Range from the cheapest cat flap installation £120 (L & P Carpentry based in HP10) to the dearest cat flap installation £200 (Zamir Mohammed based in SL1).
Comparing carpenter & joiners estimates for installing a cat flap gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes to fit a cat flap in SL8 by posting a job with HaMuch and we will send it to carpenter & joiners in SL8.