive EcoWall also incorporates an external insulation layer of Gutex woodfibre boards,” said Crosson. “These provide high levels of thermal and acoustic insulation and are also extremely vapour diffusion open, allowing

structural elements to dry out rapidly. In this way, condensation risk is dramatically reduced.

“Passive EcoWall is a perfect example of how it is possible to combine low energy construction with more sustainable building materials that have significantly lower carbon emissions. Utilising building methods such as this will be key to not only reducing operational emissions, but the embodied emissions blind spot of the building industry in the UK.” •

(above) Internal and external views of the new Passive EcoWall concept from Ecological Building Systems.

Tramex launches remote environmental monitoring system

W

orld-renowned Irish moisture meter pioneer Tramex has launched a new cloud-based system for budding building pathologists – to enable users to remotely monitor buildings and detect potential indoor air quality, temperature and interstitial condensation issues.

The Tramex Remote Environmental Monitoring System (TREMS) is a new cloud-based system designed, developed and built in Ireland by Tramex, for the most accurate and reliable monitoring and recording of a projects’ environmental temperature and humidity conditions.

With no monthly subscription fees, SIM included for 4G coverage, up to 15 years battery life, exceptional accuracy, and an easy-to-use and secure cloud-based platform, the Tramex Cloud provides simple reporting, parameter adjustment, alert no-

84 | passivehouseplus.co.uk | issue 42

tifications and downloadable data.

The system enables users to monitor sensors from multiple buildings, floors or projects, or multiple rooms within a single building without having to set foot on site once the system is set up.

“All of your projects’ environmental data can be monitored remotely, any time, any place, from anywhere,” said Tramex’s head of monitoring Ryan Stanley. “TREMS is your reliable partner for precise and accurate remote temperature and humidity monitoring.”

Stanley sheds light on how the system works: “Tramex Cloud sensors are placed in the required areas and send temperature and humidity readings to the user’s Tramex Cloud station. The secure network then connects to the Wi-Fi supplied by the Tramex station and sends all data to the Tramex Cloud platform. In your Tramex Cloud account all collected data can be viewed as files and in visual charts or graphs and compiled into reports. Why drive to a single site to take readings, when you can surf to the Tramex Cloud and monitor many projects all in one place with no subscription fee.”

A secure logging-in process into the

Tramex Cloud allows required personnel access to the temperature and relative humidity data.

All temperature and humidity readings are stored on the Cloud platform and can be downloaded as CSV, Excel files or jpegs.

Reports are generated for a quick glance view with colour-coordinated lines for even easier viewing.

If the parameters on site are of a critical nature, TREMS can issue alert notifications if the sensor readings reach the set parameters.

Alert notifications can be sent to site agents for a quick resolution, or to an office for reference. Project information can be made accessible to all that require it.

A family-owned Irish company founded in 1974, Tramex developed the world’s first non-destructive moisture meter, and their solutions – which also include interstitial probes – are used by experts and building professionals around the world to understand how buildings behave in terms of moisture and temperature.

For more information visit: https:// tramexmeters.com/remote-environmental-monitoring •

PASSIVE HOUSE+

Partel appoint Dara McGowan as director of UK region

L

ow energy building product developer Partel has appointed Dara McGowan as a director of its UK region. McGowan takes up his new position with a reliable knowledge of the Partel business, which he joined in 2021 as a technical consultant. He was previously responsible for air and weather sealing, ventilation design, and technical training in Ireland and the UK, along with technical business development.

“In planning to grow Partel’s capacity, expand the current UK reach and our technical consultancy capabilities around the building components we develop, we are pleased to welcome Dara McGowan as our first director in the UK,” said Partel founder and director Hugh Whiriskey.

McGowan added: “I am delighted with this new position, and honoured to be given the opportunity. I am excited about growing Partel UK over the coming years and look forward to contributing to our strategy, business development and company values. We are recognised as a market leader in Ireland, and I believe that we should reach this potential in the UK as well. Our building components, services and technical team are amongst the best in the industry, and I am looking forward to showcasing that in the UK.” McGowan completed a Master of Architectural Science in sustainable building design and performance, in University College Dublin, prior to starting his career in the construction industry.

He is a certified passive house designer, certified passive house tradesperson and building energy rating assessor (the Irish version of a SAP assessor).

He has worked with Ireland’s Department of Housing to develop and deliver training courses for contractors and designers, helping them to understand the new Part F and Part L introduced in Ireland in 2019. He has also written questions for Passive House Institute examinations and has lectured at the University College Dublin, Technical University Shannon, and the Munster Technological University.

Hugh Whiriskey added: “I am confident Dara is prepared for this position and will ensure a meaningful transformation of the technical solutions and practices Partel UK provides. We are looking forward to reinforcing the pursuit and deployment of a sustainable growth strategy, based on collaboration.”

For further information about Partel, please visit www.partel.co.uk. •

MARKETPLACE

Kore launches low carbon EPS

L

eading EPS insulation manufacturer Kore is set to launch Kore Low Carbon EPS onto the Irish market – unlocking dramatic reductions in embodied carbon without affecting performance.

Manufactured using BASF’s Neopor BMB (Biomass Balance) or Styropor BMB – the new insulation achieves substantial embodied carbon reductions by using renewable resources such as bio-naphtha or biomethane derived from organic waste, crops or vegetable oils as feedstock in the very first steps of chemical production.

Based on data from Environmental Product Declarations (EPDs) obtained by BASF, Neopor BMB reduces embodied CO2 emissions by at least 80 per cent compared to Neopor during the manufacture of the raw material. Insulation boards made of Neopor BMB have the same properties as their fossil equivalents. In addition to operational carbon savings delivered over the product’s lifespan, Kore’s early stage analysis indicates that embodied carbon savings of at least 60 per cent may be achieved by the boards during production – figures which are subject to verification.

Launching initially with Kore Floor, Kore Fill Diamond, Kore Roof Insulation, the Kore Insulated Foundation System, Kore External, Kore Void Formers and Kore Geofoam, this exclusive offering is available in a variety of EPS grades this autumn.

Kore was Ireland’s first expanded polystyrene manufacturer to hold an EPD for EPS, and is in the process of obtaining an updated EPD to integrate the Kore Low Carbon EPS product line.

Commonly used in low energy buildings across Ireland and the UK, Kore’s EPD-verified products offer additional credits in building sustainability assessment schemes like the Home Performance Index, LEED (Leadership in Energy and Environmental Design) and BREEAM (Building Research Establishment Environmental Assessment Method).

Kore estimates, based on information provided by BASF, that the company’s low carbon product range will save 2.223 kg CO2 equivalent for the production of 1 kg of EPS versus standard Kore EPS. A typical home of two floors, 100 m2 will save 800 kg CO2 by choosing Kore’s low carbon solutions.

According to Kore’s operations director, Pauric Kavanagh: “With Kore Low Carbon EPS, our customers will receive identical quality and performance of the product that they are used to, while making an effort to reduce climate change through utilising a more sustainable material.” •

(above) Kore’s new low carbon EPS being cut on the production line.

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D R TO B Y C A M B R AY

COLUMN

Is it okay to retrofit heat pumps before building fabric?

How flexible can heat pumps be to handle what may be inexactly defined heating demands, asks Toby Cambray?

A

couple of issues back I discussed the idea that in order to decarbonise our housing stock as rapidly as possible, the dogma of fabric first should be questioned. This led to an interesting question from Lloyd Alter, of Treehugger.com: “If you install a heat pump first and do the fabric second, is the HP not then grossly oversized? I understood that’s a problem with them.”

While this is a valid question, it’s an area where the solutions have evolved with technology and the answer is different to what it would have been if it was five or ten years back. I’m primarily talking about air source heat pumps in this article, but some of the points apply to other types.

The problem that Lloyd alludes to is to do with the risk of “short cycling.” This comes down to a straightforward way you can control a heating system which I like to call “IT Crowd” control; switching it off and on again. This is how conventional fossil boilers and thermostats work – they run, warm the building up, then switch off (fossil boilers can modulate but let’s keep it simple for now).

The controller has a little hysteresis, which means it doesn’t immediately switch back on as the temperature drops, but permits maybe a degree of drop and therefore some period of time before the boiler kicks back in. Due to the mechanics of heat pumps, this leads to inefficiencies – it takes a bit of time and energy to build pressure and temperatures back up to operating conditions, which you don’t get back at the end of the cycle. It can also shorten the life of the compressor as a lot of the mechanical stresses occur on start up.

But as with many things in sustainable energy, its more complicated than that. For a start, how do we size heating systems anyway?

We *should* do a full set of heat loss calculations, and produce an “accurate” peak heat load – let’s say 10 kW for a typical-ish, not very well insulated house. If we’re a bit mean we might pick design conditions of 0C outside and 20C inside, giving 500 W/K. Assuming our heat loss factor is correct (spoiler alert, it’s probably not) if we went for a more conservative 24C inside and -6C outside, we’d need a 15 kW heat pump – the size is very sensitive

86 | passivehouseplus.co.uk | issue 42

to the conditions we pick as our worst case.

On top of that, it’s not uncommon to add an arbitrary 10 or even 20 per cent to a heat loss even for heat pumps, sometimes disguised as a “warm up factor” but is basically a fudge or comfort margin.

Readers of Passive House Plus will have some inkling of how inaccurate heat loss calcs might be (assuming they are done at all). I doubt that many (if any) installers on typical heat pump installations insist on an airtightness test being done, or carefully document and account for all thermal bridges (I was delighted to hear Nathan at the BetaTeach podcast mention he’s used a co-heating type test to quantify this, but it currently seems unlikely this will be a mainstream service). How are the U-values arrived at? If we aggregate all these inaccuracies, do we tend to over or underestimate? But more importantly, how much does it matter? After all, looking at the range from one popular manufacturer, the domestic ASHPs come in 6, 8.5 and 11.2 kW. If your heat loss calcs come out at 7.25 kW, you have to choose to be 20 per cent oversize or 14 per cent under.

There are several more elephants in this room of uncertain heat loss. Firstly, there is the vast majority of the year when it’s nowhere near our worst-case scenario of zero or even -5C. A heat pump therefore spends most of its working life “oversized” compared to the actual demand, and we don’t worry about that.

Another lurking proboscidean is hot water; in order to re-heat a cylinder in a sensible period of time, we need a certain amount of power. A one hour re-heat of 200 L would require about 10 kW – significantly more than the peak heat loss from a well-insulated flat for example. There are alternatives to heat pump powered cylinders, but they are generally compromises and the subject for another column.

It turns out that unlike the Irish border we can throw a bit of technology at this issue to make it go away, namely inverter driven compressors. Happily, with a few exceptions, many new heat pumps have this feature. The inverter is a like a dimmer switch to the lightbulb’s toggle switch, allowing efficient operation at part load. This means that the heat pump’s thermal output can be turned down

without (or at least, with less of) an efficiency penalty. There’s a lot more to unpack there, and I’ve probably upset a lot of heat pump engineers by oversimplifying. There are a couple of important caveats here – firstly that the hydronic design (i.e., pipe and radiator layout and sizing) is on-point, and secondly that the system is (re)commissioned to a high standard. Both of these are large rabbit warrens in their own right; many subtle parameters can (and should) be optimised on some modern units. This means that we perhaps shouldn’t be too worried about the fabric retrofit (if it does indeed happen, and to the standard assumed) undermining the performance of the heat pump. It would also not be beyond the bounds of possibility to swap it out for a smaller unit, passing the partially used one on to a larger home.

An alternative approach is to put in an undersized heat pump before a fabric retrofit. This means that on the coldest days, the house might be a little chilly, or it is necessary to top-up with some direct electric heaters.

While this has a running cost and carbon implication (although average grid emissions are now very low, the periods of highest demand depend on higher emitting generation), and have an implication on the infrastructure, this would of course be mitigated on completion of the fabric retrofit.

So, should we worry about accidentally oversizing heat pumps in a step-by step retrofit? Perhaps less than we used to. All of this depends on some important assumptions of course: that the heating system is carefully designed, with prior knowledge of the fabric retrofit; that a good quality unit is used with an inverter drive and a comprehensive controller; that the heat pump system is commissioned to a high standard, and re-commissioned after a deep energy retrofit to suit the new load; and that ultimately, that fabric retrofit is completed to a good standard. n

Toby Cambray is a founding director at GreenGauge and leads the building physics team. He is an engineer intrigued by how buildings work or fail, and uses a variety of methods to understand these processes.

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