Would you need planning for 2 heat pumps?

[tight fart]

My new next door neighbour has fitted 2 heat pumps to the roof of his out building that is beside our garden.
Would he need planning for this?

[Equus]

Almost certainly, yes.

The criteria and conditions for installation of air source heat pumps under Permitted Development are HERE.

Unless his installation meets all these criteria and conditions (and for two external units, I'd expect him to exceed the volume allowance listed under item (d), if nothing else), then he will require Planning Permission.

[Pheo]

I think it’s fair to say that with such a big push I suspect a lot of folks will assume that they are permitted development like a gas boiler and not really think about it.

[Equus]

The other thing to check is the MCS Planning Standards (referred to in the link I gave above), which give further, detailed standards including on the location of the external units and their allowable noise levels.

[Sheepshanks]

I know they can be effectively the same thing, but they look more like air conditioning evaporators.

[Dr Interceptor]

That will very likely need planning permission on two grounds;

1. the fact that it's two units
2. the possibility that they have been installed with any part of the unit within 1 metre of the edge of a flat roof (hard to tell from the photo, but possible given the layout).

[tight fart]

Thanks for the replies, if they are air conditioning units it would be because he wants to use the outbuilding as a commercial office.
I’ve emailed the council to find out.