Hi, I have a large room upstairs that is currently used as both a study and cinema room which measures 7.75 x 5.93. I was hoping to build a room within this room to have a dedicated home cinema with a projector and in-wall speakers. This would involve new stud walls built to create a small 5 x 3.6m room, am I right in thinking that this would need building regs approval as there won't be a window (there are 3 windows in the main room) and will it not get passed as i've read that you shouldn't really have a room within a room because of fire regulations? I have drawn a layout that I was considering but just wondered if anybody had any insight into this before I take it further? Thanks.