The Mayor of London may be leaning towards removing guidance in the new London Plan that effectively blocks air conditioning from being installed in newbuild homes, after declining to rule out a change.
While City Hall insists there’s no ban on AC in London homes, the guidance for developers – instructing them to prioritise “passive” cooling measures such as shading – means they are less likely to include AC in building plans as it could make it easier for councils to refuse applications.
However, City Hall has faced calls to reform such guidance, especially with the new London Plan due out next month, amid continually soaring temperatures in the capital.
Speaking at the launch of Heat Ready London yesterday (Thursday 25 June), a new city-wide plan to adapt to increasingly frequent and severe heatwaves, on what could be the hottest day of 2026 so far, the Mayor of London gave perhaps his strongest hint yet that a change is on the cards.
Admitting that developers have to use “every tool” to ensure buildings are fit for the future, he told the LDRS: “Developers can install, and they’re encouraged to install, air conditioning in homes and schools, in offices and so forth, as well as other additional measures as well such as bigger windows.
“[We also] think about heat pumps that provide heat in the winter and coolness in the summer, trees that provide shading, water fountains outside. We’re thinking about how buildings are designed.
“We’ve got to use every tool in the toolkit to make sure our buildings are [not only] fit for today, but tomorrow as well. What I can’t do is pre-judge the New London Plan for obvious reasons [by saying whether or not the guidance will change].”
Deputy Mayor Mete Coban added: “What we think is really important is at the design of any infrastructure, whether it’s homes, whether it’s a transport system, whatever, is that we can create the right level of shading in homes. But if obviously you need air conditioning to keep cool – we’re not against that.
“What we do want [to do with] this is make sure our homes are designed properly so that they’re actually cooler in hot temperatures like this, but also warmer when it’s really cold as well.
“So you’re not having to fork out lots of money on your energy because you have to power your air conditioning, but of course, if you need to use it, you can, as well as using any of the Cool Spaces we have around the city.”
Coban added that London “has been a blueprint” for other cities with the existing London Plan, in terms of its environmental measures, reducing our dependence on fossil fuels and finding ways to ensure homes are the right temperature.
The current regulations say the use of air conditioning is not “desirable as these have significant energy requirements and, under conventional operation, expel hot air, thereby adding to the urban heat island effect”. If such systems are “unavoidable”, developers must design them in order to “reuse” any waste heat produced.
Similarly, the London Climate Resilience Review recommends that “mechanical ventilation is prioritised over air conditioning”.
Earlier this year, however, the London Assembly planning and regeneration committee was told that active and passive cooling measures should work together, rather than in a hierarchy.
For now, however, City Hall officials say they are focusing on preparing the capital for rocketing temperatures. Measures in the Heat Ready Plan unveiled yesterday include retrofitting high-risk homes, increasing urban greening and expanding access to Cool Spaces – places highlighted on a map where you can go to cool down – across London.
However, Sir Sadiq admitted the measures will require significant investment, and suggested he may look to the Government for the funding needed to properly carry it out.
He added: “We know the consequences of the heatwave. There are a million homes in the areas where they suffer extreme heat. There are 1,600 schools that suffer extreme heat, along with 250 hospitals and 350 care homes – so action is required. Some of the resources can come from current pledges but there may be the need for additional expenditure.”
The department for energy security and net zero declined to comment.
Green party leader and Assembly Member Zack Polanski told the LDRS: “I welcome the Mayor publishing a heat plan, which is a step above the Government’s dangerously complacent ‘wing-it’ approach to planning for extreme weather. But the Mayor’s plan doesn’t go far enough.
“This plan lacks the funding, timelines and urgency needed to meet the scale of the challenge. We cannot afford to wait years for long-term solutions while people suffer through increasingly dangerous heatwaves.
“We need an emergency effort now to help households, businesses, schools, care homes and hospitals stay safe, with practical measures that can be put in place immediately.”
