Natural materials and an ecological approach at Architype's UEA Enterprise Centre
Proposal using thatch and rammed chalk revealed at this year’s AECB Conference
At the recent AECB conference Architype’s Ben Humphries was joined by Ben Binns, Programme Manager for the Built Environment at University of East Anglia (UEA), to speak about their project; a new Enterprise Centre at the university.
Half of the building will provide lettable floor space for SME start up businesses including offices, meeting rooms and hot desks, with the rest housing teaching and learning facilities for the University. The brief required the proposals to meet Passivhaus standards, achieve BREEAM Outstanding, use a local supply chain of materials and labour, and act as both a carbon sink and a ‘gateway to the university’.
UEA are moving towards more sustainable building on their campus - their Sainsbury Centre by Fosters uses a shocking 24 percent of the campus’ energy. By comparison, the more efficient Sidell Gibson-designed Elizabeth Fry Building, venue for the AECB conference in 2008, is acting as a blueprint for the University’s sustainability goals.
The design for the Enterprise Centre was put out to competitive tender, in just three weeks competition teams had to use set standards to calculate the embodied carbon of the materials and of their proposed buildings, allowing easy comparison between submissions.
Ben Humphries spoke of the challenges the design team were initially to face; in particular the site’s orientation which was not favourable for meeting Passivhaus. Architype’s proposal splits the building into two pavilions; with commercial activities in one wing, and teaching in another, featuring a lecture theatre in a central courtyard.
Despite having difficulties in finding a local supply of Passivhaus windows, as with many UK Passivhaus projects, they created a materials map of what could be found within 90 – 100 miles of the site; hemp, timber, chalk and thatch were most abundant. This makes for the most interesting aspect to the project; locally sourced chalk is being rammed to create the walls of the lecture theatre, heavily inspired by Pat Borer and David Lea’s rammed earth lecture theatre at WISE.
The rammed chalk will be rendered externally to protect it from the elements, but inside the beauty of the material will be revealed. Hemp insulation will be used throughout the building, calculations show that 170 acres of hemp must be grown to provide this, so its lucky the University has its own harvester. The wall construction is anticipated to provide a U-value of 0.11W/m²K at a total thickness of 473mm.
Clad in thatch, the building will have a beautifully textured finish to the façade. Prefabrication of the cladding in local barns means that their construction can be carried out during the winter months, providing off-season work for the thatchers. Architype aims to reinvigorate what could be seen as a dying industry, and prove that the use of such traditional and natural material does have its place in 21st century architecture.
Architype have predicted that the embodied energy of the finished building will be 168 kgCO2/m². A recent study by Atkins shows that the embodied energy of a university building is likely to be around 845 kgCO2/m², suggesting the UEA project’s focused approach to embodied energy has led to a great reduction.
The building certainly creates an aesthetic of its place, reminiscent of the materials which characterise Norfolk and East Anglia. It will be interesting to see the effect of these materials once the building is completed, and how the design develops through the construction process. The building aims to revive the traditional thatching industry of the area, which is achievable if the project is a success, but may be the largest challenge of the whole project.
There will be many lessons learnt from this project, particularly in designing a large Passivhaus building that also meets BREEAM requirements, making for a great seminar at a future AECB Conference. However, the question remains; will thatch ever become a mainstream building material? And how will its prefabrication techniques develop after the completion of this project? Only time will tell.
Main Contractor: Morgan Sindall
Structural Engineers: BDP
Building Services Engineers: BDP
Landscape Architects: Churchman Landscape Architects
Soft Landings: BSRIA