Should you always retrofit?

That was the question grappled by architects and engineers during a webinar this week put together by Max Fordham and Partners and aimed at helping to hit the UK’s critical net zero targets.

Principal engineer at the firm Andrew Leiper said that for building designers there was an urgent need to address man-made global warming and climate change and the impacts we are having on a natural world in the ‘midst of a great extinction event’. 

‘We need to get a lot smarter about where we source our materials and how we reuse materials that we’ve already gathered’, said Leiper, especially since in the UK construction of the built environment contributes around 40% of total carbon emissions. There has been a massive increase in attention paid to the climate emergency through the work of organisations like Architects Declare, and key industry guidance from LETI and others, with national policy catching up and individual corporate policy ‘leading the way’ with pledges to be carbon natural by 2030. ‘Energy and resource efficiency are vitally important, along with carbon emissions, if we are to achieve our aims to decarbonise’. But as with the firm’s work at Croft Gardens in Cambridge, retrofit is not always the answer, especially when existing buildings are in poor structural conditions and the space they offer is small and low-rise, with a need for increased accommodation provision on the same site.

FCB Studios’ Peter Clegg said there were many typologies where we need to retrofit, with domestic buildings probably being the most advantageous. But he also presented the case for three 1960s Brutalist non-domestic buildings, including the Southbank Centre, where he said the practice was the only one on the competition shortlist pushing the case for retrofit. ‘We were the only people that said: ‘maybe you should hang on to these buildings because maybe they have intrinsic value’, said Clegg. They represent not only an era, but also 22000 tonnes worth of embodied carbon, and a ‘concrete block of a building’ that is urban typography that needed dealing with through renovation and improvement of its interiors and raising its environmental quality, as well as increasing the density of the site. 

The practice’s scheme improved ventilation and lighting, while also retaining the project’s model way of treating plant and ‘guts’ on the outside. ‘This building was actually a precursor to the Pompidou Centre’, he said. Clegg also showed other examples of retrofitting work including the 1969 Bristol University Students Union by Alec French and Wiggins Teape Building (Mountbatten House) in Basingstoke by Arup Associates in 1976. 

The big carbon wins often come from replacing HVAC and lighting; there are often potential area savings to be made by reusing plant area, increasing site capacity without demolition can add value without carbon costs, decanting and phasing is a big issue and there are obviously huge, embodied carbon savings in retaining foundations and structure. ‘But we need to learn to love our Brutalist legacy and work with it and improve it’, added Clegg.

Other speakers at the event included Dr Joe Jack Williams, also of FCB Studios, showing case studies such as the savings made from a refurbishment project at Senate House in the University of Bristol, while Kiru Balson of Max Fordham spoke about the impact issues of health and wellbeing for users of buildings and how they can be optimised.

Download Max Fordham's Net Zero Carbon Guide.