Retrofit First, Not Retrofit Only

London’s commitment to sustainability is commendable. With the built environment contributing significantly to carbon emissions, the principle of “retrofit first” is a logical and necessary planning strategy. However, some London boroughs are misinterpreting this principle, treating it as “retrofit only” and rigidly opposing redevelopment, even when retrofitting is unviable or counterproductive. This approach risks stifling progress, undermining housing delivery, and even increasing long-term carbon footprints.

The core idea behind “retrofit first” is simple: where a building can be adapted and upgraded to meet modern environmental standards and the site optimised, that should be the preferred route. Retrofitting existing structures reduces embodied carbon and preserves architectural heritage, making it an essential tool in the fight against climate change. However, it was never intended as an absolute rule. When councils refuse to consider redevelopment in cases where retrofit is impractical or delivers suboptimal outcomes, they turn a sensible policy into a dogmatic straitjacket.

Some London boroughs are now routinely blocking schemes that propose demolition and replacement, even where the new build would be more energy-efficient, better designed, and capable of delivering much-needed housing. In doing so, they contradict their own planning policies, which typically support a balanced approach. Most Local Plans and the London Plan acknowledge that retrofitting should be prioritised but not enforced where it is unworkable or where a new building would provide better environmental, social, or economic benefits.

Furthermore, a “retrofit only” stance ignores the potential for new buildings to be net carbon positive over their lifespan. Advances in low-carbon materials, energy-efficient design, and modern construction techniques mean that, in many cases, replacing an outdated building with a highly sustainable new structure results in a lower overall carbon footprint.

London’s planning authorities must apply retrofit-first policies with common sense and flexibility. Blanket opposition to redevelopment not only misinterprets policy but also stifles the delivery of high-quality, sustainable homes. A balanced approach, one that prioritises retrofit where appropriate but allows for replacement when justified, will achieve the best outcomes for both people and the planet.

Writer: Anthony Frendo, Planning Director