Studio PDP Wins AJ Retrofit Award for Net-Zero Claridge House Transformation
Studio PDP has won the Decarbonisation and Net Zero category at the AJ Retrofit & Reuse Awards 2025 for its transformation of two upper floors at Claridge House, a 1920s neo-Georgian building in the heart of Mayfair.
The judges described the scheme as a “best-practice retrofit”, with one commenting: “The architect has done it all — and done it well.” Another praised its replicability, calling it a “surgical” approach that “could be applied multiple times in somewhere like Mayfair.”
“A masterclass in how a heritage building can be protected and future-proofed while occupied.”
The project involved converting existing office space back into residential use, all while the building remained occupied. Key interventions included:
Building fabric upgrades and internal wall insulation
Secondary glazing to retained sash windows
Replacement of rear Crittall windows
Installation of air source heat pumps and rooftop PV panels
Together, these measures improved energy efficiency beyond the client brief, dramatically reduced carbon emissions, and delivered high-quality homes in a sensitive conservation area.
“Claridge House shows how meaningful change can be delivered through phased retrofit - even in occupation,” said Luke Richardson-Brown, Partner at Studio PDP. “By working carefully with the building’s fabric, we achieved an estimated 93% reduction in carbon emissions - proving that deep decarbonisation is possible.”
As well as targeting energy performance, the design team ensured the building is future-proofed for further upgrades and fully compliant with emerging building safety regulations for higher-risk buildings.
Claridge House now sets a benchmark for elegant, low-carbon retrofit in heritage settings — and shows what’s possible when clients and architects share long-term ambition.
The team with the other winners of the evening
Exterior view and thermal camera