Hi all, Just wanted to get some ideas about how best to tackle DPC placement for my extension. Here is what it looks like now. The wall on the right, and about 20cm of the one on the left will be demolished (it's a single-storey), and the internal opening will be closed off. And here is the plan for the extension. The extension has a step-in of about 20cm, and closes off the internal opening, with a short wall extending to take the lintel for the new outside door. I'm a bit unsure as to the best order of doing things, but decided to block up the interior opening first just so the place is secure before I demolish the wall on the right and start on the extension foundations. Seems I should feed in the start of the DPC part-way under the opening I'm bricking up since it's ending up as an external wall from POV of BCO. The problem is that the existing DPC is about 10mm below the pavement outside, so I have to decide whether to somehow bring it up for the extension or lower the ground outside it. The opening to be bricked up has a *very* solid piece of concrete that looks a) Hard to break up, and b) an excellent base for the blockwork, I've dug down in the room to the left about 70cm and it's all bricks and concrete underneath, so I wondered if really should break it all up just for the sake of inserting DPC at the same level as the exterior wall. Any advice on what I can get away with would be great. I get the feeling if I ask BCO they will tell me I have to do this the hardest way possible. I prefer to take a bit of a risk not because I'm lazy, but because I don't want to weaken the foundations unecessarily just for the sake of compliance on some minor issue. Sorry I've rambled on a bit. thanks for any help.