It's not possible to replace the entire lengths of cable as they drop down from under the bedroom above. However, I propose to push them into the roof space of the single storey extension and attach the juction boxes in there. They would be accessible via the loft hatch.
We are extending our kitchen into the adjacent single-storey room. We have 3 sockets on the wall that is to be removed. These cables drop down from the ceiling space - the house is 15 years old. I don't want to get the floor up in the bedroom above the kitchen, so is it OK (within regs) to push...