Westminster City Council has unveiled its City Plan Partial Review, introducing new policies to tackle climate change, boost affordable housing, and guide future development across the city. The updated plan comes after three years of consultation with residents, businesses, developers, and local stakeholders.
At the heart of the review is the council’s new Retrofit First policy, which requires developers to explore all reasonable options for retrofitting and adapting existing buildings before considering demolition. While not every building can be retrofitted, the policy prioritises refurbishment over redevelopment wherever feasible, placing Westminster among local authorities leading on climate action.
The urgency of the approach is evident: Westminster’s built environment accounts for 90% of its total CO₂ emissions, compared with roughly 40% for a typical council area. In the first half of 2025, the council’s Sustainability Team monitored 19 planning schemes, covering over 143,000 sqm of office, hotel, and retail space. Working closely with developers, the council achieved a 24% reduction in construction-related carbon emissions compared with average emissions recorded when the policy launched in 2023. This represents a saving of 27,500 tonnes of CO₂, equivalent to the annual energy use of almost 3,700 homes.
The City Plan Partial Review also strengthens requirements for affordable housing. The split in new developments will now shift to 70% social rent and 30% intermediate homes, up from 40% and 60% respectively. For the first time, even sites with fewer than 10 homes will be expected to contribute to affordable housing delivery.
Four new strategic sites have also been identified for mixed-use development: St Mary’s Hospital, Westbourne Park Bus Garage, land adjacent to Royal Oak, and Grosvenor Sidings. These allocations provide clarity for developers and landowners, supporting the creation of new homes, modern workspaces, improved public spaces, and a new state-of-the-art St Mary’s Hospital.
Councillor Geoff Barraclough, Cabinet Member for Planning and Economic Development, said:
“The City Plan Partial Review focuses our efforts on the most important challenges facing Westminster: tackling the climate crisis and delivering more genuinely affordable homes.
“Our Retrofit First policy sets a new benchmark for local authorities. It will help reduce carbon emissions from today’s buildings and has the potential to be the biggest single emissions-reduction initiative undertaken by any council in the country.
“We are also strengthening our commitment to affordable housing by increasing the proportion of social rent homes in new developments and ensuring smaller sites also play their part.
“Taken together, these policies create a roadmap to a fairer, healthier and more welcoming Westminster – one that works for today’s residents and for generations to come.”
