Air conditioning installation in Hampstead

Why Hampstead is harder than most of London

Most air conditioning quotes for NW3 are written by people who have never installed in a conservation area. They price a standard three-metre pipe run, assume the condenser goes on the nearest external wall, and discover the real constraints on the first day of work. That is when the change requests start.

Hampstead has three characteristics that change the job:

Solid walls, no cavities. Georgian and Victorian construction gives you nowhere to hide pipework. Every run has to be planned through cupboards, along skirting lines, inside bulkheads, or accepted as trunking that has to look deliberate. This is a design decision, not an afterthought, and it should be settled at survey.

Conservation area status almost everywhere. Camden operates around 40 conservation areas covering roughly half the borough, and most of Hampstead falls within one. That removes or restricts the permitted development rights you would rely on elsewhere.

Condenser positions are genuinely scarce. Terraced townhouses with no side return, basement lightwells with restricted airflow, mansion blocks where the freeholder controls every external surface. Finding a position that works thermally, acoustically and legally is most of the skill.

The planning position, honestly

There is a lot of confident misinformation about this, including on other installers’ websites. Here is the accurate version.

Permitted development rights for air source heat pumps do exist, and modern reversible split systems generally qualify as heat pumps because they heat as well as cool. But three conditions matter in Hampstead:

• Cooling-only units are not covered. If the system does not provide heating, permitted development does not apply and you need permission.
• Conservation areas restrict what is allowed, particularly on any elevation fronting a highway. Article 4 directions can remove rights entirely.
• Flats and maisonettes have no permitted development rights at all, anywhere. A large share of NW3 housing is flats.

There are also dimensional limits — the external unit must be within volume limits and set back from the boundary — and, from May 2026, a tightened noise standard under MCS 020 that reduces the permitted sound level at the neighbouring assessment position. That change matters most in exactly the sort of tightly-packed streets Hampstead is made of, because it affects how close to a boundary a unit can sit.

I check your property against all of this at survey. If it needs an application, I will say so, explain what is involved, and you can decide whether to proceed before any money changes hands.

What a good Hampstead installation looks like

The finished job should be almost invisible. Indoor units sized to the room rather than over-specced, sitting high on a wall where they do not fight the cornicing. Pipework concealed or, where it cannot be, run tight and straight in trunking that matches the wall. The condenser positioned where it is not seen from the street, not audible from a bedroom, and not blowing warm air at a neighbour’s window.

That takes longer to plan than it does to install. It is the reason my survey runs 45 to 60 minutes rather than fifteen.

Brands I fit in NW3

Daikin and Mitsubishi Electric for most residential work — both make units that run quietly enough for a bedroom, with the discreet wall cassettes that suit period rooms. Where budget or a specific space is better served by Panasonic, LG or Samsung, I will say so rather than pushing a brand.