Air conditioning installation in West Hampstead

The real obstacle in NW6 is paperwork, not pipework

West Hampstead is one of the easier parts of North London to install in, technically. Rooms are a sensible size, ceilings are reachable, and Victorian conversions usually offer at least one workable route to an external wall.

What makes NW6 different is ownership. A large share of the housing is leasehold flats in mansion blocks or converted terraces, which means the wall your condenser needs to sit on is not yours. Getting that resolved properly, in writing, before work starts is the difference between a smooth installation and an expensive argument.

How the consent process actually runs

Most leases contain a clause requiring landlord consent for alterations affecting the exterior or the structure. Fixing a condenser bracket to a rear elevation is squarely within that.

The sequence I recommend:

1. Survey first. I identify one or two viable condenser positions and specify the exact unit. Without this, you are asking the freeholder to approve something undefined, and they will say no.
2. Submit a proper pack. Position marked on a photograph, dimensions, weight, sound data, fixing method, and my F-Gas and insurance details. Vague requests get refused; specific ones usually do not.
3. Check the planning position in parallel. Flats have no permitted development rights, so an application to Camden is likely. The two processes can run alongside each other.
4. Install once both are in hand. Typically one to two days for a single room, three to four for a whole flat.

Allow four to ten weeks for consent and planning, and roughly a week for the work. Anyone who tells you a leasehold flat can be done next week has not read your lease.

Working in Victorian conversions

Converted terraces in NW6 have their own quirks. Original chimney breasts and stud partitions from the conversion can both be used to hide vertical pipe runs. Floor voids between flats are usually off limits because they belong to the building rather than to you. Bay windows and the returns beside them are often the cleanest place to bring a pipe run through.

Where the flat has been converted badly — and some were — the survey is also the moment I find out what is actually behind the plasterboard. Better then than mid-install.

Sizing for smaller rooms

A common and expensive mistake in NW6 flats is over-specifying. A 5kW unit in a 14 square metre bedroom will cool the room in four minutes, then short-cycle for the rest of the night: noisy, inefficient, and hard on the compressor. Most bedrooms here want 2 to 2.5kW, most through-lounges 3.5 to 5kW. I calculate it from room volume, glazing, orientation and heat gain rather than guessing from floor area.