The old rule was a metre from the boundary. A Victorian terrace in Sale Moor has a rear yard that might be five or six metres deep and walled on three sides — there was no point in it that was a metre from everything, so permitted development was simply unavailable and a planning application was the only route. That rule is gone. The unit can now sit against the yard wall, and streets that were closed to heat pumps are open.
The constraint that replaced it is noise, and in a terrace it bites hard. The sound assessment is taken at the nearest noise-sensitive premises, and in a terrace you have neighbours on both sides with windows a few metres from your yard. It has to be 37 dB(A) or below. Sometimes that means a different unit, sometimes different mounting, sometimes a different corner of the yard — and sometimes, honestly, it means no. We run the calculation before we quote so that nobody finds out the expensive way.
Party walls are the Sale-specific detail nobody mentions. A nine-inch solid wall between two Victorian houses transmits vibration well, so where the unit is mounted and what it is mounted on matters as much as how loud it is on paper. We use anti-vibration mounts as standard here, and we do not fix a unit to a party wall if there is any other option.
Then there is getting it in. No side entry means the cylinder, the radiators and everything else comes through the front door and down the hall. It is not a reason not to do the job, but it is a reason the job takes longer here than the same job in Hale Barns, and anyone quoting the two the same has not been to look.
