Developers, architects, agents and planning authorities are getting the climate message about the need to prioritise working with existing built fabric, rather than demolition and rebuild. But continued education is needed about the use of new technology, and there should be a concentration on flexible, adaptable buildings to cope with a rise in wellbeing issues for users in the light of the COVID-19 pandemic.

Those were some of the key thoughts and messages to emerge from an NLA think tank this week: ‘Adaptive reuse of historic buildings: meeting the climate agenda and protecting our heritage’.

Think Tank chair and EPR director Mark Bruce said that with changes in perceptions over retrofit across most media and changes in regulations, we are ‘moving in the right direction’, and representatives of local authorities agreed that there had been sizeable shifts in approaches out in the field.

Southwark senior design and conservation officer Tracy Chapman said the council was seeing more cases of locals objecting to the losses of particularly industrial buildings in areas like Bermondsey, Peckham and the Old Kent Road, with people getting ‘upset’ about what they see as a loss of ‘character’ and developers seeking to replace them with office blocks or hotel buildings that ‘could be from anywhere’. People are asking why such heritage buildings cannot be retained even if in part, she said, and developers are also finally getting that message too. 

In Westminster, said John Wilman, Area Design and Conservation Officer, City of Westminster, it is a mixture, but there is a trend towards considering retention of more modern 1930-1950s buildings which have character but which in previous times would have been demolished more readily. ‘I think there's definitely more people that are thinking of this more’, he said, ‘and it's due to the architects going: hey, guys, you know you could save a lot of money and reduce carbon and win some plaudits with your neighbours if you just think about keeping the building’. 

But flexibility holds the key for those considering adapting historic buildings to cope with issues arising from the pandemic. Louise Wille, Principal Sustainability Consultant, Hoare Lea, said we need to build in flexibility in layouts, principally because we do not yet know how people want to live and work in the future, building in extra capacity in mechanical and electrical systems or to easily move it with raised access floors. ‘I think flexibility is key to enable these things that we don’t know that might happen, to happen’, she said. Grosvenor Estates director of sustainability programme Victoria Herring said people are concerned about the future and flexibility is an important part of that but there had definitely been a shift to wellbeing and the end user. If that agenda could be linked to retrofit, that would be a good thing, she added. And Jude Harris, director of Jestico+Whiles agreed that adaptability was key. ‘I think we’ve got to be not afraid to adapt historic buildings’, he said, echoing Wilman’s earlier point that for several hundred years we have been adapting buildings to cope with things like electricity, gas, heating and the internet. ‘I think this is just another chapter in the rich history of the buildings we are working with’.

Wille suggested that the climate emergency had led to a greater drive to report a lot more on embodied carbon, inherently present in existing buildings, something which makes a big difference to the overall assessment compared to new build. Bruce, meanwhile, said that in EPR’s refurbishment work on The Ned and the challenge of upgrading the original Grade I listed building to minimise the loss of energy, windows were a particular challenge and one which is presenting issues on other projects too. Valentina Galmozzi, design director at AKTII talked about her work at the Museum of London with Stanton Williams and the challenging job of finding a balance between upgrading and retaining the scheme’s features, such as its timber arches, but that on existing fabric historical buildings tend to be ‘overdesigned’ with thicker walls, for example, than in modern construction. Thus they often behave better than modern buildings on energy model terms. 

Tibbalds director Jane Dann added that at a masterplanning level or on large sites, locally listed buildings are often assessed in terms of retaining existing fabric only for new teams to come in and make the case for demolition and rebuild on the grounds that buildings cannot be used effectively. ‘I think there’s quite a lot of tension around that’, she said. But there has ‘definitely’ been an increase in the numbers of applications made for replacement windows and double glazing on listed buildings said Chapman, without even considering retention or other methods of sorting out draught issues. ‘And it’s wholesale replacement: we’re seeing more and more of that’, she said. ‘Definitely a big increase in the last couple of years’.

Knowledge and education are important here, said Bruce, pointing to the firm’s Old War Office scheme and engagement with specialists to investigate improving its large windows. Ruth Oates, project director at Buro Four, agreed, adding that an educated client that understands the value a team can bring to redevelop schemes is also important, as exemplified in its work on the Museum of London’s Grade II listed Dome roof on the Poultry Market. 

Robbie Kerr, director of Adam Architecture said that he was working with one of its enlightened clients and consultants on trying to develop more sustainable, better U-valued sash window boxes but there are still some aesthetic hurdles to get over on some of the technology being used, even if it is indeed ‘moving in the right direction’. Wilman added that looking at the whole building rather than picking just one aspect was advisable – ‘Don’t just look at double-glazing as a panacea’. PDP London conservation architect Jokin Asiain pointed to new products like vacuum glazing from companies like Fineo by AGC, even if, said Herring, some are expensive and difficult to scale up across estates. 

In the last decade, said Bruce, clients have also become more aware of the potential for retrofit in more modern buildings where once there was no question about retaining the building. ‘I think that’s a huge amount to do with the power of planning’, he said. ‘It’s a really interesting moment in time where clients realise that it’s not even a choice now. It’s not just about can we build new buildings, but it is how can we deal with existing buildings? That’s hugely positive for energy and the environment’.