Have discovered under laminate flooring in extension in property a drainage inspection hatch. Have not opened it but outside there is a new drain hatch in the floor about 10 inches across with an openwork grid cover and inside is another pipe which has a cover which looks as if it can be opened to gain access to flush out or put a rodding pipe down. Is the original inspection hatch in the property therefore legal. Does not seem to have been any problem previously but before putting down new flooring wanted to make sure it is legal and safe.