Hi - am new on here and have searched this site and others for an answer to my question, but cannot find one. We want to build a rear extension on our detached L-shaped house. The L-shape is at the rear, so there are two two rear walls, staggered from each other with a 4m long wall separating them. Are we allowed to build 4m away from the furthest wall, or would the extension have to be 4m from one wall, and 4m from the other wall - i.e follow the line of the house? If we can only build 4m out from the closest wall it would simply square our house off. Thanks in advance for any replies.