knocking shop 
noun British informal
A brothel.It'd make the back bedroom look like a bloody knocking shop....
- The old ‘one pub for every day of the year’ did actually hold true at one time, in the days when Walmgate and Fossgate were full of knocking shops and boozers.
- Even if we had a state-sponsored knocking shop in every town and village, there would still be prostitution elsewhere.