Range from the cheapest window sill replacement £436 (Crestshield Windows Ltd based in SE20) to the dearest window sill replacement £560 (Carpentry & Building Services based in SW2).
Comparing carpenter and joiners estimates for replacing a window sill 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 replace a window sill in SE27 by posting a job with HaMuch and we will send it to carpenter and joiners in SE27.

"2 Sash windows (4 panes) with rotten parts needing repair - SE24
"Window sill replacement out window sill, rotten - landing window - now causing a leak running down under stairs when rains. - SW4