However, the London borough of Camden has taken a particularly strict stance on AC, even for retrofits. Home owners need to show that they really need air conditioning and that alternative cooling methods can’t solve the problem.

In this article I’ll take a closer look at AC planning rules in Camden.

Adapting to climate change: CC1 and CC2 of the 2017 Camden Local Plan

The 2017 Camden Local Plan outlines the council’s development vision and sets out the policies that guide planning decisions in the borough.

Beyond the usual rules on noise and local character, the document contains two policies in the “Sustainability and climate change” chapter that impact air conditioning installations:

• CC1 Climate change mitigation: buildings should reduce carbon dioxide emissions

• CC2 Adapting to climate change: encourages measures like green spaces and sustainable construction

When does Camden permit air conditioning?

To get planning permission for air conditioning units, Camden residents need to show that:

1. They’ve explored other steps on the cooling hierarchy (like increasing shade or ventilation)

2. Dynamic thermal modelling shows that their home is still too hot

CC2 of the Camden Local Plan explains that AC should only be permitted in these specific circumstances:

Active cooling (air conditioning) will only be permitted where dynamic thermal modelling demonstrates there is a clear need for it after all of the preferred measures are incorporated in line with the cooling hierarchy.

This is due to the energy use of air conditioning units as well as their contribution to the urban heat island effect.

In addition to increasing the demand for energy, air conditioning and plant equipment expel heat from a building making the local micro-climate hotter.

Camden blocks AC installation purely for sustainability reasons

Unlike in other councils, in Camden AC retrofits can be refused purely on sustainability grounds.

For example, in this planning application (refused in 2023), there are no noise or design concerns:

The conservation officer was consulted and the air condenser units in this location in terms of design and heritage would not be considered harmful to the character and appearance of the host property or the wider conservation area.

…

Based on the results of the environmental noise survey, the applicant proposes adequate levels to be achieved at 1 metre from the nearest noise sensitive window

However, the applicants failed to take the necessary steps to demonstrate why air conditioning is necessary.

The proposal has failed to justify the need for active cooling by reducing and mitigating the impact of dwelling overheating through the application of the cooling hierarchy, thereby failing to minimise carbon dioxide emissions

In this case, the planning application failed to show that other steps of the cooling hierarchy were followed first, and didn’t submit a thermal model to prove that cooling was still required.

Does this policy really apply to existing homes?

London’s anti-overheating rules usually only apply to new developments. Is this the case in Camden?

When residents appealed the decisions of their local council, planning inspectors have not interpreted this consistently. For example, in this appeal from 2024, the planning inspector states:

However, I agree with the appellant that this requirement appears to refer to proposed buildings and to ensure that such new buildings are designed and modelled to mitigate the effects of possible overheating.

… the cooling hierarchy seeks, for instance, to reduce heat entering the building through orientation, and manage the heat within the building through exposed internal thermal mass and high ceilings.

These are all matters regarding the initial design of the building…

However, in another case from 2022, the planning inspector affirmed that Camden’s rules also apply to existing homes:

This policy is not restricted only to major developments.

The supporting text to the policy sets out that the Council will discourage the use of air conditioning and excessive mechanical plant as, in addition to increasing the demand for energy, such measures expel heat from a building making the local micro-climate hotter.

Newer guidance makes it clear it applies to all development

Overall, my impression is that the restrictions don’t just apply to new builds.

The Local Area Requirements for Planning Applications 2025 are most clear about this requirement:

All new-build development, and any development where air-conditioning is proposed, must demonstrate how the London Plan ‘cooling hierarchy’ has been applied and informed design. Development at risk of overheating (for example, single aspect units within 90 degrees of due south) should submit dynamic thermal modelling demonstrating risk of overheating has been mitigated.

Inconsistency in how the policy is applied

Camden’s unusual requirements have caused confusion for applicants. But planning officers have also not been applying the rules consistently.

For example, here air conditioning was approved without clearly demonstrating need:

Whilst AC units are not typically supported for environmental reasons, in this case the building is an existing dwelling with limited scope to retrofit

However, this precedent is not a reason to overturn the council’s planning refusal on appeal:

The appellant has submitted numerous examples of approvals within the Borough of similar recent development where a cooling hierarchy or thermal modelling were not required.

Such inconsistency in the application of policy is regrettable, however, this does not alter the clear wording and requirements of the policy before me.

Do you really need dynamic thermal modelling?

Notably, in this case a cooling hierarchy statement was submitted with the planning application in the example above. It mentioned several existing overheating mitigations, for example:

• Overhanging eaves

• Additional wall and roof insulation

• An efficient boiler to reduce internal heat generation

• Use of high thermal-mass materials

• Mechanical ventilation

The applicant stated that these measures “have not been effective in maintaining comfortably cool temperatures”, however this was not deemed sufficient:

A cooling hierarchy has been submitted by the appellant and I am satisfied that, as development serving an existing flat, the preferred measures set out in the policy and Policy SI 4 of the London Plan have been addressed.

However, no thermal modelling has been submitted and therefore the clear need for the units have not been demonstrated. The requirements of the policy have not been met.

Camden’s home improvement planning guidance is confusing

Camden’s home improvements guide from 2021 explains that air conditioning is discouraged and that other options should be “considered”. That’s a much weaker standard than what is sometimes required by planning officers.

If you are concerned that your home overheats in summer beyond comfort levels, you should consider passive cooling measures which do not rely on an energy source like air conditioning.

The guide explains that planning applications require a noise assessment and a statement of what other cooling measures have been taken.

Air conditioning units require planning permission and the submission should include a Noise and Vibration assessment as well the table in Appendix 1 completed stating all the other measures that have been taken to address overheating in your home.

This table is not specific to cooling measures. Dynamic thermal modelling is never mentioned in the guide. I can understand why someone might submit a planning application with just the documents outlined here, without checking additional council guidance.

Extensive effort, but still a technical breach

The Telegraph’s reporting mentions a case where an applicant successfully received planning permission on appeal in early 2026, a year and a half aftre their initial application.

The applicant documented numerous steps that were taken to achieve cooling through passive means, as well as submitting a dynamic thermal model to show that further cooling was required.

The council challenged the lack of ceiling fans and an MVHR+ system to achieve cooling without air conditioning. However, the applicant argued that these measures would not be effective:

Ceiling fans … will only have the effect of moving warm air around the room in any case

…

The installed MVHR system provides external air tempering by its very nature, it will exchange warm internal air and exchange it for cooler external air.

If the incoming air was to be mechanically tempered, this would require an outside air conditioning unit to run through an internal coil within the MVHR unit, this would constitute by very nature an air conditioning system.

Despite this, the planning inspector did not conclude that this clearly met Camden’s requirements:

The appellant’s commentary on the appeal scheme and measures already taken at the appeal property against the cooling hierarchy goes some way to explaining the absence of both ceiling fans and the MVHR+, both of which the Council consider should have been incorporated prior to the AC system.

I find the appellant’s reasoned justification in these respects to be compelling.

However, it seems to me that there remains limited technical justification for the 3 AC units and the need for that level of system to cool the building.

In the absence of such the appeal scheme would amount to a technical breach of the provisions and aims of CLP Policy CC2.

However, the appeal was ultimately granted because the extensive prior work showed a “continued commitment to the principles set out by the cooling hierarchy” and that installing AC “would not be inconsistent with the broad aims and provisions of those policies”:

Furthermore, although not decisive, it is clear that the extensive combination of measures and steps already taken, together with the AC system, suit the appellant’s particular needs and the constraints of a retrofitted property.

…

I am satisfied that material considerations exist sufficient to justify a decision otherwise than in accordance with the development plan.

This highlights that, when planning rules are rigorously applied, Camden residents need to go to extraordinary lengths to get AC approved.

Planning permission granted only with the cooling function of a heat pump disabled

When heating, heat pumps are significantly more efficient than gas boilers and their emissions go down as the electricity grid decarbonises. That’s why they are generally considered to be sustainable technology.

Reversible air-to-air heat pumps can also act as an air conditioner.

I found one case where a building extension was approved, however as one of the conditions the cooling option of the heat pump had to be disabled:

Prior to first use of the air source heat pump hereby approved, the active cooling function shall be disabled on the factory setting and the air source heat pump shall be used for the purposes of heating only.

Reason: To ensure the proposal is energy efficient and sustainable in accordance with policy CC2 of the London Borough of Camden Local Plan 2017…

Opposition to AC from local groups

It’s not just planning officers interpreting Camden’s AC rules strictly. The Hampstead Neighbourhood Forum also objected to air conditioning on sustainability grounds on several occasions.

For example, from a comment on one planning application:

We also question whether the applicant has provided enough justification for the proposed air conditioning unit, which is discouraged by Camden Local Plan Policy CC2, and wonder if the applicant has considered more sustainable heating and cooling methods as recommended by Camden guidance.

Or, from the planning application above where the cooling function was disabled:

The emerging Hampstead Neighbourhood Plan supports the green heating and cooling hierarchy, which emphasises energy conservation, followed by the utilisation of renewable energy sources and efficient technologies, to achieve environmentally friendly and sustainable heating and cooling systems. Active air conditioning would be contrary to this policy.

In a 2021 comment, The Camden Square Conservation Area Advisory Committee also expresses concern about the number of AC units proposed and their environmental impact:

There are two air conditioning units placed at the front and two at the rear of the property which seems an excessive number for the size of the flat.

…

The application form (under “Environmental Impacts” section) indicates that the units are heat pumps.

Whilst A/C units can be considered to be a form of heat pump. In this instance the form is for describing energy efficient air source heat pumps or similar, providing a positive, sustainable solution. However, air-conditioning units are not energy efficient choices.

Does this still matter after the 2025 changes to permitted development rights?

Permitted development rights allow owners to make changes to their property without requiring permission from their local council. Since May 2025, installing a reversible air source heat pump is allowed across England (including Camden), under certain conditions. Prior to the change, permitted development rights only applied to heat pumps that were “used solely for heating purposes”.

The current permitted development rules allow one heat pump per block of flats. However, in practice it’s difficult for an individual owner to get freeholder consent and comply with noise regulations. Flats account for 84% of homes in Camden.

There are also additional restrictions in conservation areas, which cover 70% of Camden’s built-up areas. There are 5,600 listed buildings where planning permission is still required.

This map shows conservation areas in Camden:

Overall, I think most people in Camden would still need planning permission to get air conditioning.

Permitted development doesn’t apply to cooling-only devices – but I don’t think that matters

Permitted development rights do not apply to pure air conditioning units:

Development is permitted by Class G subject to the following conditions… the air source heat pump is not solely used for the purpose of cooling

However, I get the sense that this doesn’t matter in practice since cooling-only devices are rare:

Modern air conditioning systems are reverse cycle heat pumps, not simple cooling units. Cooling-only systems are now very rare in the comfort cooling market.

Therefore, this requirement does not add any extra cost.

Camden’s new draft local plan

Camden is developing a new local plan and published a draft in 2025. Chapter 8, “Responding to the climate emergency” reaffirms that residents need to demonstrate the need for active cooling.

The chapter discusses overheating and cooling specifically:

…it is important to ensure that buildings and spaces in Camden are designed to promote cooling and reduce overheating, while avoiding the use of mechanical cooling, which often has significant energy requirements and, under conventional operation, expels hot air, which adds to the risk of overheating.

This will reduce the impact of overheating in the borough and reduce inequality in the experience of heat impacts.

The new policy CC8, “Overheating and Cooling”, takes a strong stance against air conditioning in new builds and clarifies that restrictions also apply to existing homes:

Proposals for active cooling in new residential developments are unlikely to be considered acceptable

…

[We will] only permit applications for new and/or additional active cooling systems or units where all other feasible measures in the cooling hierarchy have been integrated into the development and there is still a clear need for active cooling demonstrated by dynamic thermal modelling.

In addition to demonstrating need, applicants should also offset the energy use of AC through additional measures.

Where applications for active cooling are considered acceptable, the energy used to operate the active cooling system should be offset through the installation of solar PV and greening, to help cool the local environment, where feasible

This suggests that, unless permitted development rights apply, it will get even harder for Camden residents to install air conditioning.

However, these restrictions don’t apply when installing air conditioning in an existing property. What stops owners who want air conditioning from getting it?

Do you need planning permission to install air conditioning?

In May 2025, the UK government expanded permitted development rights in England. In many cases, it is now possible to install reversible air-to-air heat pumps without applying for planning permission, at least when a suitable site is available on the property. These heat pumps can provide air conditioning in addition to heating.

However, you still need planning permission in some cases. For example:

• Pure air conditioning units without heating

• Individual flats

• Listed buildings

In conservation areas (~10% of properties), you also still need planning permission for a street-facing installation.

Common refusal reasons in planning decisions

I used Landcycle to search for rejected planning proposals to install air conditioning units or air-to-air heat pumps.

Out of 31 applications I reviewed, 64% included noise as a refusal reason, and 48% mentioned design or local character. I wasn’t fastidious selecting a representative sample, but this analysis should give a directional idea of the challenges in getting planning permission.

The 2025 changes introduced tighter noise rules for permitted development. At the same time, siting rules were relaxed. I also included pre-2025 applications, so today I would expect slightly more noise refusals and fewer design ones for heat pump installations.

I’m mixing pure air conditioning units, reversible air-to-air heat pumps, and heating-only units in my review. However, assuming planning permission is needed in the first place, I don’t think this makes much difference in practice.

Noise concerns

To get planning permission for air conditioning units, property owners need to show that the noise and vibration won’t negatively impact neighbouring properties.

This is done using a BS4142 noise assessment. It looks at factors like how much noise the device can produce, how the noise travels, and how far away the neighbour’s closest door or window is.

If this assessment fails, planning applications generally get refused:

The proposed air source heat pump would generate unacceptable levels of noise pollution, causing significant harm to the living amenities currently enjoyed by neighbouring residents.

Design & local character

After noise issues, the visual impact of the air conditioning unit is the most common refusal reason, especially if the device can be seen from the street.

For example:

The proposed air source heat pump would be sited in a prominent position and would be readily visible from the street to the front of the property.

As a result, it is considered that the addition of the heat pump at the front of the garage would result in an incongruous addition that would harm the character of the property and wider street scene.

However, outside of conservation areas, ground-level front-facing heat pumps are now allowed under permitted development.

What about sustainability?

Recent reporting covered cases where air conditioning units were refused because climate change adaptation policies required applicants to demonstrate a need for air conditioning.

I’ve never seen this happen outside of Camden, despite spending quite some time looking. So it may not impact more than 0.4% of England’s population.

I’m hoping to write more soon about how Camden’s policies differ from those of other councils!

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.