Cooling-only vs heat pump air conditioning: why it matters for planning
This is the single detail most likely to catch out anyone installing air conditioning in England right now: whether your unit can heat as well as cool decides whether you need planning permission at all, and it’s a distinction a lot of general “air con planning permission” guidance still gets wrong.
The rule, plainly
Since the May 2026 changes, permitted development for air conditioning outdoor units only covers heat-and-cool (reversible) systems, the kind that work as a heat pump in winter as well as cooling in summer. Cooling-only units fall outside permitted development entirely and need a full planning application, regardless of size, position, or how discreetly they’re mounted.
This isn’t a minor technicality. It means two visually identical outdoor units, one heat-and-cool and one cooling-only, can have completely different planning requirements on the same wall of the same house.
Why councils are enforcing this now
Over the summer of 2026, a number of councils began issuing removal notices against cooling-only units that had been installed without the planning application the rules now require. That’s a meaningful shift from the assumption a lot of people (and some installers) still work under, that any small outdoor unit is automatically fine. It isn’t, if it’s cooling-only.
If you’ve already had a cooling-only system fitted without permission, that doesn’t necessarily mean it has to come down, but it does mean it’s worth checking your position with your local planning authority rather than assuming it’s covered.
What this means before you buy
The practical takeaway is simple: specify a heat-and-cool system, and this whole question goes away, because it’s back inside permitted development (subject to the size, unit-count and noise rules covered on our main planning permission guide). Choosing cooling-only to save a relatively small amount upfront can mean a planning application, a wait for a decision, and the enforcement risk described above.
Our approach
We specify heat-and-cool systems as standard, not cooling-only, precisely so this doesn’t become a problem for our customers. We also run the noise check every genuinely permitted-development installation now needs. Between the two, most of our customers stay inside permitted development without ever having to think about it. If your circumstances mean a planning application is still needed, we’ll tell you clearly during your quote, not after the unit is on the wall.