Although the drivers for adaptive reuse are often financial, working to maximise existing built assets for our clients can offer many sustainability opportunities and benefits, particularly in dense urban locations. 

Aside from the obvious carbon savings of avoiding new build, the principles of adaptive re-use can be extended beyond the client’s project ambitions, to address the construction process itself and the way in which the inevitable removal of building fabric is addressed. 

South Molton, by Grosvenor and Mitsui Fudosan UK JV, is a complex, mixed-use redevelopment in Mayfair, developed around a rich variety of existing buildings. It includes the retention of 21 listed buildings and façades which make a significant contribution to the conservation area. Hopkins Architects has been engaged with this exemplary project since 2018 and has developed planning and circularity strategies based on the principles of ‘adaptive reuse’. 

Two buildings, Brookfield House and 56 Davies Street, had Certificates of Immunity and are being removed to facilitate the development of two new office buildings. Both buildings had been constructed with Portland Stone facades and are still in good condition, so we developed proposals to carefully dismantle the facades and reuse the existing stone.  

In order to reuse as much stone as possible, the new facades have been developed as facsimiles of the originals. But in order to achieve modern commercial floor-to-ceiling heights, we needed to extend and stretch the facades vertically. This meant mixing existing stone cornices and window surrounds with ‘adapted’ stone cut to new sizes, and entirely new stone. At 200mm+, the existing stone was wide enough to be sliced in half, effectively doubling the quantities we had to work with, and significantly reducing the requirement for new material. 

Across both buildings, 4,750 blocks or 550 tonnes of Portland Stone was adapted and incorporated into the new scheme, equating to 180% reuse of the original stone.  This materials-led approach to adaptive re-use was deployed project-wide to include other major elements, including -  

Bricks: Over 55,000 bricks were saved from demolished buildings for re-use. We proposed these on one of the pre-cast panel facades, but due to issues with warranties, used them instead for walls dividing retail and restaurant units at ground floor. 

Ground floor doors: We retained the original doors to the retained facades even though they were two steps above pavement level, adapting them to achieve a level threshold, with new additional lower panels. These not only saved carbon but also helped preserve the original built heritage. 

Ceiling tiles, carpet tiles and light fitting: These were all saved from the original building, and are being reused within the new fitout. 

Other embodied carbon reduction strategies have been incorporated across the scheme. This includes adopting recycled steel which has reduced virgin steel requirements by over 200 tonnes, pre-fabricating façades, and conducting a forensic analysis of the embodied carbon of the fitout to specify the most appropriate and sustainable materials with the lowest impact.  

Materials re-use has an increasing role to play in our circular economies, but more collaborative work is required to look at obstacles like warranty requirement. Circular Do Tank, a cross-industry organisation, has recently been set up to look at issues such as warranties, logistics and storage, financial incentives and carbon credits with the aim of setting standards to adopt best practice.