Hi, I've had an offer accepted on a split floor flat that is a period property on a council leasehold. It has a basement floor and raised ground floor. There is one other flat above us. Directly outside the the basement bedroom window is a manhole which we found after a second viewing but didn't really understand how difficult it would be to move if we wanted to extend. Instead of doing a full extension, we are now wondering if we can extend an existing terrace to create a balcony which would be directly one floor above the manhole. I can't find any information about building balconies over manholes. There is already a small terrace over the bathroom - see images attached. Label A is where the proposed balcony/ terrace extension would be and label B is where the manhole is. Thanks