Sustainability adviser to the RIBA Stirling Prize jury, Simon Sturgis, gives his verdict on the six buildings in the running for this year’s award. Photography by Jim Stephenson
This year’s Stirling shortlist is, across the board, notably more sustainable than in previous years. In the past, most projects complied with existing UK sustainability standards with little ‘extra over’ innovation. This year most of the buildings are stretching beyond best practice, some to an impressive degree
Acting as sustainability adviser to the Stirling jury for the second year in a row has enabled me to examine in detail the effectiveness of the new RIBA Awards sustainability statement put in place this year. The revised statement expands the criteria beyond a focus on energy use to cover a broad range of issues of particular relevance to architects. These include the environmental cost of materials used to construct a building and over its lifetime, social and community impacts, ethical sourcing, future climate change and biodiversity.
Architects too often default to a services engineer to inform their sustainability strategy. Yet for new buildings, operational energy use is now a relatively minor environmental impact. The choice of materials and how they are used are what really matter. The new sustainability criteria require a more comprehensive and in-depth approach. Based on the information that this year’s Stirling shortlisted practices have submitted about their projects, this more rounded and rigorous approach raised the bar on sustainability in the RIBA Awards process.
Bushey Cemetery is the most perfectly sustainable building in that it is designed for complete removal in 60-70 years
My views on each project are listed in the order the jury visited the buildings. I should stress that my views should not be seen as any sort of hint as to what the jury has yet to decide! As last year, my role is advisory.
Our first visit was to Tate St Ives. This project is a combination of a refurbished existing building by Evans & Shalev, plus Jamie Fobert’s extension. The new gallery required extensive excavation on a tight site and has resulted in an elegant, top-lit, concrete ‘box’ which provides great thermal mass thus stabilising the temperature – important for works of art.
The next project we visited was Níall McLaughlin’s impressive Sultan Nazrin Shah Centre in Oxford. This single-storey, stone-clad building employs a restricted palette of simple natural materials, suggesting low maintenance and long life. It is full of natural light and combines mechanical with natural ventilation. The services are mostly located below the ground floor which is raised to address potential flooding.
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We then travelled to Bushey Cemetery to visit the new prayer halls by Waugh Thistleton. This is, to an extent, the most perfectly sustainable building in that it is designed for complete removal in 60-70 years. The materials: rammed earth (with 2 per cent cement) walls with timber, brick, ceramic tiles and Cor-ten are low key and have great recycling potential. Because the main gathering prayer rooms are often open to the outside, they are only provided with modest underfloor heating. The building group has service loads that are minimal and optimised with heat recovery and photovoltaic panels.
Next up was Storey’s Field Community Centre and Nursery by MUMA in Eddington, North West Cambridge. This elegant brick building addresses all aspects of what a sustainable scheme should be. Its brief was developed through extensive community engagement from the outset. The building is predominantly naturally ventilated, highly flexible, and has been designed to manage future climate change. Extensive thought has been given to natural light balance. The selection of materials and associated detailing is well-designed and well-executed, suggesting durability. Another factor is the economy of the design in that many elements of the building have more than one use. This all points to an overall resource efficiency in conception, construction and use.
Bloomberg is extraordinary, and indeed a sustainability laboratory; however it is not a truly sustainable building itself
On the last day, our visits started with Chadwick Hall student accommodation by Henley Halebrown in Roehampton. The robust brick façade incorporates concrete detailing and is deeply modelled, which provides passive shading. Above-average levels of insulation, a high glass-to-wall ratio augmented by prioritising passive design measures combine to deliver a good energy performance and contribute to student wellbeing.
Our final visit was to Foster + Partners’ Bloomberg HQ in the City of London. This remarkable building is undoubtedly a long-lasting carbon investment, incorporating many innovative sustainability features. It has both natural and mechanical ventilation, the latter operating effectively as a stack effect through the internal atrium and up through the roof. Bloomberg has achieved a design-stage BREEAM Outstanding ‘highest BREEAM rating ever’. Is it, therefore, a highly sustainable building? If Fosters used to be known for ‘minimalist’ design where every component was optimised, then this has to be ‘maximalist’ in terms of the enormous resources used to create it. It is a bit like a Formula 1 car where vast resources go into maximising performance, even though petrol engines will be obsolete in a few years for the good reason that they are not sustainable. So, to answer my question, this building is extraordinary, and indeed a sustainability laboratory; however, in my view it is not a truly sustainable building itself nor is it a model to others for the future.
So which finalist best meets the 21st century’s two major environmental challenges of global warming and resource depletion? From the perspective of the overall efficiency of lifetime use of resources, and the consequent minimised environmental impact, my preference has to be Storey’s Field Community Centre and Nursery by MUMA.
Simon Sturgis is author of Targeting Zero: Embodied and Whole Life Carbon Explained, published by RIBA Publishing