The Riba Stirling Prize for flamboyant new architecture faces a humble challenger – the Reinvention award for the transformation of second-hand buildings. The Royal Institute of British Architects has created the new prize to encourage architects to pour their creativity into refurbishing existing buildings, rather than demolishing them in favour of new-build.
If developers replace an existing building with a new one, vast amounts of CO2 are created to make the bricks, cement and steel for the replacement. If instead they can reshape the interior of the existing building while keeping the shell intact, emissions are greatly reduced.
The shortlist for the Reinvention prize is: Holborn Community Association in London, where a cramped inner London site was transformed; Houlton School in Rugby, a former historic radio station turned secondary school; Museum of the Home in London, a repurposing of a building previously scheduled for demolition; and University of Wolverhampton School of Architecture and Built Environment where old buildings were revitalised to form part of a modern campus.
The award is recognition of a new trend. So far, architects have mainly focused on operational carbon – the pollution caused from heating and powering a building. Knocking down a building with poor insulation and replacing it with a more energy-efficient newbuild property may seem an obvious improvement. But the new-build causes large amounts of carbon embodied in the fabric, thereby undermining the green credentials of the replacement.
This is especially true if architects achieve high values of heat and energy conservation in the new-build by using materials with high embodied carbon – such as steel and cement. The ideal project, according to Riba’s new thinking, is to take an old, leaky building and improve its operational performance by using low-carbon materials such as timber, which actually locks up carbon for the future as the trees grow. Experts have now produced a pyramid of carbon intensiveness for materials, with aluminium at the top and natural materials such as wood at the bottom.
The new prize was championed by outgoing Riba president, Simon Allford, who said: “We have a collective responsibility as architects to minimise our impact on the planet’s resources and maximise the societal and economic benefits of our work. The inventive reuse of buildings is critical to reducing carbon emissions and, whilst often not the simplest solution, requires exceptional creativity and vision – I look forward to seeing some inspiring examples in due course.”
The UK government is lagging on obliging firms to calculate embodied carbon. Holland imposed a duty on developers to declare it in their building data in 2013. France followed in 2021. The UK is considering including it in building regulations for 2025.
Marion Baeli from architects Studio PDP said the profession was struggling to adjust to the latest thinking on energy in buildings.
She said: “People have leapfrogged from the old situation of not taking any notice of energy related to buildings. Now they have become so carbon-literate and missionary about the operational emissions of a building that they are not focused on the really important aspect – the material.
“And there’s another problem. Some architects aren’t worrying too much about energy use in buildings because the grid will soon be zero-carbon, so the architects can wash their hands of the problem.
“That just isn’t right. We need to be making sure that the energy use over the life of the building needs to be best possible. Buildings will be emitting for decades – and we need to take pressure off the grid which will be used for factories and cars and heating.”
Roger Harrabin is former BBC Environment Analyst and was a judge on the Reinvention award. His film The Art of Cutting Carbon is on BBC iplayer
