Design Solution · Sustainability
Design Solution · Dream about it
Keeping 80%+ of a listed frame while extending it.
Over 80% of the listed building's structure is retained and extended by around 11,000 sqm, avoiding the carbon of demolition and rebuild. Retaining the frame while adding lettable area makes a heritage office viable for modern use. It is a low-carbon model for upgrading post-war commercial stock.
Retaining over 80% of a listed building's original structure while adding roughly 11,000 sqm of new floor area is a significant commitment to embodied carbon avoidance — the carbon not emitted by demolishing and rebuilding a listed frame is substantial, and the economic logic of extending rather than replacing an asset with inherent planning protection is equally clear. The approach is well-established in heritage refurbishment practice, but evidence_state here is claimed, meaning the specific carbon figures and the structural retention percentage are design-stage assertions rather than verified post-completion numbers. The value for a senior specifier is the model itself: an approach that turns a listed building from a constraint into a generator of net-new lettable area without triggering the consenting risk that demolition would bring. The structural challenge to understand before pursuing this is that 80%+ retention and an 11,000 sqm extension on a listed postwar frame will require detailed survey, condition assessment and specialist structural engineering well ahead of planning; the heritage consent risk does not disappear, it concentrates at the extension interface. Successful execution depends on demonstrating that new work is genuinely sympathetic rather than merely adjacent.
#retrofit #structural retention #embodied carbon