Cllr Henry Higgins is the founder of Blackridge Planning Insight and a councillor in Hillingdon
This summer, during a Red Extreme Heat Warning in June with temperatures forecast to reach 40°C, a homeowner in North London received a letter from their council ordering them to remove the air conditioning unit they had legally installed. The grounds: no justification had been demonstrated for mechanical cooling.
This was not an isolated case. Councils in Camden and Islington have adopted planning policies specifically designed to discourage air conditioning, on the grounds that it increases energy demand and warms the surrounding urban environment. Ministers were forced to clarify that air conditioning is not banned nationally, and that councils should take a ‘common-sense approach.’ It is a phrase that means precisely nothing when the practical effect of council policy is that homeowners are being told to open their windows during public health emergencies and call it climate resilience.
Conventional split-system air conditioning units are energy-intensive. They generate urban heat island effects by pumping hot air into streets. If powered by grid electricity from fossil fuels, they move the carbon problem rather than solving it. These are legitimate concerns. They are also entirely the wrong response to the wrong question.
The right question is not how to stop people cooling their homes. It is why Britain is still building and maintaining homes that cannot cope with the climate we already have, let alone the one that is coming.
Just over four million British homes have air conditioning, about one in seven. More than nine in ten American homes do. That gap was once explained by climate. 2025 was the hottest year Britain has ever recorded. The summer that followed was the hottest ever. The explanation has expired.
Solar generation itself kept breaking records through the summer: a new all-time peak of 15.2 gigawatts on 23 April, then June, July and August each becoming the best month for solar power Great Britain has ever recorded, with July the highest-output month in its history. NESO had already warned the system would see periods of surplus electricity, supply outstripping demand, as that solar boom met the heatwave head-on. Nearly 1.7 million British households now have solar panels on their roof, and across 26 heatwave days this summer, analysis by Utility Bidder put their collective savings on electricity bills at £86.7 million, largely from generating their own cooling for free.
A homeowner with solar panels running air conditioning during a heatwave is consuming zero net fossil fuel electricity. They are using power that would otherwise be curtailed as surplus. They are keeping themselves safe during a public health emergency. And a council planning officer is sending them a letter telling them to stop.
The councils’ argument holds for conventional grid-powered air conditioning running on fossil fuel electricity, which does increase demand and warm the surrounding environment. Solar-powered air conditioning at a time of grid surplus is a different case entirely. The planning policies being enforced were written without that distinction, and they are now causing harm.
Solar panels and air conditioning have near-perfect seasonal alignment. The sun that makes your home hot also generates the electricity to cool it. A modern air-to-air unit delivers 3 to 5 units of cooling for every unit of electricity consumed. On the hottest days of 2026, millions of British homes could have run cooling for free. Councils are banning the solution while the problem worsens.
The air conditioning row is a symptom of something much deeper. Britain has spent four decades building homes with Victorian assumptions about temperature baked into their design. We prioritised keeping heat in during long, grey winters. The result, in a warming world, is a national housing stock that functions as a solar oven in summer. The better insulated the home for winter, the worse it performs in a heatwave if summer cooling was not designed in from the start.
Only around one in seven British homes have air conditioning, even after that number doubled in just three years. Ninety percent of American homes do. The majority of homes across southern Europe do. That gap was once explained by climate. The explanation stopped working the moment 2025 became Britain’s hottest year on record, and the summer after it became the hottest summer. What remains is a design failure of historic proportions, and a planning system that responds to it by banning the cure rather than addressing the disease.
New builds fare little better. Building Regulations introduced Part O in 2022, specifically to address overheating, but it only covers new homes. It has nothing to say about the hundred thousand-plus former offices converted into flats over the past decade under permitted development rights, where conversion applications have risen 58% in three years. Research from the Town and Country Planning Association and UCL’s Bartlett School of Planning found that nearly half of residents in these deregulated conversions reported their homes overheating in summer. Even where Part O does apply, passing it only makes catastrophic overheating somewhat less likely. That is a very low bar, and it is the bar we have set.
I believe in markets, individual freedom, personal responsibility and long-term thinking over short-term political convenience. None of those principles supports what the councils are doing. And none of them supports the status quo in British housing design.
The planning system is currently obstructing homeowners who want to do the right thing. External shutters and shading systems, which outperform internal blinds considerably at keeping homes cool, require planning permission in conservation areas. Ground source heat pumps, which provide near-zero-cost passive cooling in summer, require boreholes that trigger permitted development restrictions. MVHR ventilation systems, which eliminate the need for mechanical cooling in well-designed homes, require roof penetrations that planning officers in some areas have challenged. The system is actively impeding the market solution it should be enabling.
The answer lies in removing the barriers to better alternatives, rather than banning air conditioning outright. External shading, solar panels, MVHR penetrations, heat pump installations and green roofs should all be Permitted Development on all property types, including flats and conservation area properties where the installation is not visible from a public highway. The right to make your own home more comfortable and more energy-efficient should not require a planning officer’s permission.
Simultaneously, council policies that prohibit or discourage air conditioning as a matter of planning ideology should be abolished. Councils may set aesthetic standards for external equipment. They may not prohibit cooling on grounds of principle. A homeowner with solar panels, making an informed choice to install efficient air-to-air cooling powered by their own roof, is the market working exactly as it should.
Existing homeowners should not need a planning officer’s permission to make their home safe during a heatwave. This is the state obstructing individual choice at the expense of public health, dressed up as protection of the built environment.
Beyond deregulation, there is a positive case to make. Britain needs a single, unified Home Climate Standard: a performance-based requirement that every new home must maintain indoor temperatures between 18°C and 26°C in 99% of hours across a modelled typical year. It fixes the outcome and leaves the method to the market. Builders could reach it through Passive House fabric, solar design, MVHR, external shading, ground source heat, green roofs, or any combination of them.
This is genuinely conservative. It sets a clear market requirement and trusts the construction industry to find the most efficient way to meet it. It also creates legal accountability for builders who deliver homes that cannot maintain comfortable temperatures in the climate their customers actually live in. No amount of regulatory guidance has ever been as powerful an incentive as liability.
The current patchwork of Part L, Part F and Part O regulations was written in a different era for a different climate. It treats winter warmth as the design objective and summer cooling as an afterthought, and it treats the whole of England as a single climate zone. The rules set out a process to follow rather than an outcome to hit. This patchwork needs replacing in full.
We already know what a home comfortable in both winter and summer looks like, how to build it, how to power it, and what makes it affordable. What we lack is the regulatory ambition to demand it, and the courage to remove the planning obstacles stopping the market from delivering it.
Telling a homeowner to open their window during Britain’s hottest summer on record shows a planning system that has lost contact with the people it is supposed to serve. Conservative policy should be better than that, and so should the homes we build next. The planning system that governs both should stop making Britain hotter and start helping it get cooler.