Does dry lining reduce the size of a room?

Dry lining reduces the size of a room slightly because plasterboard and its fixing system are added inside the existing walls. The amount of space lost depends on the installation method. Dot and dab dry lining may add around 20 to 40 mm to each treated wall. A timber or metal framed system can add 75 mm, 100 mm or more, especially when thick insulation or acoustic materials are included. Double layers of plasterboard also increase the total depth. In most average-sized rooms, the reduction is modest and may be outweighed by improved insulation, straighter walls or better sound control. However, it can be more noticeable in narrow hallways, box rooms and small bathrooms. The proposed wall thickness should be measured before work begins.