It has been known for structures that break planning regulations to be knowingly erected in this borough. The owners/builders keep the work well covered until completion of all work and only then seek retrospective planning permission. I know of a case where there were local objections to a structure which clearly broke planning regs but Southwark Planning did diddley squat, not wanting to rock the boat. The owners just wait until four years is up and the extension can stand and no action can be brought against it. Builders know about this loophole and arevery happy to exploit it.