Cambridge Architecture Gazette CA56

CAMBRIDGE ARCHITECTURE

Spring/Summer 2008

56 architecture urbanism environmental issues • in the Cambridge city region

Sustainable Living XL L M S

Riverside housing reviewed Trinity Hall student accommodation Two new-build private houses Four extension and refurbishment projects

plus News and views Letters and interview City housing research project

THE EDITORS

IN THE NEWS

THE BIG ISSUE

TRIUMPH BY DESIGN The new Riverside Bridge ticks all the right boxes.

Both siting and design were the outcome of widespread public consultation, the design selection was confirmed by competition and the construction was undertaken through a framework agreement. Not only all that but the Cambridge Evening News, instead of acting as the voice of the protestors, was deeply involved in the participation and selection process.

Anyway, there were no protestors.

Sustainability has never been higher on the construction industry agenda.

Given that the sector is responsible for around half of the world’s resource usage and up to 40% of all energy consumption, this is not before time.

Design and building currently enjoy wider media coverage than ever before, thanks to a wealth of lifestyle magazines, supplements and television programmes – and these media outlets are inspiring a larger population to get involved.

This issue of the Cambridge Architecture gazette – edited by a group of young Cambridge architects – looks at a range of responses to the challenges that lay ahead. Prefabrication and off-site construction are growing in popularity, the dream of zero-carbon development is becoming a reality, and people are now more au-fait with the implications of material selection and the issue of embodied energy: the energy involved in collecting, processing, distributing and maintaining building materials.

Onsite energy creation is also fast becoming the norm, be it solar thermal, photovoltaic panels, microgeneration wind turbines or groundsource heating and cooling.

Sustainability also encompasses lifestyle choices: Cambridge offers a dense living environment in close proximity to workplaces, services and amenities, exemplified by the widespread use of the bicycle as vehicle of choice of the city’s inhabitants. Contrasted with this is the draw of the suburb and countryside, and with it the promise of space and nature, only marred by the reality of driving around Cambridge and its surroundings.

The selected projects explore the range of scales of development characteristic of Cambridge living.

The extra-large section (XL) focuses on infrastructure and urban design, followed by a review of a recent large (L) student housing scheme for Trinity Hall. We then look at two new-build private houses (M) and four smaller refurbishment, conversion and extension projects (S). Returning to the scale of the city is an outline on current research on retrofitting Cambridge’s existing housing stock to address climate change. We end with an interview with engineer Philip Cooper on the wholly sustainable virtue of permanence in construction.

COLEN LUMLEY Each of the 43 issues of the Cambridge Architecture gazette published over the past 18 years was co-edited by Colen Lumley. His retirement from the Editorial Group last autumn brought to an end a very distinctive contribution. His concern – and that of his alter-ego, Herman Ewticks – for the architecture, planning and landscape of the city and the county was always uppermost.

That the gazette now enters its twentyfirst year of publication owes much to Colen’s generous contribution of both time and effort.

Cambridge’s many bridges include the elegant timber mathematical bridge, the enclosed Bridge of Sighs and the slender, privately commissioned mid-Twentieth Century Garret Hostel bridge. Phil Crack, the County’s Head of Infrastructure and Delivery told CAg that ‘We were fully aware of this heritage and wanted to ensure that Cambridge’s first new bridge for 40 years was something that we would be proud of.

There was tremendous support from the then Director of Transport, Brian Smith, and the Council.’

The City was equally supportive. As Nichola Harrison, then Executive Coucillor for Environment and Planning and now a County Councillor, recalls, ‘The Brooklands Avenue saga had raised the ante on design and we’d just had a successful competition for the new City toilets.’

But, as the City’s former Director of Planning, Peter Studdert, emphasises, ‘Much of the credit must go to the County.’

The public consultation considered three possible sites of which the most popular was selected.

The design competition was organised by Richard Donoyou of the Peterborough Environment Trust – selected because of his experience in running a similar competition for the Peterborough Millennium Cycle Bridge. Six engineering firms were invited to compete. The resulting entries were published in the CEN and a poll held on the preferred one.

Next, a group of assessors, both lay and professional, and the assessors – unaware of the public’s preference – picked the same ‘winner’, the Whitby Bird entry.

Echoes of Calatrava Designed in collaboration with the sculptor Gerry Judah, the new bridge has that striking white skeletal form which has been a common bridge motif ever since Santiago Calatrava’s Alamillo bridge in Seville of 1992. Whilst this means that it is not unique it does firmly place the bridge into a successful and memorable genre – much like the cast iron Victorian bridges of the nineteenth century or the compressed stone arch structures elsewhere on the Cam. The most immediately striking aspect of bridge is the asymmetric suspension arch which supports a smooth bifurcating deck slung carefully between the two banks.

However it is what is not at first obvious that really makes this bridge interesting. It is the manner that the

designers have negotiated the large level difference while maintaining a shallow and accessible slope throughout that is most successful and makes this bridge far longer than the river span would initially suggest. The ramped design is kept shallow as the access on Riverside has been skilfully designed to run parallel to the road thus avoiding the usual steep dogleg which is the standard solution utilised by the other Cambridge pedestrian bridges. The deck then splits in two over the water, making a grand gesture of the separation between cyclist and pedestrians which is somewhat fitting for Cambridge. At this point the view of the river is maximised, a point that will certainly not be missed by the rowing coaches. Finally, the two parts rejoin and begin a long curving descent across the flood plane of Chesterton Meadows with occasional resting decks suitable for bird watchers or those merely wishing to reflect on the new structure.

The bridge is yet to be handed over by contractors Balfour Beatty but, so far, everyone seems pleased at the outcome.

So why can’t the County always use the competition route to select designs for bridges at significant points – such as the bridge carrying the new AddenbrookesTrumpington access road over the railway? Many see this bridge as one of the new ‘gateways’ to the City.

Crack says it all depends on everyone agreeing on the significance of the bridge. ‘We would only hold a competition for a landmark bridge – it’s an expensive process and outcome’.

STRAIGHT FROM THE CATALOGUE Cambridgeshire already has the longest guided bus track in the UK – 3.6 km so far. Talking about it recently to the Cambridge Forum for the Construction Industry, the County’s Head of Delivery, civil engineer Bob Menzies, managed the remarkable feat of omitting any mention of the bus/passenger interface: the humble bus stop. Architects hoping for a bespoke designed system are going to be disappointed.

Planning – or, rather, lobbying – for the Cambridgeshire Guided Busway commenced over seven years ago. Starting with the Cambridge and Huntingdon multi-modal study, it progressed through numerous stages including a public inquiry and a mysterious ministerial five month delay before funding was finally approved. Even then the brakes appeared to have stuck on the wheels of Whitehall. Work started in September last year and is due for completion next Spring.

The guide rails are cast by contractors Edmund Nuttall Ltd. in a huge shed on what will shortly be the site of the first part of Northstowe. From there, they are assembled on adjacent site that will eventually become a park and ride. It is an impressively ‘light on the ground’ operation – right through to the grass growing between the rails. Laying tolerances are an impressive + or – 5 mm horizontally and 6 mm vertically. On soft ground, screw piles have had to be used.

Bridgeworks so far look pretty unsophisticated – whether a matter of modifying an existing bridge (as at Long Road) or replacing one over the Ouse (near St Ives). Which is not to say they are inappropriate. They do the job and are often almost invisible. Where the skill really comes in is ensuring that any existing traffic is diverted for as short a period as possible.

So what about the bus-shelters and stops? Menzies says that these are likely to come from ‘high-end catalogues’ – the kind of quite elegant and sophisticated street furniture that we associate with the Netherlands and some North American cities, complete with information screen, help point, ticket machine and CCTV. Park and Ride landscaping will be similar to that already completed elsewhere by the County around the city.

Recent trials suggest that the CGB will offer a smooth ride. It’s already attracting interest from other cities such as Bristol and Luton. And there’s a certain engineering pragmatism about it that one has to admire – from the freshthinking about how to set up a truly demanding multioperator service to the use of that ‘high-end’ street furniture.

Adam Peavoy/Peter Carolin

XL John Sergeant

LIVING BY THE CAM The colleges did it first. They turned their own river frontage from commercial highway into a garden ornament. King's make-belief canal was probably inspired by Audley End, with an even smaller river and narrower basin. Upstream, King's (Foster's) Mill, the source for flour for the town, closed in 1898, the gas works in 1971 and the central sub-station stood empty from the 1950s until Beaufort Place was built in 1985.

Now there are no 'deleterious' infrastructures to prevent developers doing the same. As all the world knows, water frontage sells houses.

did the same, combining a grand terrace from which the Thames could be surveyed with warehousing below. St. John's College does this best in Cambridge. But once a road severs buildings from the river's edge that vital, Venetian, property of a wall plunging directly into the water is lost. The problem then becomes prosaic: how to enjoy a private view out while avoiding passers-by enjoying their's in. The larger projects 'solve' it by throwing a cordon sanitaire in front; water in 'Eights' (1); parking or/ and gardens in Riverside Place (4) and 'Bart's'. The C19 terrace houses solve it simply by using the rise in ground level (where it exists) to raise their ground floors above eye-level (2). Water View (6) and Stourbridge both fail; upper floor flats gain privacy and view by sacrificing the ground floor, where privacy is achieved only by desperate planting, heavy blinds or abandoning the use of decks and french doors.

Cordon-sanitaire by water (1)

Raised ground level privacy (2)

Fen Ditton’s identity needs defending

A riverside site ripe for the picking

A walk downriver from Midsummer toward Stourbridge Common takes in the north west-facing bank from Elizabeth Way Bridge (1971) to the Railway Bridge, a landmark for rowers. Along the way it is possible to inspect Eights Marina, 1990's, in 'Maltings Vernacular' (1); a terrace of decent late C19 terrace houses which make no special recognition of their position curving along a bend in the river: they have small gardens and bay windows as elsewhere (2); 'Mallards' (1970's) with its 3 storey bay (3); Riverside Place (2006) in 'London Docklands City-bonus modern' (4); St Bartholomew's Court (Barts) in stonetrimmed 'Edwardian-bethan' (2005) (5); Water View (a recent 4-storey fully-glazed block) (6); Riverside House, a 1980's brick formula of flats with maisonettes above (7); and Stourbridge House (late 1960s) (8) – in that sequential order. On the opposite bank next to Chesterton Church are a number of 6-storey south-facing blocks - 'Vie la Riviere' (sic) (9) some 50m from the water, currently under construction by Redeham Homes, and due to be linked to Riverside by the new pedestrian and bicycle bridge (10).

There are always fundamental principles involved in residing near a river. If you are rich and powerful enough you build from water to road (which you define). The Houses of Parliament, like Whitehall Palace before it, still manages the feat. Somerset House lost its magnificent river facade when the Embankment was built, and the Water Gate lost its function. The Adam brothers' Adelphi

Location plan

Bloomsbury and Bath, Regent's Park also, succeeded by loading '2nd and 3rd class' houses onto the cachet, the selling point, of the '1st class' frontage. Thus St. Bartholomew's Court composes its lumbering facade about a grotesquely over-scaled central archway (large enough for emergency vehicles) (5) leading to a very ordinary 2storey interior that cannot decide whether it is a courtyard or triple array of terraces. Riverside Place does much the same vertically, where frankly contemporary glazed penthouses respond to their special position(4). This is the best addition to what is generally a rather sorry story. Its urban scale is needed to deal with a narrow site limited by a steep bank supporting the blank block of Tesco's behind.

On the other side of Newmarket Road lies the new retailshed zone of the city, B & Q, Homebase, Habitat... All this developer-led rebuilding, housing and retail, lacks a coherent road structure; what exists is permanently congested and likely to become more so.

Post-Thatcherian gentrification of London's Docklands was achieved through social exclusion, CCTV cameras and razor-wire to keep out the deprived surrounding communities, and it will be interesting to see how Cambridge manages this facet of riverside development.

Like the Thames, the Cam takes its effluent downriver, and it is there that processing industry of brickworks, gas, sewerage, grew up. Today Fen Road still has car dumps and caravan sites. Now there is talk of a flood-relief waterway paralleling the river, of re-siting the sewage works in order to build more housing, and a riverside park with Rowing Lake beyond Milton. It is to be hoped that the precious identity of the river villages can be saved from absorption: Fen Ditton, no less than Grantchester, needs defending.

Key: 1 Eights; 2 C19 terrace; 3 Mallards; 4 Riverside Place; 5 St Batholemew’s Court; 6 Water View; 7 Riverside House; 8 Stourbridge House; 9 Vie la Riviere; 10 new foot and cycle bridge

Gardens and penthouses (4)

Lumbering façade and …

… court or terraces? (5)

Exposed ground floor (6)

L Bobby Open

A GARDEN FOR LIVING IN Trinity Hall Wychfield Student Accommodation Storey’s Way Cambridge

Room-in-the-roof

Typical room

2

1

G Floor plans

Sectional perspective

RH Partnership’s new Wychfield site student accommodation development takes its place on Storey’s Way alongside recent buildings by Allies and Morrison, van Heyningen and Haward and Cottrell and Vermeulen.

In its scale, massing, materiality and orientation, the scheme aims to mediate between the various conditions of the surrounding context: the Wychfield site, the open fields to the west, the hard edge of Lasdun and MacCormac Jamieson Prichard’s Fitzwilliam College to the east, and the large detached houses of Storey’s Way to the south.

Never having previously worked for Trinity Hall, RH Partnership won the commission in 2003 in an invited competition involving Edward Cullinan Architects, MacCormac Jamieson Pritchard, and Freeland Rees Roberts. Their entry proposed two possible options for development: either splitting the accommodation into separate pavilion buildings, or into linear elements. On winning the competition, 6 months of design development with the College resulted in the latter being chosen as the favoured solution.

Within the context of the lush setting of the Wychfield site, the approach to landscape design was a key factor from day one, and must be considered along with the buildings themselves; significantly, the ‘percent for art’ requirement in this case was successfully argued as being best spent on the landscaping.

The Wychfield site itself is essentially split into two areas. The northern half along Huntingdon Road is an arrangement of pavilion buildings on an Arup Associatesmasterplanned north-south / east-west grid set around an informal courtyard; this includes buildings by Arup and MacCormac Jamieson Pritchard as well as the original arts and crafts Wychfield House of c. 1880. Hidden away between these buildings and the new site to the south is a mature garden containing a further Arup pavilion, with the College sports pavilion on the western edge.

The new scheme defines four external spaces: the driveway, Round Court, Greenhouse Court, and Green Lane. These negotiate the transition from Storey’s Way and the sports fields across the site into the Wychfield garden. It will be some time before the planting becomes established, but with the College gardeners occupying new accommodation on the northern edge of Greenhouse Court, this has every chance of being successful.

Already, it is clear that this court is a sensitively scaled space, something of a three-sided College court with the low greenhouse and tall trees forming the fourth edge.

Indeed, it was a critical decision to allow the houses of Storey’s Way views through the scheme to the tree belt.

Defining the external spaces are the three main linear blocks of living accommodation, the large gable ends of which are set back from Storey’s Way behind existing trees. These blocks are countered in plan by an ancillary building housing a meeting room, archive, stores and two further flats. The scheme can accommodate 156 individual dwelling units, currently divided into 136 bedsit student rooms and 11 flats.

In effect, what appear as traditional terraced buildings

Round Court

Green Lane

Forecourt

Threshold detail

actually break down into groups of approximately 21 bedsits centred around two staircases, 4 kitchenettes and a larger ground floor kitchen and living room: ‘houses’ forming small communities within the larger whole (the larger community being mirrored by the one at the Huntingdon Road end of the site). The size of these ‘houses’ is most apparent on the edge facing the driveway, where the terrace is split into three buildings, the western elevation of which is intended to reduce the visual bulk of the buildings with horizontal bands of oak cladding, and a slightly lower eaves height than the other two blocks.

Bedroom types – around 16m2 plus ensuites – vary from floor to floor, some with bays, some without, and those on the upper storeys with vaulted ceilings and dormers. Perpendicular to the main accommodation blocks are four transverse axes of circulation, associated with: the street-side cycle parking; the new porter’s lodge entrance; the car park, and finally with the gardener’s areas. The central two paths pass externally through openings in the two blocks that define the Green Lane.

As with the landscape strategy, environmentally sustainable elements are incorporated into the fabric of the scheme, rather than treated as add-ons: economy of plan-to-elevation areas, airtightness and high levels of insulation are twinned with a background ventilation system with heat-recovery plant in the roof space, making use of the chimneys as air intakes and outlets, as well as ventilation for the drainage system.

In terms of ideas, materials and forms, the architecture references Wychfield House’s arts and crafts lineage, including the Old English use of tile-hung and timber-clad upper storeys over a brick base, the steeply pitched roofs, and notions of truth to materials and respect for locality. Such references, however, are tempered by crisp detailing and contemporary materials.

Thus, on the one hand, one can sense Pugin’s theory of a picturesque approach to design, and yet this might be articulated by pre-cast concrete stairs and stainless steel handrails; similarly, in the variety of scales, materials and elevational rhythms, Ruskin’s idea of changefulness is apparent, but this is offset by Modernist elements like silicone-jointed corner windows. Who knows what Ruskin and Pugin would have made of the idea of a design-and-build contract, but it is at least evident that the architect’s intentions in this case have been carried through in the detail execution.

The external form conceals a steel framed roof structure above a masonry base with concrete floors. (A

Site plan (North at top left. Storey’s Way at bottom)

Greenhouse Court

further arts and crafts analogy might be made here: that of Philip Webb’s Standen in Sussex, a high-point of arts and crafts design that also conceals a steel framed structure, truth to materials not always being quite what it seems).

The designers in fact conceived of the construction in terms of prefabricated units, but this was factored out at construction stage. Paradoxically, RH Partnership’s building at New Hall, further down Storey’s Way, was designed for traditional construction, but the contractor elected to use prefabrication.

Next to the internalised campuses of Fitzwilliam and New Hall, the Wychfield site is something else entirely: a perforate landscape articulated by buildings intended to enhance their natural setting. In the Green Lane, one can sense something of the character of Storey’s Way when, before the car became king, it too was a green lane. And, even if the permeability suggested by the site plan now means the ubiquitous CCTV-lined metal railings, there remains the noble intention of giving something back to the public realm and using buildings to knit together our external environment.

Location plan (Storey’s Way at bottom) Client: Trinity Hall College, Cambridge Architect: RH Partnership (www.rhpartnership.co.uk) Services Engineer: Max Fordham LLP Structural Engneer: Whitby Bird Quantity Surveyor: Davis Langdon Landscape Architect: Cambridge Landscape Architects Contractor: AMEC Detail Architect: LSI, Norwich

M Zoe Skelding

Section north-south

NEXT DOOR DOWNSIZE House Sedley Taylor Road Cambridge

Architect: Nicholas Ray Associates (www.nray-arch.co.uk) Structural Engineer: Whitby Bird Services Engineer: Tag2 Quantity Surveyor: Sheriff Tiplady Associates Extensive sedum roof: Erisco Bauder (www.bauder.co.uk) Solar thermal panels: Viesmann (www.viessmann.co.uk) Glulam timber frame: Lamisell (www.lamisellbeams.com)

Isometric

Ground floor plan

Section east-west

Nicholas Ray Associates has designed this house for a couple approaching retirement; the plot having been formed on south side of the long garden of their existing home. It seems likely that a further dwelling was envisaged on the site in the 1930’s when the original house was constructed as there is a gap in the sequential street numbers. The Planners initially recommended the scheme for refusal due to the materials and form being unprecedented in the road. Planning consent was eventually granted at a meeting of the South Area Committee of the City Council and works are due to start on site in summer 2008.

The orientation of the plot is east–west and the long thin building is designed around a south-facing courtyard.

This is accessed from the single storey living space which also opens out onto the east-facing garden. The upper level partially overhangs the court – thus shading the glazing on the lower level. The double height stairwell on to the north of the house is designed to display the client's own paintings and is lit from the south at high level.

The ground floor is of masonry construction, with the

intermediate floor constructed as an in-situ concrete slab, the soffit of which is left exposed in the living room to take advantage of the thermal mass. The upper floor is constructed using a glu-laminated timber frame, a cost effective and environmentally sound alternative to steel and concrete frames. The frame is partially clad in cedar boarding and has an asymmetric copper roof which wraps over the east and west gables.

The concrete slab also forms the base for a sedum roof covering the single storey element of the dwelling over the living and dining areas. Sedum whilst providing a wildlife habitat, improves the thermal performance of the building and reduces pressure on drainage systems by allowing water to drain at a slower rate than traditional roof coverings.

The architect investigated the possibility of using a ground source heat pump but the ground conditions were found to be unsuitable. The underfloor heating will now be provided by a condensing gas boiler. The domestic hot water requirement will be largely met using solar thermal panels installed on the southern slope of the roof.

RADICAL REBUILD Section

This three-storey house is currently under construction and due for completion in October 2008. The site was formerly occupied by a two-storey house constructed in the 1930’s with single-glazed Crittall windows, solid walls and an uninsulated roof space. A study conducted by the architects indicated that, even with thermal improvements, the existing house would have consumed eight times more energy than the house now under construction. It took a year to gain consent for demolition and obtain planning permission for the new house. The design responds to the north-south orientation of the plot. The north or street elevation has a steeply gabled structure encased in cedar shingle which forms a retreat to be used as a music room, beyond and above which is a patterned glazed rain-screen set against a back-drop of render. A classical rhythm is established on the south or garden elevation with larger areas of glazing set behind the free-standing structural frame. The bedrooms and living space are protected from overheating by permanent timber louvers on the upper floors and by a sailcloth awning suspended from the structural frame on the ground floor.

Photomontage of house in context

House under construction

The dwelling is constructed with a glulam timber frame and cross-laminated structural timber panels. The panels are pre-cut in factory conditions to form door, stair and window openings – thus enabling the external envelope to be erected in a shorter time than with traditional construction. The lack of thermal mass in the lightweight external skin is compensated by the heavier construction of the rendered blockwork shaft rising vertically through the house, the stone-finished concrete ground floor and the screeded upper floors. The environmental impact of the concrete slab is reduced through the use of recycled aggregates. Insulation is provided externally by 60% recycled glass insulation which is timber clad to the south and rendered to the north.

The cross-laminated structural timber panels were found to be 15% more expensive than a traditional timber stud system. However, set against the shorter programme on site and the higher quality of the finished product, they are a viable alternative to standard construction methods.

House Cavendish Avenue Cambridge

Architect: Mole Architects Ltd (www.molearchitects.co.uk) Structural Engineer: Whitby Bird Quantity Surveyor: Sheriff Tiplady Associates Building Contractor: Cambridge Building Collective Cross laminated structural timber panels: XL solid by KLH (www.klh.at) 60% Recycled glass insulation: Foamglas (www.foamglas.co.uk) Concrete specification (GGBFS): 50% ground granular blast furnace slag

S February Phillips

STUDENT HOUSING UPGRADE Churchill College, Cambridge

Architect: 5th Studio Ltd. (www.5thstudio.co.uk) Quantity surveyor: Gleeds Structural Engineer: Scott Wilson Services Engineer: Roger Parker Associates

Road side: insulating render to maisonette wall

Court side: additional living space, larger windows

This project is a prototype for the future renewal of a 1960’s student family accommodation court which, due to the construction methods of the time, is approaching the end of its life cycle in its current state.

A typical two-bedroom maisonette has been over-clad on the road side with an insulated render system consisting of 80mm rigid phenolic insulation with a render top coat.

The courtyard side has been extended with a timber framed wall structure integrating 150mm insulation with cedar cladding. Here the insulation extends to the interior to reduce the impact of cold bridging from the partially exposed concrete frame and floor slab.

Internal day-lighting has been improved with large

aluminium-framed double-glazed windows and a complete interior fit out has been carried out, including new kitchen, bathroom, lighting and flooring. Under-floor electric heating has been installed together with a mechanical ventilation system incorporating a heat exchanger using heat recovered from the extract air to warm the intake air.

Carrying out the building works to a typical flat within the block has allowed the College to assess the benefits of the design in terms of reduced energy costs. It has also demonstrated how the accommodation can be improved through more generous space planning and allowed 5th Studio to develop a successful model for the potential adaptation of other buildings from this period.

The barns have been reclad and fully insulated

NEW LIFE FOR AN OLD FARM Horningsea

Architect: Granta Architects (www.grantaarchitects.com) Structural Engineer: Gawn Associates Services Engineer: Cambridge Architectural Research Contractor: Kirtling Construction

Imposing living space retains original character

Granta Architects have converted this complex of listed farm buildings into a private residence with an annexe for their offices. The timber structure and cladding of the barns has been left, and restored where necessary, to form the structure and shell for the new house. The walls have been internally lined with 200mm of hemp and recycled cotton insulation and then clad with horizontal plywood boarding which forms the internal finish. Similar timber boarding was used in the building's previous incarnation for storage of straw and food.

A biomass boiler has been installed, in the large utility room, which burns wood chip pellets, a by-product of sawmills, to provide heat for both the under-floor heating and hot water. This is considered to be carbon neutral as trees

absorb the same amount of carbon dioxide during their life as is emitted during combustion. The fuel is currently being transported from Devon for the boiler in this house and for the neighboring property which has a similar heating system.

Due to the nature of the building, a high level of air tightness has been difficult to achieve. However, Granta have skillfully managed to conserve the character of the site whilst producing a sustainable home and office.

Granta employ an environmental engineer in-house one day a week which has enabled them to monitor the CO2 emissions of the complex. This also allows them to integrate energy loss calculations at an early stage into their design processes.

Existing house (rear) has been upgraded

The owners of this large 1950’s detached property have had their house internally remodelled and extended to the front, providing an additional single storey guest suite, with the help of Gavin Langford. This work forms the first phase of a potential three phase project.

The external cladding to the extension is terne-coated steel, a recyclable zinc/tin alloy. The structure combines blockwork and a highly insulated timber frame to give an overall wall thickness of approximately 400mm. The blockwork provides high thermal mass, enabling the extension to stay warmer in winter and cooler in summer for longer than a standard timber framed building.

The front of the existing house has been finished with

Rear view showing upper floor flats

A typical Victorian end-of-terrace shop and flat near the centre of Cambridge has been given a new life. The ground floor shop has been remodelled for AC Architects’ own use. Simultaneously, the building has been extended and raised to the rear relocating the flats at first and second floor levels.

Behind the building, 30 metre deep boreholes containing fluid filled pipes encased in heat absorbing grout supply heat at approximately 11°C to the ground source heat pump which in turn heats the thermal store when the solar panels can not provide sufficient heat.

The thermal store provides hot water to the underfloor heating system. In summer, the building is cooled by cool air drawn by ‘stack effect’ from the basement.

New guest suite extension combines high insulation and thermal mass

lime render, which is more air permeable than a cement base render and allows the bricks and mortar to ‘breathe’ and therefore last longer. A lime rendered wall has also been erected on the road side of the extension, visually relating the new structure with the existing house. The front entrance has been opened up with new glazing and glazed doors have been installed internally to allow more natural light into the front rooms.

The internal re-modelling of the original house includes a new kitchen, family room and floor finishes. Solar thermal water heating and a high efficiency boiler have also been installed, thus helping to up-date and up-grade this family home.

A HOUSE ADAPTED AND EXTENDED Girton

Architect: Gavin Langford (www.gavinlangfordarchitects.com) Structural Engineer: Hannah Reed and Associates Ltd. Services Engineer: Paul Cooper Contractor :Langdon Construction

Street side shop windows conceal ground floor architects’ offices

In order to upgrade the Insulation In the property the brick walls were internally lined with 100-150nn thick phenolic foam Insulation and plasterboard. Most of the doors and windows have been re-used in the new development, in fact the architect, who was also the client, attempted to salvage as much as possible of the existing fabric.

The building’s temperature is monitored by sixteen sensors giving the designers the ability to assess the impact of the various sustainable features and attend immediately to any faults. The sensors do not yet feed back to control the system. However, this will be the next step in up-grading this low-tech but centralised environmental strategy.

A CITY SHOP TRANSFORMED Victoria Road, Cambridge

Architect: AC Architects Cambridge Ltd (www.acarchitects.com) Quantity Surveyor: Henry Riley Structural Engineer, Party Wall surveyor and CDM co-ordinator: Andrew Firebrace Partnership Services Engineer: Conservation Engineering Ventilation design: BP Solar Institute Contractor: Buildmark Construction

RESEARCH

1. Cambridge housing map by predominant date of construction.(Tim Mellor 2004-2008) Pre 1850 1850-1900

1965-2000

1900-1918

1918-1944

1945-1964

2. UK Housing construction date.

(National housing statistics)

Services 18%

Domestic 31%

Industry 25%

Transport 26%

3. UK Energy use as a percentage of total by sector. (DETR 1997)

3% cooking 3% fridge 3% lighting 3% electrical

2% washing 2% misc 24% hot water

60% space heating

4. UK Domestic energy use as a percentage of total by sector. (DTI 2004)

5. Projected modelled CO2 reductions through adaptation of houses by construction date.

6. Cambridge case study house, Hemingford Road.

(Tim Mellor 2005)

CAMBRIDGE HOUSING IN 2080 Predictions from the U.K.’s climatic impacts programme indicate Cambridge is likely to have longer warmer summers, milder shorter winters and more extreme weather events by the year 2080. Summer temperatures in East Anglia may increase by an average of up to 5 deg C for extended periods – creating a climate more akin to Marseille. Tim Mellor, a part-time Cambridge PhD student currently working at RH Partnership Architects in the city is looking at the impact of these climate predictions on our existing housing stock and asks two questions. What are the likely implications of climate change on thermal comfort for existing dwellings? How can existing dwellings be best adapted to maintain thermal comfort in response to climate change?

Cambridge (1), like many other UK towns, is still mainly made up of houses built before the second world war.

Statistics indicate 20 % of our housing was built before the 20th C, 50 % was built in 20th C before the 1973 oil crisis precipitated the introduction of insulation standards (2). Only approximately 30% of our houses were originally designed with insulation in their external walls.

The energy performance of the older buildings is disproportionately poor compared with buildings constructed after 1973 which lends support to the need to review pre 20th C properties first in any programme to upgrade the performance of our housing.

Our love affair with leaky old houses has been sustained by relatively cheap energy prices. At present we use excessive amounts of energy to heat our houses (3 and 4) and increasingly to cool them, due to the inefficiency of the buildings and designs we have inherited from previous generations. In 2003 250,000 new cooling units were purchased for the domestic market in the UK and sales of cooling units have continued to rise steeply contributing 500,000 tonnes of carbon emissions per year to the atmosphere.

Victorian properties are poor at providing insulation due to their solid walls. The walls are lined on the interior with plaster cornices and timber features which are seen as essential components of the character of the property making the introduction of new wall insulation difficult to achieve. Sash windows are generally single glazed and draughty; as much as 30% of the energy use in this type of property is lost through uncontrolled ventilation via leaky sash windows and open fireplaces and chimneys.

At first sight these Victorian properties seem to be a major cause for concern and appear difficult to modify. Tim took a typical, relatively un-modernised terrace house in Hemingford Road (6) as an example and used thermal design software to model the energy performance of the building which was then compared with the actual energy use in the building established from fuel bills and current climate data. The same house was then computer modelled for the predicted climate for Cambridge in 2080. The results of this study indicated the heating load for the house was reduced by 50% in 2080 due to climate change but, more significantly, the period when the house might overheat increased from a few days to most of the summer months from June to September.

The same computer model was used to compare the performance of modern highly insulated timber frame

houses and modern masonry buildings using the predicted climate data for 2080. The results for the timber frame building indicated a significant increase in summer overheating compared with the Hemingford Road House.

Initial analysis of the results indicates that, as the heating season reduces, the importance of thermal mass and other features which mitigate high temperature environments become more critical. In the type of climate predicted for 2080, the Victorian house performs better than expected and offers key features which allow further improvement to reduce the impact of excessive heat.

The Hemingford Road house has relatively high thermal mass which can absorb heat and re-radiate the energy at night The sash window design allows the addition of external shutters to keep the sun out whilst maintaining secure ventilation. Housing types from later periods with outward opening windows make this type of alteration very difficult to achieve. Suspended ground floors might allow secure earth cooled ventilation intakes into the building.

Chimneys might allow secure passive extract ventilation through the houses. The issue of insulation and air tightness will still be important to address, but the summer time performance will increasingly become a major factor in comfort and energy use if Cambridge and the UK is to avoid domestic air cooling units becoming the norm as in the USA.

7. UK Projected temperature changes under differing emissions scenarios between 2000-2100. (UKCIP 2002)

The rate of renewal of our existing housing stock is currently less than 1% per year in the UK. In Cambridge the rate is likely to be even lower as new housing is part of an expansion plan for the city rather than renewal. Building new zero carbon housing in the City is not going to change the performance of the 60 to 70% of existing housing which is likely to still exist in 2080 unless radical alternative policies are adopted for demolition and replacement of the houses which currently define Cambridge’s visual character.

Studies carried out by University College London looking at the future of our existing housing stock concluded that the best option was to demolish and rebuild 2 million pre war homes in the UK. A response by Oxford Brookes University concluded many older buildings were capable of adaptation to meet more stringent energy targets, but still recommended the rebuilding of 1 million homes. The basis for selecting buildings for demolition in our property owning democracy was not made clear. What is clear is the need to set limits for maximum energy use in our existing buildings: however, market forces alone are unlikely to deliver the changes necessary to ensure these targets are met.

As there is unlikely to be the political will to adopt a policy of demolition and renewal, we need to find an efficient and acceptable way to adapt our existing housing.

The debate has only just begun.

Tim Mellor David Emond Alex Reeve

The Three Regions Climate Change Group has recently published: Your home in a changing climate. Retrofitting homes for climate change impacts. This report is aimed at policy makers in the 3 regions of London, the South East and the East of England. For further information go to: www.london.gov.uk/trccg

LETTERS Accordia – flawed paradise?

Your article (CAg 55 – ‘Cambridge contextualism’) on the Accordia housing in Brooklands Avenue mentions that onethird of the dwellings are of the so-called ‘affordable’ type.

However, the text and the pictures refer solely to the extremely expensive houses and flats for sale. Given that ‘affordable’ housing is one of the big issues of the moment, the failure to discuss it is an astonishing omission.

When we moved in to our ‘affordable’ house in Accordia, we were promised a local shop, a playground and a community. It is now clear that there will be no shop, the wonderfully equipped playground (where children and parents of both the well-off and the not so well-off might have mixed) has never been used and is out-of-bounds and there is no ‘community’. Instead, there is a depressing feeling of ‘them’ and ‘us’.

In the 1960s and 70s, huge estates of private and public housing were built – quite separately.

Today, government and local councils are trying to create mixed-income communities by combining houses for sale and ‘affordable’ housing on the same site. So one of the biggest challenges for architects today must be how to combine these in a socially successful way. So far, Accordia doesn’t even begin to work as a community.

Affordable housing at Accordia

Another thing totally ignored by your authors is the quality of construction. In both the affordable housing and, apparently, in some of the expensive housing completed at the time of your article last year, defects were common.

Indeed, the situation was so bad that many of those who live in the ‘affordable’ housing asked the controlling association for a transfer. The official responsible for liaison between the tenants and the builders gave up and moved elsewhere – and we wished we could follow him!

The article concludes: ‘… “it is the architect’s duty … to make paradise for man”. To a considerable extent the architects have achieved this venerable injunction in Cambridge. For those privileged to live in this magnificent celebration of the modern, its spatiality, communality and privacy, for them the ideals of Le Corbusier, Aalto and Martin have been brought together.’

I am aware of the ideals of Le Corbusier but I can assure you that Accordia is no paradise for those who live in that part of the development which your authors completely ignored.

M. Abeysuriya Cambridge Cambridge planning The redevelopment of the Cattlemarket area was very necessary. Its replacement, the well attended new Cambridge Leisure Park, clearly satisfies a need. Living, as I do, close by, I passed the site almost daily as the buildings went up. As a designer, I kept hoping for a pleasant surprise – but none came.

Among other requirements, new buildings are required to demonstrate ‘design excellence’. I visited the Guildhall to find out how this was judged and was told by a Councillor that it was all a matter of opinion.

It seems that decisions are made without reference to, say, a panel of persons qualified to make design judgements.

Brian Human (CAg 55 – ‘A planner’s beef) is brave

enough to admit that the Leisure Park has its failings. But might it not be possible to make the open space more enclosed, more cosy, with some wonderful focal centre and a child-friendly area?

A new challenge facing the planners is the regeneration of the train station area. May we hope that the station services and facilities will be improved, that we shall no longer have to queue in the rain for taxis and that both the bus interchange and the access route to and from the station will also be under cover? Surely nothing less will do for the twenty-first century.

And may we have some fun feature to welcome passengers emerging from the station?

The proposed two-way traffic in Station Road will cause increasing problems. Has proper consideration been given to making it one-way, towards the station, where vehicles may then fan out in several directions?

Tom Karen Cambridge

PROFILE MASONRY MAN Philip Cooper describes himself as a ‘typical Puritan engineer’. He talked to Peter Carolin.

The view of the City’s Design and Conservation Panel is sought by the City on selected projects. There is, however, no obligation on the Planning Committee to reflect this in the decision-making process. With regard to the Station area, the current proposal is for unprotected access to bus and taxi areas and for two-way traffic (with cycle lanes) in Station road. The Editors Graham Pollard 1929-2007 Gazette readers will be aware of the City Council’s Design and Conservation Panel, on which – along with national and local heritage bodies, town and landscape planners and other professionals – the RIBA is represented. Our main job is to vet new planning applications of import or sensitivity within the City boundaries, and to pass informed guidance on each to the Planning Committee.

Graham Pollard, who died in December, aged 78, was a founder member of the present Panel and chaired its predecessor, the Listed Buildings Panel.

He knew Cambridge inside out and, despite representing the Cambridge Antiquarian Society, was as good on new buildings as on old. He set himself high standards of comparison, having for 50 years explored Italy’s cities with passionate curiosity.

His Italian wife, Maria, was crucial to his rise to world authority in the field of Renaissance medals; an advance copy of Pollard’s crowning work – the catalogue of Italian medals in the National Gallery of Art in Washington – reached them in their last weeks.

His formal career of 41 years was in the Fitzwilliam Museum. From 1969 he was Assistant Director, first to Carl Winter, then to Michael Jaffé. He was a Fellow of Wolfson from 1967 and Librarian there from 1980 to 1995. His early retirement (in 1988) from the Fitz was the Panel’s gain.

I only encountered Graham – despite having been, in the 60s, a Jaffé pupil – at Panel meetings, or on his bike. But we had been on the same side in the Kite and Lion Yard campaigns; in the latter, he did much to mobilize the Cambridge Preservation Society against the scheme. And I now know that, in different Cambridge buildings, he and I share the experience of being in a room when a bulldozer blade slices through the wall: in Graham’s case, in his studioroom in the last thatched cottages in inner Cambridge, across from the Maypole. You’ll doubtless have parked above the site.

Passionately but politely nailing ruses and “disgraceful” submissions, or praising what he saw as good, he would frequently marshal his fellow Panel members towards a plainly expressed viewpoint. When Graham Pollard spoke his mind, you sat up and listened, whatever your discipline; he was the Panel’s Mr Valiant for Truth.

To this engaged and articulate layman the Cambridge built environment owes a debt accumulated over 40 years. I am grateful for the opportunity to salute him.

Jon Harris Cambridge

Letters should be sent – by Email, if possible – to the Editors at the address given at the foot of the back cover. The Editors reserve the right to shorten letters.

‘I’m concerned about embodied energy and the lifetime of a building structure,’ says Cooper. ‘With short-life buildings, the embodied energy is a very significant proportion of total lifetime energy consumption. With long-life buildings it’s the longevity of the material which is the issue.’

Unreinforced masonry is Cooper’s favourite material. ‘It lasts a very long time but it can’t carry tensile forces so you have to pre-compress it or use a lot of weight, as in a Gothic cathedral.’ Which brings him onto the subject of permanence. ‘ I’ve always been interested in making permanence – I prefer it to the temporary.

Permanence in the built environment is one of the planks of infrastructure – guiding, ordering and civilizing the population.’

Famous for his sketching skills, Cooper read Engineering at Leeds but, fascinated by architecture, came to Cambridge’s Martin Centre to work in its New Towns Group. He was subsequently a structures Lecturer in the Cambridge Department of Architecture and, at one time, Professor of Architectural Engineering at Leeds. All his practice has been from a Cambridge base, running the local office of Harris and Sutherland and, following a series of takeovers, those of Babtie, Cameron Taylor Bedford and, now, Scott Wilson.

Cooper engineered the elegant bridge across the Bin Brook in MJP’s Burrell’s Field development. And among the many buildings he has been involved in are Tim Ronalds’ Ilfracombe Pavilion, the new Allies and Morrison planetarium at Greenwich and the Pine Calyx conference centre near Dover – an exquisite demonstration of Catalan vaulting.

One of his heroes is Rafael Guastavino, the Catalan who built the Cathedral of St John the Divine in New York City. When, years ago, Cooper discovered Guastavino’s 1893 book, Cohesive Construction, he was hooked.

With the aid of a tile and a sketch pad he starts explaining how Catalan vaults are constructed without any form of shuttering and with the simplest and most elegant forms of setting out.

And highly sustainable, too.

Cover illustrations, clockwise from top left: Wychfield student housing (L) Riverside bridge (News) House in Girton (S) House in Cavendish Avenue (M) Cambridge Forum for the Construction Industry events For details and tickets contact: www.cfci.org.uk secretary@cfci.org.uk Cambridge Association of Architects Annual Exhibition of work.

16 June – 5 July Michaelhouse Centre, Trinity Street, Cambridge (Public lecture to be announced) CA gazette list of current sponsors 5th Studio ACA Architecture Andrew Firebrace Partnership Anonymous Cambridge Forum for the Construction Industry Cowper Griffith Architects Davis Langdon Gavin Langford Architects Gleeds Granta Architects Hannah-Reed Mole Architects Nicholas Ray Associates Purcell Miller Tritton RH Partnership RMJM Saunders Boston SMC Covell Matthews Wrenbridge

RIBA Cambridge Architecture gazette is a review produced by the Cambridge Association of Architects, the local chapter of the RIBA. The views in this gazette are those of the individual contributors and not of the Association. The Editors welcome readers’ contributions but reserve the right to edit Back issues from no. 51 (Winter/Spring 2005) may be found by searching for Cambridge Architecture gazette at: www.architecture.com ISSN 1361-3375 This issue edited by: Anthony Cooper Bobby Open Adam Peavoy February Phillips Zoe Skelding Fundraising by: Marie-Luise Critchley-Waring Editorial Group: David Raven Jeremy Lander Peter Carolin John Preston

Cambridge Architecture gazette c/o 25a Hills Road Cambridge CB2 1NW Tel 01223 36555 Fax 01223 312882 Email jl@frrarchitects.co.uk or mail@draarchitects.demon.co.uk or pc207@cam.ac.uk Printed by Bulldog Publishing Ltd, Whittlesford