UEA Enterprise Centre adorned in thatch.

PHT Patron members Adapt Low Carbon Group, and Architype, the University of East Anglia (UEA) and main contractor Morgan Sindall, have been the driving force in the Enterprise Centre’s low-carbon aspirations, which is striving for stringent certification to achieve both Passivhaus and BREEAM Outstanding, designed to a lengthy 100-year performance life span.

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 is demonstrating that locally sourced materials can perform as well as, or better, than regularly imported materials. This approach is also introducing an alternative design aesthetic that is genuinely local and reflecting vernacular.

ECOLOGICAL MATERIALS:

A thatch hat & coat:

• The thatch facade is a contemporary response to traditional thatching.
• A vast thatch roof and cladding dramatically extends across each face of the building. Thatch is a carbon-negative material that sequesters CO₂ employing easily sourced and rapidly renewable crops alongside simplified processing and close proximity to the site.
• The reed roof is sourced from Woodbastwick on the edge of the Norfolk Broads and Saxmundham’s RSPB Dingle Marshes, Suffolk, and is expected to last for the next 70-100 years.
• As the first technique of its kind, Architype, Morgan Sindall and the thatchers worked together to develop a 1.2m x 1.3m slide-in pre-fab, spruce plywood cassette design to house the panels of thatch which lock together on a seamless split-baton system. Each cassette weighs 40kg, providing the ultimate robust low-embodied carbon rain screen. 
• The thatch will weather to a rich black/brown patina that will characterise the form of the building.

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! Stephen Letch. Leader of The Enterprise Centre’s thatch team, & Chairman of the National Thatching Straw Growers Association.

Domestic timber fighting back against its European rivals:

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. 

• The completed timber frame resulted in 70% of the stud-work being Corsican Pine, sourced from Thetford Forest, 30 miles from site, with the remainder, Sikta Spruce, accrued from within the British Isles. Local timber was sourced wherever possible, overcoming the region’s limitations in structural timber production.
• Larch glu-laminated columns, from Suffolk woodland, support the east-facing canopy & entrance of the building.
• Lift shafts formed with cross laminated timber (CLT) and the overall frame has been completed with OSB board sourced from within the British Isles.

Is there such a thing as eco-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 70% GGBS.
• Reclaimed sub-base material from a nearby demolished hospital building has been used underneath the slab. The slab sits on a bed of strengthened interlocking polystyrene, isoquick. This inert insulation is the beginning of the robust thermal envelope,  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.

 

Non-toxic internal finishes:

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.

• 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 soundboards specified throughout.
• Recycled car tyre flooring provides 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.
• Linoleum, made in Scotland from a mix of linseed and hessian matting, sits on a bed of recycled glass screed and recycled rubber acoustic separation lining.

On completion the net embodied impact of the finished building will be less than 500kgCO₂/m² over the entire 100 year life cycle. A similar University building built to ‘best practice’ standards, can expect to have emitted 800-900kgCO₂/m by the first day of occupation.

 

Further Information:

Architype

Previous PHT Story: University giants battle for largest UK non-residential Passivhaus - 25 November 2014

26th February 2015

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