Board specification
Moisture, fire and acoustic grades typically add £3–£10/m² compared with standard wallboard.
Multiple layers
A second board layer generally increases the lining rate by £10–£17/m², depending on board weight and fixing pattern.
Geometry
Numerous corners, openings, reveals and service penetrations can increase fixing costs by 15–35%.
Ceiling work
Overhead installation commonly adds £3–£6/m² because of reduced output and greater handling requirements.
Working height
Mobile towers, podiums or repeated access moves can add £2–£8/m² where work is above normal room height.
Package size
Small or phased work areas can attract a 10–25% premium through repeated mobilisation, distribution and minimum-gang costs.