The embodiment of low carbon

Now nearing completion, the University of East Anglia's (UEA) most recent development, The Enterprise Centre, is on course to become an exemplar low-embodied carbon buildinq, pushing the boundaries for sustainable architecture. The Enterprise Centre will provide a hub to nurture the growth of small and start-up businesses. Sustainable in every sense, the centre will be the first large scale commercial building to achieve both Passivhaus and BREEAM Outstanding in the UK.

The Adapt Low Carbon Group has created The Enterprise Centre, which will be the UK's greenest commercial building meeting the highest BREEAM and Passivhaus standards. Adapt brings together a broad range of expertise and builds on the widely acknowledged successes of the University of East Anglia's (UEA) business activities in the low carbon sector. Adapt Low Carbon Group and the UEA, have been the driving force in this unique building's low-carbon aspirations which, besides striving for stringent certification, have also put huge emphasis on the sourcing of local and East Anglian materials; an interesting and challenging aspect of this build. Adapt Low Carbon Group has worked alongside construction and infrastructure company, Morgan Sindall, the single point deliverer on the enterprise centre and architects, Architype. to ensure these challenges have been met. Materials have been sourced, fabricated, tested and implemented from as close to site as possible, with the balance being procured from elsewhere in the UK, severely reducing the building's imported materials.

The project team's commitment and determination to specify locally and domestically has unearthed new potential for UK architecture, demonstrating that locally sourced materials can perform as well as, or better than, regularly imported materials. Besides being functionally appropriate, this approach introduces an alternative design aesthetic that strives to be genuinely local, reflecting upon the surrounding vernacular, and embedding the building in its regional context.

From the foundations up of this pioneering building, local material is plentiful in the initial supporting structures; with the concrete slab comprising a mix of low carbon elements that address the ecologically controversial ingredients of concrete. Recycled steel forms the integrity of the slab and is accompanied by locally sourced aggregate and a cement replacement, ground granulated blast slag (GGBS); a sustainable by-product of the steel industry that improves the durability of the concrete with increased ratios, for which this building reaches the upper-echelons of 70% GGBS. Additionally, after researching local demolition schedules and discovering a nearby hospital building due to be razed, the team negotiated reclaiming the sub-base material, which has formed the sub-base underneath the slab. In support of this, the slab sits on a bed of strengthened interlocking polystyrene, lsoquick. This inert insulation is the beginning of the robust thermal envelope, or 'duvet layer', which is essential to the Passivhaus requirements. On site, Morgan Sindall collected the off cuts, returning them to the supplier where it was recycled into new Isoquick, creating zero waste.

Local and domestic materials continue to feature in the various components of the timber frame, following two years of meetings and negotiations between the Forestry Commission, local suppliers and various key players in the East Anglian timber industry. The design team in collaboration with timber frame contractors, Cygnum, worked to secure local timber wherever possible, overcoming the region's limitations in structural timber production. The completed timber frame resulted in 70% of the stud-work being Corsican pine, sourced from Thetford

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Forest, 30 miles from site, with the remainder, Sikta spruce, accrued from within the British Isles. From the same Suffolk woodland comes the celebrated larch glulaminated columns, as showcased in the salient east-facing canopy of the building. forming a dramatic entrance that is a telling introduction to the centre's materiality. The commitment to low-embodied materials is carried all the way through to the lift shaft, formed with cross laminated timber (CLT). and the overall frame has been completed with OSB board sourced from within the British Isles.

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It's great to see domestic timber specification fighting back against its European rival. Often underestimated for its capabilities as a structural component, British timber can sometimes be discounted for its fast-growing nature and comparatively lower yield. Though true, these traits show no influence on the integrity of the timber when used for structural components, a fact ever prevalent in The Enterprise Centre, which has been designed to a lengthy lOO-year performance life span. This unique project is proof of the possibilities for home-grown timber and also opens a conversation for supporting and developing this industry. It was not economically feasible for all elements of the timber frame to be sourced domestically, with the I-beams imported from North America, and the internal glulams Austrian. However, that is not to say that these are not tangible aims for future projects. The Enterprise Centre hopes to be at the foot of promoting the use of UK timber products in construction and closing the gap on overseas' imports.

Visually, the most outstanding and spectacular contribution to the material palette is realised in the vast thatch roof and cladding which dramatically extends across each face of the building. The use of thatch epitomises the project team and clients' visions for The Enterprise Centre, linking the notion of local supply chains with prominent and famed East Anglian materials such as reed and straw. Thatch is a carbon-negative material, the perfect technique to complement this low- carbon building, employing easily sourced and rapidly renewable crops, alongside simplified processing and close proximity to the site.

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The reed roof is sourced from Woodbastwick on the edge of the Norfolk Broads and Saxmundham's RSPB Dingle Marshes, Suffolk. Although, on a much larger scale, the installation of the thatch employs the same tools and principals as used by thatchers for centuries. A team of local thatchers were able to complete the c1erestory roofs across a tight four- week programme, achieving a robust solution for the next 70-100 years for The Enterprise Centre.

The thatch facade is a contemporary response to traditional thatching. As the first technique of its kind, Architype, Morgan Sindall and the thatchers worked together to develop a slide-in cassette design to house the panels of thatch, which lock together on a seamless split-baton system. The cassettes have been a great success, all prefabricated off-site and indoors during the winter months, helping the project to stay on schedule, with the additional benefit of extending the thatching season. Each cassette frame measures 1.2 metres by 3 metres and was assembled by local joiners using spruce plywood.

The thatch infill is a blend of locally procured wheat and straw varieties, mainly comprising 'Foster Special', 'Maris Huntsman' and the local Norwich developed variety, 'Yeoman' wheat straw. Chosen for their slightly shorter stemmed nature than older roofing varieties of wheat, they offer a more tactile and bristly appearance, which compliments the reed roof and makes for a more textured aesthetic. Further to this, the cassettes are prepared differently to a normal finish, with 95% of the straw butt-end being visible, as opposed to the normally softer even mix of butts and ears. Once the thatch is applied in its entirety, each cassette weighs a hefty 40kg, providing the ultimate robust low-embodied carbon rain screen for this innovative building. Through weathering, the thatch will slowly develop over time from the fresh cut golden colour to a rich smokey black/brown patina that will characterise the form of the building.

Stephen Letch, long standing member of the East Anglian Master Thatchers Association, Chairman of the National Thatching Straw Growers Association and leader of The Enterprise Centre's thatch team, has facilitated much of the procurement and implementation of this epic project. He says; 'This project is both challenging and exciting for the team of thatchers, however the team felt that this project was well worth our effort, to promote the positive benefits of thatch in new construction such as longevity, breathable insulation, sound deadening qualities and exceptional green credentials. For the team of thatchers the project is our chance to reclaim back at least some of our future that was taken away from our 19th century thatcher ancestors by the carbon hungry construction industries, this is our mission!'

As if the low-carbon credentials of this process were not enough, Stephen has also been able to make use of the wheat's scrap off-cuts, turning this by-product into flour and wheat beer!

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The mixed palette of the east-facing courtyard is a plethora of sustainable materiality that plays to the senses; from the Thetford Forest larch glulams, to Norfolk broad thatch and the locally sourced flint shingle used in the fittingly designed landscape. The canopy's soffit and south facing rain-screen cladding, have been reserved for new material experimentation, clad with external grade MDF; a cost effective and low-carbon alternative to external finishes. This is just one of the specifications to be trialled on this pioneering project.

Above the entrance are striking panels of sawn and plained African Iroko, recycled from old lab desks that were recovered from the University's chemistry building, designed in the 1960s by iconic architect, Denys Lasdun. With the species recently confirmed by the original project architect, Gordon Forbes, this find presented a rare opportunity to use exotic high-grade timber in a sustainable way. The remainder of the cladding, and the most recent acquisition on-site, is a haul of twenty-year-old seasoned oak, sourced from a local timberyard who sited the oak's origins from the Holkham Estate, North Norfolk.

In a similar vein, reclaimed from the renowned on-campus Sainsbury Centre, an original Norman Foster designed reception desk is the focal point of The Enterprise Centre's entrance foyer. These resourceful and creative elements embrace the University's rich past and inform visitors and users alike of the forward thinking and sustainable future of The Enterprise Centre.

Seeing all of these local and innovative materials juxtaposed externally is telling of the authenticity and commitment to specification of the design team. It also provides an impressive visual and physical gateway to the continuing palette of the interior. The high levels of internal comfort provided by the Passivhaus requirements of this building are complemented by a range of ecological and non-toxic finishes that make for a healthy atmosphere, aiding wellbeing and focused study and work. Heavily influenced by lead architects, Architype, the interior specification includes a number of tried and tested finishes frequently employed by this sustainable, design-led practice. The timber slatted ceiling makes use of low-grade softwood, enhancing the natural palette and contributing to the acoustic quality of the spaces, as realised with the wood-wool acoustic sound-boards specified throughout.

Another material trial of the building is an acoustic and finishing treatment, which has been used in the roof wings. As a spray on cellulose product, the formed layer is made from 85% recycled waste paper, which although produced in the US, looks to be manufactured soon in the UK following positive feedback of recent applications. Recycled car tyre flooring provides a robust solution to areas of heavy footfall, whilst coatings are all solvent-free, with natural based paints and vegetable-based oils.

Dry internal wall linings, made in the Midlands, provide a blank canvas for the range of tactile, natural wall coverings, that eliminate off gassing and contribute to the fresh atmosphere and subtle design aesthetic of the interior. Nettle fabric, earth board, locally sourced reed boards and a rustic hemp and lime render, lead the interior pallet with a colourful range of textures, used to distinguish and identify the individual pods on the first floor.

Restrictions in the budget called for a change of plan to the ground floor finish. Unable to complete the majority of the ground floor with the preferred option of timber flooring, an alternative was sought, delivering a diamond ground concrete finish. Producing a great quality, low embodied carbon result, due to no replacement over the building's lifespan, the diamond grinder makes a fine and consistent high quality surface. Elsewhere in the building, linoleum, made in Scotland from a mix of linseed and hessian matting, sits on a bed of recycled glass screed and a recycled rubber acoustic separation lining.

The meticulous specification of The Enterprise Centre has been essential in achieving the ambitious low-energy credentials that the project team have striven for. On completion the net embodied impact of the finished building will be less than 500kgC02jm2 over the entire 100 year life cycle, astonishingly low when compared to a similar university building built to 'best practice' standards, which can expect to have emitted 800-900kgC02jsqm by the first day of occupation.

Local specification has not only contributed the low-carbon BREEAM credits, it has inspired and enhanced the desiqn of The Enterprise Centre, using limitations positively, culminating in a striking yet honest appeal that will both complement the local vernacular and assume its own identity on the UEA campus and within Norwich.

Finally, and perhaps one of the greatest achievements of this local approach has been the critical involvement of local suppliers, whose expertise, resources and skill-set have influenced the overall design and solutions of this one-of-a-kind building, reinforcing The Enterprise Centre's key purpose of enhancing commercial relations and working together to achieve sustainable solutions.

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Story and photos provided by Architype on behalf of the Adapt Low Carbon Group.

Further information

Architype is a recognised leader in the development of sustainable architecture in the UK and has been responsible for many innovations, involving both architecture and materials. Founded in 1984, the practice now operates from two busy offices in London and Hereford, and is currently working on a range of projects across the UK and abroad. WWW.ARCHITYPE.CO.UK

The Adapt Low Carbon Group now offers construction site tours of The Enterprise Centre, together with a range of other workshops and one-to-one support. These tours are led by Adapt's Centre for the Built Environment and are free to small and medium size businesses. For more information about upcoming seminars and site tours, please visit: WWW.ADAPTCBE.CO.UK/CBEIEVENTs

The Adapt Low Carbon Group is delivering EU projects worth over £75m with the backing of the European Regional Development Fund. It also offers consultancy to businesses which are looking to save money through reducing their impact on the environment. Any profit is returned to UEA through gift aid. The Enterprise Centre has been funded by the University of East Anglia, Norwich Research Park, European Regional Development Fund, BB5RC and BRE. For more information, please visit: WWW.ADAPTLOWCARBONGROUP.CO.UK

Morgan Sindall is a UK construction, infrastructure and design business with a network of local offices. The company works for private and public sector customers on projects and frameworks. Visit: WWW.MORGANSINDALL.COM

The Biotechnology and Biological sciences Research Council (BB5RC) invests in world-class bioscience research and training on behalf of the UK public. Its aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve the quality of life in the UK and beyond. Funded by the government, BB5RC invested over £484M in world-class bioscience in 2013-14. Visit:

WWW.BBSRC.AC.UK/INSTlTUTES

Story and photos provided by Architype on behalf of the Adapt Low Carbon Group.

‘ The embodiment of low carbon’, Green Building Magazine , Spring 2015, Volume 24, No. 4 , pg. 30-34