geoff wrote:

Just a thought, phone up your local area authority and find out who they
use for council housing.

They should have filtered out the cowboys and have a reliable, fairly
efficient company. Whether you can get a good deal, and whether their
response time would be acceptable when they have a significant work
load, I don't know, try it and find out. It must at least be better than
picking a company who probably have their pet source of references.

What an excellent tip! Thanks Geoff.