structural design solution (year 2) 1st semester

Barton Visitor’s Centre Structural Design Solution

BY KINTU ALVIN University of salford Student ID: 00602998 Course name: Construction & Technology Professor: Ric Frankland Due Date: 26th November, 2021

About the Visitors centre The Barton visitor’s centre located in Barton airfield is meant to serve as a public space to the community whilst maintaining cultural heritage aspects of the site environment through self-identification to existing building typology around the site. As a public centre the project covers a range of spaces relevant to the public as evidenced in different precedent studies through considering common spaces used. Namely a learning centre, an exhibition space, a food space/café, storage room, a gift shops an observatory platform for plane watching and site seeing and last but not least washrooms.

For purposes of inclusion the project is designed to cater for all groups of people with safety at the forefront therefore being restricted to a ground level with open rooms. Thus, promoting socialism and easing circulation from one place to another.

The aim of the project is to provide an eco-friendly sustainable space to the community through careful consideration of different structural design qualities for both substructure and superstructure. Such as. o Thermal performance and control of moisture in structural fabric. o Fire performance strategy. o Buildability. o Aspects of modern methods of construction and design for manufacture and assembly. o Sustainability relating to greenhouse gas emissions. o Review of approved documents ‘building regulations.’

Structure design solutions In order to develop a low-carbon structure, it is important to consider different design solutions for different part of the structure namely substructure and superstructure. This will as well include both building fabric materiality and as thermal performance & control moisture strategy, (2) fire performance strategy, (3) buildability and lastly aspects of modern methods of construction and design for manufacture and assembly. This will be done through different a comparison processes.

modifed and adopted from Ching, 2020.

Identification of major materials For purposes of sustainability selection of materials is vital to the project as it essential to keep the level of C02 emissions low both at construction level and operational level.

As noted in UK Green Building Council article published in 2018 by Johanna Lehne a research associate at Chatham house. It stresses the need to reduce carbon emissions by 50% in the built environment whilst providing alternative materials to high carbon materials such as traditional concrete & cement (UK GBC, 2021). Blended cement and concretes that store carbon by the DB Group ‘cemfree concrete’ (DB group, 2018). It is highly resistant to chemical and frost action as per requirments by NHBC standards.

(NHBC, 2021, DB group, 2018). Other materials include wood, hempcrete, strawbales, and mycelium are some of the materials that are given as alternatives despite of scarcity of some materials such as hempcrete, strawbales and mycelium (UK GBC, 2021).

This renders wood and concrete and wood as alternatives for the project. However, for purposes of minimising both embodied carbon and operational carbon it is worth taking note of both the advantages and disadvantages of each material before selected for use to attain retain structural efficiency.

The aim is to gain an understanding of the two materials to be used in the structure and where they can be used in the structure as a structural solution for both substructure and superstructure.

adopted from DB Group, 2021 https://dbgholdings.com/cemfree/

adopted from Hitchcock & King https://www.hitchcockandking.co.uk/h-k-news/is-timber-environmentally-friendly/

Advantages of selected materials (GIATEC.com, 2021) 1. Wood • Light and easy to work with during construction.

• Inexpensive to attain.

• A natural resource therefore inexhaustible.

• Is a biodegradable material after use.

• Stores carbon 2. Traditional Concrete • Has a longer life span therefore rendering it highly durable.

• Involves low maintenance costs.

• Does not rot, burn or rust.

• Absorbs and retains heat when used as a unit.

• Highly resistant to wind and water.

• Concrete is a non-combustible material.

• Highly effective material for sound proofing.

Disadvantages of selected materials. (GIATEC.com, 2021, NHBC, 2021) 1. Wood • Undermines structural integrity due formation of molds over a period of time.

• Wood is highly susceptible to termites, decay, water damage and fire damage as cavity barriers, fire stops and services have to be taken into account.

2. Traditional concrete • The cost of making concrete is costly both environmentally ‘high carbon emissions’ and economically.

• Heavy and difficult to transport.

• Limited versatility.

• Delays construction due to a lengthy drying process.

• Concrete is highly susceptible to efflorescence.

• Concrete is a non-biodegradable material hence increases embodied carbon emissions.

adopted from https://www.bbc.co.uk/news/science-environment-46455844

timber precautionary measures adopted from NHBC Standards, 2021 https://nhbc-standards.co.uk/

adopted from DB Group, 2021 https://dbgholdings.com/cemfree/

However, due to the desired project outcomes the intention is to use cemfree concrete as a solution to mitigate the negative impacts of traditional concrete so for the project this is due to the following reasons (DB group, 2018).

• cemfree concrete has a lower carbon emission by 73%.

• Reduce resource exhaustion in with concrete is manufactured through cement substitution with an alternative industrial-by product.

• Higher levels of durability than traditional concrete.

• Is easily accessible throughout the United Kingdom.

• Highly suitable for load bearing loads, foundations, internal walls and cavity walls.

• Compliable with Health and safety Executive regulations since it is made from class 1 aggregates.

For the above reasons stated, cemfree concrete is a suitable alternative for traditional concrete as it retains the best aspects of it and is therefore more sustainable. However, this may as well be limited to only the foundation since it is not entirely carbon neutral ‘73% decrease’ compared to timber/ wood but provides a strong foundation the structure ‘substructure’ whereby wood imperfections are easily resolved through structural design strategies, procurement and following of manufacturer recommendations (DB group, 2018, GIATEC.com, 2021).

Wall systems Timber frame vs steel and concrete frame A timber frame structure is made up of diagonal bracing or shear panels that provide are meant to provide lateral stability qualifying as heavyy timber construction when used with non-combustible fire resistive external walls on condition the minimum size requirement in the building code is meant by its members while steel and concrete frame span greater distances, carrying heavier loads than timber (Ching, 2021).

Why timber frame and not steel and concrete frame?

The intent is to utilise a timber frame structure in the visitor’s centre as timber easily absorbs carbon unlike steel framed structures whilst typically having a better thermal performance than structures containing concrete. This is made possible by low thermal mass that enables spaces enclosed by timber to heat faster. (building design, 2021) Other reasons include increased speed of construction whereby construction can be carried out in low temperatures unlike masonry that requires warm temperatures for construction to take place (building design, 2021).

• Timber frame constructions can easily be fabricated off -site and in more controlled conditions and assembled when ready unlike steel and masonry framed structures thus increase in quality of work and speed of work (building design, 2021).

• Acoustic performance of timber framed structures can easily be adjusted to desired performance (building design, 2021).

• The cost of transportation is relatively lower than steel and masonry structures which require more transportation input therefore increasing the carbon footprint of a structure (building design, 2021).

In order to have fully exploit the benefits of using wood over concrete aspects such as wall insulation, wood type for both floor and walls have to be considered. This is to control the thermal performance of the building fabric in the super structure.

adopted from ibuild building solutions. https://i-build.com.au/knowledgebase/steel-or-timber-frames/

https://steemit.com/features/@echomi- https://icon-icons.com/icon/gui-shiplowy/check-out-new-upvoting-sound- ping/157590 effect

https://www.dreamstime.com/ wood-material-sawmill-industry-vector-icon-design-white-background-wood-material-sawmill-industry-vector-icon-design-image179355239

photographed by JackHobhouse https://www.trada.co.uk/news/wood-awards-2020-winners-announced/

adopted from Trada, 2021 https://www.trada.co.uk/news/wood-awards-2020-winners-announced/

Selection of wood type to be used on wall.

As seen in wood award winning projects 2020 such as The Rye Apartments located in London by Architectural practice Tikari works, Frindsbury Manor Barn located in Rochester by The Heritage Design and development team are projects the give purpose to the use of wood as both projects are based on the principle of environmental conservation (TRADA, 2021).

Both using Austrian spruce and British oak respectively which can as well be used in the visitor’s centre project (TRADA, 2021). However, with sustainability at the forefront, British oak is a better alternative as it grown in British soils unlike Austrian spruce tree that is not grown in foreign soils (Wikipedia, 2021). Thus, lower operational carbon emissions.

Why oak as the main structural frame.

• • • • • •

Durable as it does not require treatment for external use (greenspec, 2021).

Is categorised under hardwood and is often available with FSC certification (greenspec, 2021).

Lasts for a long period of time between 40 to 60 years (greenspec, 2021).

Is home grown in the UK and can also be exported from Europe hence easily accessible (greenspec, 2021).

Oak is hard-wearing, and it’s often rendered resistant to impacts (greenspec, 2021).

Contains natural properties that renders it highly resistant to insects (design buildings, 2021).

Thermal strategy Table 1 shows different the different materials different insulation forms can be presented in when used in a project to provide thermal insulation in different parts of a structure. It demonstrates that polyurethane insulation not being highly combustible when exposed is highly toxic to individuals during application despite having a good R depending on the material. Therefore, not being ideal for use in the visitor’s centre.

However, it demonstrates fibreglass insulation is suitable for studs, joists, rafters whereas rockwool insulation is also incombustible hance making it suitable for wall insulation. Thus, applicable for use in the visitor’s centre due to their benefits over polystyrene and usable R-values.

adopted from Ching, 2020.

External wall insulation or Internal wall insulation

Why external wall insualtion? (Back to earth, 2018) • External wall insualyiion is more apropriate since their is less risk of cold bridging compared to internal wall insulation.

• Provides better thermal performance throughout the day. thus lower green house emissions.

Floor systems The main three types of floor structures include concrete, steel & wood floor structural systems. These help create a link between a substructure and a superstructure. (Ching, 2012) Why concrete floor over wood floor Concrete floors require less maintenance than wood floors.

This due to the level of durability of concrete floors compared to wood especially in public spaces (floorcrtics, 2021).

The cost and time of installation of concrete floors islessthan that of wood floor installation and maintenance (floorcrtics, 2021).

Concrete floors last long than wooden floors over a period of time (floorcrtics, 2021).

Wood floors pose a higher safety risk namely raised edges easily trip individuals walking by and slippery when wet unlike concrete that is only slippery when wet thus a lower safety risk (floorcrtics, 2021).

Cemfree concrete stores carbon unlike tradition concrete thus making it possible to use concrete without worrying about carbon emissions (DB Group, 2018).

adopted from Ching, 2020.

Slab type varitaion Why hallow concrete slabs?

Benefits of using concrete hallow slabs over solid concrete slabs for flooring. (IPHA, 2021, NHBC, 2021)

adopted from Ching, 2020.

• Eases installation of structural service systems • Is light weight thus increased mobility during transportation and installation.

• More efficient and sustainable since it requires less material and spans over longer sections compared to solid concrete slabs.

• Can be made to desired requirements off-site to due to ease of transportation facilitated by its nature.

• Contain better thermal characteristics than solid slabs thus lower energy consumptions.

• Achieve all accepted standards of and design requirements for fire resistance in a building.

• Have higher superior sound insulation in residential structures compared to solid slabs.

• Has adequate strength and thickness (100mm) to carry load baring walls.

Roof systems Flat roof vs pitched roof • • • • • • • • • • • • • • • • •

Advantages of pitched roofs over flat roofs (cupapizarras, 2021) Wide variety of styles and sizes to select from.

Provide more efficient thermal insulation compared to flat roofs.

Promote the use of natural ventilation as the are built to allow ventilation between the outer and inner layer of the building.

High levels of tolerance to external forces such as snow loads, rain, wind and ensure a efficient water drainage away from the building fabric.

Provides space for expansion in the long run.

Longer lifespan as a result of less maintenance costs and maintenance in the long run.

Encourages the use of rainwater thus preventing flood occurrences. Caused by easy collection of rainwater.

Highly levels of sustainability as a result of a wide range of building sustainable building tiles with which green energy can be incorporated.

Advantages of pitched roofs over flat roofs Wide variety of styles and sizes to select from.

Provide more efficient thermal insulation compared to flat roofs.

Promote the use of natural ventilation as the are built to allow ventilation between the outer and inner layer of the building.

High levels of tolerance to external forces such as snow loads, rain, wind and ensure a efficient water drainage away from the building fabric.

Provides space for expansion in the long run.

Longer lifespan as a result of less maintenance costs and maintenance in the long run.

Encourages the use of rainwater thus preventing flood occurrences. Caused by easy collection of rainwater.

Highly levels of sustainability as a result of a wide range of building sustainable building tiles with which green energy can be incorporated.

adopted from Ching, 2020.

warm roof / cold roof

A warm roof is the most appropriate solution for the vistors centre as it provides better insulation performance compared to a cold roof and moisture control as well as being cost effective.

Substructure In Building Construction Illustrated by Francis D.K. Ching shows how anything found below ground level in a building is considered as part of the substructure and is typically composed of the foundation of a building as the base element to give rise to a structure (Ching, 2019).

This can be categorised mainly into two types namely. o Deep foundations o Shallow foundations Both categories typically utilise a combination of bearing walls, columns and piers to transmit building loads directly to the earth/soil depending on the nature of soil and designed to accommodate the layout and form of the structure (Ching, 2019).

This is seen whereby deep foundations are typically used in unstable soils with inadequate load bearing capacity while shallow foundations are often used in stable soil conditions with adequate load bearing capacity and often cost less than deep foundations hence being more suitable for use in the visitor’s centre (Ching, 2012).

adopted from Ching, 2020.

Based on the nature of the structure a shallow foundation is more appropriate since it is easier to construct, accommodates light loads such as the designed visitor’s centre and does not require as much input as a deep foundation.

However, there are different types of shallow foundations such as isolated footing & strip footing one of which can only be selected for the project.

For purposes of following building regulations, a strip foundation is more appropriate due to the availability of data related in the building regulations governing foundations despite of the fact that also a deep foundation can be used.

Superstructure and substaucture sketch details

understanding the structure

1:50 suggested strip foundation paths for proposal to structural engineer recommendation. concrete slab

space between timber frame and external cladding for inclusion of wall layers eg insulation

external cladding

cross bracing timber frame for improved structural stability against external forces such as wind.

1:50 full heaight stip elevation /section a- load bearing continuous shallow foundation strip b- stable earth soil supporting foundation structure c- base course of gravel preventing capillary rise of water (100mm) thickness d- 15mm sand layer placed over moisture barrier for excess water absorption e- polythene moisture barrier f- hallow concrete slab g- timber stud connection joint between sub and superstructure h- plaster covering plywood sheathing i- rock wool insulation j- wood pecking to window head with compressible fill above k- sill board preventing water entry into structural interior l- breathable membrane behind plywood sheathing m- connecting nail used in connection joint

y x w v u t s

oak wood cladding

clay roof tiles

Level 1 3000 l

Superstructure k j

r

q p

i

o n

h

m

g f e d c b

Level 0 0 Substructure

a

n- oak wood exterior cladding against weather conditions o- plywood sheathing p- rigid insulation surrounded with a breathable membrane q- external rigid insualtion r- flashing cover with compressible filler between window and stud work s- 15mm water outlet gap above window t- eave vent to allow circulation in roof structural whilst enabling continous flow of air u- ice and water sheild v- timber connecting joint w- air gap x- clay roof tiles y-plywood sheathing

cemfree concrete for verander

1:50 section through full height of external wall oak wood cladding (unfurnished)

Double glazzed window

cemfree concrete floor

glazed curtain wall

clay tiled roof

glazed roofing system wooden hand rails

Level 1 3000

Level 0 0

Level 1 3000

Level 0 0

1

North 1 : 100

vsV v

Level 1 3000

Level 0 0

2

South 1 : 100

Level 1 3000

Level 0 0

3

West 1 : 100

timber cloumn

cemfree cement block

furnished oak wood panel

traditional concrete block

100mm rock wool insulation

SampleTemplate

Reference list Back to Earth. (2021, 23 November). Is internal or external insulation better. https://www.backtoearth.co.uk/is-internal-or-external-insulation-better/ Barton Roofing Merchants. (2021, 23 November). Warm Roof vs Cold Roof. What’s The Difference? https://www.burtonroofing.co.uk/blog/warm-roof-vs-coldroof-whats-the-difference/ Cupa Pizarras. (2021, 23 November). Advantages of Pitched Roofs. https://www.cupapizarras.com/uk/news/advantages-pitched-roofs/#Thermal_insulation DB Group. (2021, 23 November). Greenbloc Building a Sustainable Future. https://dbgholdings.com/greenbloc/ Designing Buildings. (2021, 23 November). Advantages and disadvantages of timber frame buildings. https://www.designingbuildings.co.uk/wiki/Advantages_and_disadvantages_of_timber_frame_buildings Floor Critics. (2021, 23 November). Concrete vs Hardwood Flooring. https://floorcritics.com/concrete-vs-hardwood-flooring/ Francis. C. (2020). Building construction illustrated (6TH ed). John Wiley & Sons, Inc., Hoboken, New Jersey GIATEC. (2021, 23 November). Wood vs. Concrete: The Best Choice for Builders and GCs. https://www.giatecscientific.com/education/wood-vs-concrete-bestchoice-builders-contractors/ HM Government. (2021, 23 November). The building regulations 2010. The Merged approved documents. https://www.gov.uk/guidance/building-regulationsand-approved-documents-index#approved-documents International Prestressed Hallow Association. (2021, 23 November). Why Hallowcore? https://hollowcore.org/hollowcore/why-hollowcore/ JTC Roofing Contractors. (2021, 23 November). Pitched Roofing vs Flat Roofing. https://jtcroofing.co.uk/news/pitched-roofing-flat-roofing/ NHBC Standards. (2021, 23 November). Substructure and ground bearing floors. https://nhbc-standards.co.uk/5-substructure-ground-floors-drainage-andbasements/5-1-substructure-and-ground-bearing-floors/5-1-17-ground-floor-slab-and-concrete/ TRADA. (2021, 23 November). Wood Awards 2020 Winners Announced. https://www.trada.co.uk/news/wood-awards-2020-winners-announced/ UK Green Building Council. (2021, 23 November). Growing the market for low-carbon building materials. https://www.ukgbc.org/news/growing-the-market-forlow-carbon-building-materials/