To all the STW builders out there. My attic is already a room - it has an original proper staircase upto it, has original floorboards and has got two velux windows. As far as i know, it has always been a room since the house was built in the late 1800's. I now want to sort it out properly, re plaster, decorate, and have it as the master bedroom. What are the requirements for a bedroom with regards to building regs as seen as it has always been a room? It is on the 3rd floor, so does it need fire doors and a minimum level of insulation?