An online seminar hosted by Schüco ​and Architecture Today explored new thinking on adaptation and renovation within the built environment.

Architectural approaches to adapting and reusing buildings have changed significantly in recent years. As the awareness of embodied energy has grown, so too has the sense that architects are obliged to reuse buildings wherever possible – often requiring levels of skill and imagination at least equal to those involved in new builds. Likewise, high-profile projects, such as Herzog & de Meuron’s creation of Tate Modern from London’s Bankside power station, or David Chipperfield’s renovation of the Neues Museum in Berlin, have eloquently demonstrated that work to existing buildings can influence architecture beyond the practice of renovation and repair.

In this context, architects are developing new specialisms and establishing positions in relation to reuse, ranging from commitments only to work on existing buildings – or never to demolish them – to efforts to develop new markets in reclaimed materials. An online seminar hosted by Schueco UK explored current thinking, hopes and concerns regarding our handling of the existing building stock. Chaired by Architecture Today editor Chris Foges, the panel comprised Rob Leechmere, associate architect at Jonathan Tuckey Design; Sarah Castle, founding director of IF_DO; and Stephen Bates, founding partner of Sergison Bates architects.

Rob Leechmere’s presentation focused on four key themes that Jonathan Tuckey Design employs when transforming or repurposing existing buildings. Explored through four diverse projects, ranging from a grade-two listed house in London’s Marylebone to a former military observation post in Andermatt, Switzerland, the first of these themes, ‘richness through dialogue’, concerns the overlaying of competing or harmonious ideas to create a more layered, nuanced approach. The second, ‘context and condition as direction’, asks questions about the importance and relevance of site influences; or as the architect put it, ‘should what is found on a particular site affect what is latter built on said site?’

A completed building is rarely perfect or unalterable – rather it is in the words of Michael Graves, ‘an unfinished fragment of a larger edifice’, and as such liable to change and reuse’”

The third theme, ‘embracing imperfection’, considers the importance of ‘welcoming’ the irregular and broken features that inevitably form part of existing structures. Using the example of a refurbished 400 year-old Cornish longhouse, Leechmere professed that ‘designing to incorporate a building’s history makes for a much more enjoyable and rewarding process’. Central to the longhouse project are crafted joinery items and ceilings that are carefully scribed around the dwelling’s lumpen walls, acknowledging both the past and present. Exploring the last theme, ‘unfinishedness’, Leechmere urged architects to accept the idea that a completed building is rarely perfect or unalterable – rather it is in the words of Michael Graves, ‘an unfinished fragment of a larger edifice’, and as such liable to change and reuse.

Sarah Castle underlined the importance of retrofit in view of the fact that around 85 per cent of the UK’s current buildings will still be in existence by 2050. Using IF_DO’s redevelopment of the derelict Observer building in Hastings as a case study, the architect explored the benefits of a retrofit approach that closely involves the local community and is a catalyst for positive social change. Currently on site, the mixed-use project forms part of a larger ‘civic ecosystem’, and will house work, leisure, residential and community spaces.

“The Observer scheme explores the idea of retrofitting as a process for active inclusion, or what our client calls ‘darning the fabric’”, explained Castle. For both architect and client, the benefits of retrofit extend far beyond the construction and occupation phases to the ways in which the building can be used while the design is still being developed. So far, this has included community involvement with design workshops, building tours, art exhibitions and even practical lessons on joinery and stud wall construction for local residents.

Castle also spoke about the importance of sustainability in terms of retrofit. On the Observer building the environmental concept is simple and comprehensive: ‘be lean (use less energy), be clean (supply energy efficiently) and be green (use renewable energy sources)’. In practical terms this will include photovoltaics, air source heat pumps, high levels of insulation, energy-efficient windows, a lightweight, prefabricated rooftop extension, and repurposing part of the existing steel substructure as pergolas for roof terraces and gardens. Inside, the architect will be limiting interventions to ‘just what is required’ to minimise the use of new building materials. Overall, the project is expected to reduce carbon emissions by 149 tonnes per year.

It is imperative that we demolish as little as possible and make use of – what we would call in a circular economy – the ‘material bank’ that a building holds“

Stephen Bates’ presentation explored the ongoing transformation of a 1930s Citroen car factory in Brussels into a major modern art museum. Won in competition by Sergison Bates, Kanal Centre Pompidou challenges traditional approaches to working with existing buildings – not least the Venice Charter (1964), which seeks to clearly delineate between old and new elements. The project is conceived as continuous narrative, where each historical ‘layer’ is treated equally and without judgement. “Our attitude to re-use at Kanal is something we call ‘radical optimism’”, explained Bates. “We trust in what is already there, and try to touch the building as lightly as possible.” The adoption of a ‘soft interface’ between old and new is also driven by strong environmental concerns.

Bates spoke eloquently about the building’s lightweight filigree steel structure, and how patina is one of the most vulnerable historical layers when it comes to re-use. Competing needs to retain the existing building fabric while ensuring state-of-the-art environmental servicing – commensurate with showcasing international art – has led to the insertion of three new structures, which are themselves reusable. For the architect, re-use projects, such as Kanal, have to contain an emotional charge, that is able to co-exist with more pragmatic issues, such as technical performance and adherence to building codes.

Bates provided a fitting conclusion to his presentation that provided further food for thought: “It is imperative that we demolish as little as possible and make use of – what we would call in a circular economy – the ‘material bank’ that a building holds. Even if we don’t re-use something within the building it should be possible to repurpose it somewhere else. In turn, new elements that are introduced should themselves be demountable and reusable. The construction industry in general has this idea of removing as quickly as possible in order to create a tabula rasa where something new can be made. This has to change.”