@chorister, @historytutor,
I would love to talk about climate change in a separate, dedicated, thread, but I would greatly appreciate it if we could please
keep this thread on topic.
Btw, I tried to sleep in the loft during the heatwave - I couldn't. A younger guest than us couldn't, either, and ended up sleeping on the couch on the ground floor, which would not be a feasible option for the grandparents.
The loft is already double glazed. We could look into triple glazing and into further insulation but we are sceptical much would change.
Unlike Camden or other councils, Wandsworth doesn't publish any details on its rules for air conditioning.
I found one
application which was accepted (in Balham in 2016)
These guys:
https://www.noisesolutions.co.uk/
carried out a
noise assessment
Another case was
this
The
noise assessment was carried out by these guys:
http://kpacoustics.com/
In both cases, units producing ca. 50dB of noise were considered acceptable. Maybe more crucially, in both cases no neighbour seems to have filed any complaints.