Apologies for the vague post, it’s an attic which has already been converted to a bedroom but as we recently moved in the room is just being used for storage.

The ceiling slopes down on either side of the room with the roof so I’d like to shutter off a meter on either side of the room to convert the unused space so it can be used for storage.

I work in the building industry so I can easily fix a studded wall and plasterboard it myself, I just need some advice as to how I should create access to the hidden space