Range from the cheapest cat flap installation £132 (Wandsworth Sash Windows based in SE26) to the dearest cat flap installation £340 (Bromley handyman based in BR2).
Comparing carpenter and 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 br3 1 au by posting a job with HaMuch and we will send it to carpenter and joiners in br3 1 au.

"Install a cat flap on side wall in conservatory. The wall is double ply Perspex"
BR3