
A competition created to explore the issues arising from the introduction of the Code for Sustainable Homes has revealed new concepts and ideas that challenge assumptions of carbon neutrality. The competition, Carbon Challenge 2007 – the second in a series of annual design competitions held at PRP to respond to industry issues – shows new approaches by PRP’s architects that include embodied energy and solar gain, currently not part of the calculation of carbon neutrality. Many of the schemes also acknowledge the importance of generating renewable energy for a wide area rather than relying on micro-generation, an implication of Code level 6* and much current planning policy.
PRP director, Andy von Bradsky, said: “Our competition has come at a timely moment in the architecture of housing. All new homes in England are to be carbon neutral by 2016. Now that the challenge of zero carbon homes has reached the mainstream housing marketing, bearing in mind that the sector is notoriously conservative in terms of the homes they offer, we set out to explore whether low or zero carbon homes had to look different, and if accepted principles of good urban design, like place making, safety, legibility and privacy, had to change. We wanted to see how our architects would respond to the challenge, what technologies they would embrace, what the architectural language might be and how the site would be laid out.”
A total of 8 entries were submitted from across PRP’s multidisciplinary practice. Interestingly, a number of common themes emerged alongside some unique concepts, including:
Consideration of the wide area context in terms of energy generation and supply through new infrastructure
Wind turbines and CHP fuelled by bio-gas or bio-mass sourced locally
Need for flood defence and storm water storage combined with grey water recycling on a site-wide basis
A neighbourhood approach to issues to car pooling, community facilities and workspace to address social and economic sustainability as well as environmental sustainability
Incorporating devices and methods that encouraged a change in lifestyle of the occupants – such as real time data systems
Incorporating live/work accommodation to reduce car usage, the single biggest contributor to people’s carbon footprint
Sourcing local food or facilitating farmers’ markets for locally grown food and orchards within the developments
Linkage with farms for bio-gas production
Adaptive house principles for future flexibility
Use of heat pumps, solar heating, photovoltaics and wind turbines on house types as a supplement to the area wide renewable energy generation
Use of natural materials such as rammed earth and timber frame Trombe walls for heat storage and transfer
Passivhaus principles for the building fabric to minimise heat loss
Passive stack ventilation from earth tubes for warmth in winter and coolth in summer
Use of geothermal energy
Use of new emerging technologies such as sun tubes, monitoring devices and electrical offsetting devices
von Bradsky added, “Clearly a challenge ahead will be how architects can incorporate the requirements to design homes and keep them affordable. Homes do not need to look radically different, however, there is opportunity to develop an aesthetic based on the functional needs of zero carbon housing. Long term flexibility, through adaptable and extendable plans, fascinates us as architects but we also face challenges such as summer overheating and adequate space for recycling bins and cycle storage.”
We set a target for a part of a typical greenfield urban extension to achieve Code Level 6* and the site and brief was modelled on the requirements of English Partnership’s Carbon Challenge competition for a carbon neutral development on a series of sites nationwide. The site was a modest 30-40 unit scheme, part of a wider masterplan for Kings Reach, Biggleswade, set to a density not exceeding 40-50 dwellings per hectare.
Paul Willis, Head of Construction, at Places for People, and David Taylor of Alan Baxter & Associates, supported PRP directors in the judging of entries.
Paul Willis, said, “The whole of the construction industry is grappling with the challenge of building low or zero carbon developments. I was particularly impressed with the very high levels of enthusiasm and energy that PRP displayed by organising internal design competitions to address such a key issue. I hope that the approach, quality and standards demonstrated by PRP’s architectural teams are reflected in other practices in the industry, in which case organisations like Places for People, who aim to create sustainable developments where people choose to live, should be truly encouraged.”
The Carbon Challenge booklet, featuring all eight design concepts, can be downloaded from the Knowledge section of our website under publications www.prparchitects.co.uk/knowledge/research/CarbonChallenge2007, or to obtain a copy of the design booklet, please contact Vanessa Clarke (vanessa.clarke@prparchitects.co.uk).