The Ministry of Housing objects:

Air conditioning can be installed in both existing and new homes.

And yet, I have never experienced a home in the UK that has air conditioning.

What I’ll look at: air conditioning in rented flats in London

I’ll focus on rented flats in London since that’s what I’m most familiar with. This study also shows that Londoners are most likely to report overheating at home.

Do Londoners not want air conditioning?

Maybe flats don’t have air conditioning because people don’t feel the need for it?

Surprisingly, one of the authors of the study above claims that 30 per cent of Londoners use air conditioning at home.

It was not surprising, said Dr Khosravi, that Londoners were found to be the most likely to have air con in their homes (30 per cent), “because air con use is about affordability.”

This is much higher than I expected. But I suspect it doesn’t mean that 30% of flats have installed proper air conditioning.

Instead, it’s likely to be janky portable air con setups, like my one in the photo below. I also found an old photo from March 2022 where it was 32 degrees inside.

I want air conditioning, and clearly many people living in London feel the same.

Is affordability the reason homes don’t have AC?

The quote above suggests cost as a big factor. I’m skeptical for a few reasons:

1. The survey asks about the most important consideration when buying AC, not about why don’t people buy AC. Though maybe the data comes from a different survey?

2. Only 20% of respondents with an income over £70,000 report home AC use, compared to 15% with an income below £10,000.

3. If I search on Rightmove, I don’t think I can just spend a lot of money to get a flat with AC? They seem extremely rare, unless you’re looking to buy a £10M apartment.

Property ownership does make AC use easier, but I don’t think cost is the reason for low rates of AC installation.

Even if cost was a concern, a substantial number of people could afford air conditioning. In 2020, 16% of London households had an income over £100,000.

Are developers building new blocks of flats with AC installed?

Overheating is a big problem in London and people are willing to pay to address it. If air conditioning isn’t banned, do new developments finally have AC installed?

I had Claude look through planning documents across 4 London councils. It didn’t find a single new build that has air conditioning.

Why do developers not build homes with AC?

It comes down to planning rules and building regulations.

Planning permission: the cooling hierarchy

The 2011 London plan introduced the cooling hierarchy. Air conditioning is only allowed as a last resort.

The increased use of air conditioning systems is not desirable as these have significant energy requirements and, under conventional operation, expel hot air, thereby adding to the urban heat island effect.

_{Image source: the overheating report for the Pudding Mill Lane development.}

Building regulations: Part O

In 2021, the housing ministry introduced Part O of the UK building regulations. It introduces requirements for new residential buildings to mitigate overheating, which came into effect in June 2022.

Part O also prohibits air conditioning unless the developer can show that there is no other way to prevent overheating.

The building should be constructed to meet requirement O1 using passive means as far as reasonably practicable.

It should be demonstrated to the building control body that all practicable passive means of limiting unwanted solar gains and removing excess heat have been used first before adopting mechanical cooling.

Additional reasons AC isn’t allowed

On top of environmental concerns, councils also deny permission to install air conditioning for noise and conservation reasons.

For example, there’s this refusal from Newham Council:

The proposed development fails to respect the character and appearance of the area and lacks application clarity on the impact of the noise produced on the living conditions of neighbouring properties

Conclusion

While residential air conditioning is not banned outright, in practice it is not permitted for new residential developments.

This encourages overheating, inefficient portable air conditioning units, or water-cooled air conditioners that have no external unit but use a lot of water.

Retrofit of AC is possible in theory as Part O doesn’t apply to existing properties. However, this runs into problems with noise and design concerns that could have been avoided with upfront planning.

Caveats

Maybe AC-cooled blocks of flats are being built, but I wasn’t able to find them? I would like to learn that this is the case.

Maybe air conditioning really isn’t needed in new buildings that comply with Part O? Maybe Part O would work but isn’t sufficiently enforced?

I also don’t have a good understanding of UK planning rules and maybe there are loopholes that would allow AC.