Net-zero carbon refurbishment of two floors of a 1920s, neo-Georgian building in the Mayfair conservation area to meet LETI retrofit guidelines and Grosvenor’s bold environmental goals.

Net-zero carbon refurbishment of two floors of an apartment building in the Mayfair conservation area to meet LETI retrofit guidelines and Grosvenor’s bold environmental goals.
Existing office space is converted back to its original residential use while the building remained occupied. A building fabric upgrade, air source heat pumps and PV panels at roof level have improved the energy use efficiency to exceed the client brief. The design provides future proofing for further upgrades.
Constructed in 1920 in a neo-Georgian style, the building has sash windows on Davies Street and Brook’s Mews and Crittall windows to the lightwell. As well as internal wall insulation, secondary vacuum glazing was added to the sash windows and the Crittall windows replaced.
Following a clear ‘Sustainable Development Brief’ from the client, the project was identified as a pilot study that could deliver Net Zero Carbon aligning with the UKGBC’s 2019 framework. The brief set out the challenging, complex and collaborative pathway needed to successfully reduce carbon emissions in the built environment. It required the reduction of construction impacts and operational energy use, with an increase in renewable energy supply and offsetting of any remaining carbon.
Using a fabric first approach with the reuse of existing building fabric, the team was committed to finding the lowest embodied carbon solution. For example, demonstrating that no structural reinforcement additions were necessary. The project has either met or exceeded all targets and delivers a predicted CO2 improvement of 93%.
Together with improvements to the internal layout, the project provides desirable and sustainable residences in the heart of Mayfair.

“Given the high proportion of existing and heritage buildings in central London, there is significant potential for the lessons learned from this project to be applied to many more sites. Instead of waiting for an entire building to become available for an upgrade, this project demonstrates that a phased approach can be effective, helping to pave the way for a lower-carbon future.”
Luke Richardson-Brown, Partner, Studio PDP