Air conditioning in a leasehold flat: getting freeholder consent

Two permissions, not one

People often think planning permission is the hurdle. For a leasehold flat in London, the freeholder usually comes first. You own a lease on the inside of the flat. The freeholder normally owns and controls the outside walls, the roof, the structure and the common parts. An outdoor unit, a pipe hole and a cable run all touch things that are not yours.

So you will need written consent from the freeholder, and very often planning permission from the council as well. The two are independent. A yes from one does not give you the other.

Step 1: find the alterations clause

Dig out your lease and look for clauses about alterations, additions, the exterior, the structure and nuisance. You will usually find wording along these lines:

• no alterations to the structure or exterior without the landlord’s prior written consent
• no external fixtures, aerials or apparatus without consent
• no nuisance or annoyance to other occupiers, which can cover noise
• an obligation to pay the landlord’s costs of considering a request

Note whether the lease says consent “is not to be unreasonably withheld”. That changes how much leeway the freeholder has. If the wording is unclear, a solicitor can advise. We are not able to give legal advice on your lease, but we can give you the technical details the freeholder needs.

Step 2: understand what a mansion block managing agent wants

Westminster has some of the best known mansion blocks in London: red brick Edwardian blocks in Marylebone and around Baker Street, the long terraces of mansion flats in Maida Vale, and stucco blocks near Hyde Park. Most are run by a managing agent for a freeholder company, often owned by the leaseholders themselves. They see a lot of air conditioning requests, and many have a standard list. Expect to be asked for:

Item	Why they want it
Make, model and dimensions of each unit	to judge size and appearance
Photos and a marked up drawing of the outdoor unit position	to check visibility and access
Pipe and cable route	to protect the structure and common parts
Condensate drainage plan	to avoid damp and leaks into other flats
Noise figure at the nearest window	to avoid complaints and nuisance claims
Installer’s company F-gas certificate and insurance	to confirm the work is legal and covered
Method statement and working hours	to manage disruption in the common parts

A complete pack the first time saves weeks of back and forth.

Step 3: pick a position the freeholder can accept

Freeholders are far more comfortable with a unit they cannot see from the street and that does not sit outside another leaseholder’s bedroom. In mansion blocks that often means a rear lightwell, a rear wall at low level or a flat roof over a back extension. Be careful with lightwells: the noise method under MCS 020 says a unit boxed in by more than three reflecting surfaces cannot meet the standard, so a deep, narrow lightwell may not work.

Step 4: the planning position in Westminster

Westminster has 56 conservation areas covering over 76% of the City, according to the council. Permitted development for heat pumps only allows one unit for a whole block of flats, and only if the block is wholly flats. Many Westminster mansion blocks have shops on the ground floor, which takes them outside the rules. So for most leaseholders in the borough, a planning application is the realistic route. Our guide to planning permission for air conditioning in London explains the rules in full.

Westminster also sets a demanding noise standard. Its noise technical guidance asks for plant noise 10 dB below the lowest background level, measured 1 metre from the most affected façade of the nearest noise sensitive building, where the area is already noisy. Your freeholder and the council will both look at this.

Step 5: the licence for alterations

If the freeholder agrees, they will usually issue a licence for alterations. This is a legal document that sets out exactly what you may install and on what terms. Common conditions include:

• the work matches the approved drawings and specification
• you obtain planning permission first, if needed
• work only happens in set hours
• you are responsible for maintenance, noise and any damage
• the unit must be removed if it causes a nuisance or when you sell, if the freeholder requires

Read it carefully before signing, and keep a copy with your property documents. A buyer’s solicitor will ask for it.

What it costs to get consent

The freeholder’s reasonable costs are commonly passed to the leaseholder under the lease. Those may include managing agent time, a surveyor’s review and a solicitor drafting the licence. Ask for an estimate before you send the full request. These costs are separate from the installation and from council planning fees.

What happens if you skip consent

Installing without consent can put you in breach of your lease. The freeholder can demand removal and claim costs. It can also cause delays when you come to sell, as the buyer’s solicitor will ask whether alterations were approved. It is not worth the risk for a unit you could probably get approved with the right paperwork.

How we help

We survey the flat and the building, find positions that work technically and are likely to be acceptable, calculate the noise at the nearest window and put together the technical pack for your managing agent and the council. The flat air conditioning page explains the process, and the Westminster area page covers the local housing and planning context.