Check with local building officials how thick the walls must have to be a habitable interior space. Also make sure existing roof trusses meet specified guidelines. The floors in converting a garage into a bedroom usually inclined outwards to drain, and by law have to be one step below the living space. Build the outer walls of the new room, using your planes to frame the openings of windows. Use planks 5 by 10 or 5 per 15 cm, depending on how much insulation required by local building authorities.
Place a vapor barrier over the existing converting a garage into a bedroom and floor, about 25 cm up. Install sleeping on the floor, assuming you are increasing the height. Use planks 5 by 10 or 5 per 15 cm, to bring the soil up to the rest of the house, remembering that over the sleepers also will place plywood 1.8 cm and some pavement positioned above the plywood.
Trace plumbing, HVAC (an acronym for heating, ventilation equipment, and air conditioning) and electrical installation before closing the walls and floor for converting a garage into a bedroom. A vapor barrier staple on new outside walls of the house. Install the outer blade, brick or stone shape that matches the rest of the house.