Perimeter wall thickness is defined by Primary frame thickness; 100mm, 150mm, and 200mm. Only vertical studs are normally used, 2400mm high spaces on-edge 1m apart. Horizontal members may be employed to frame special openings requiring specialized panels or to reinforce some integral utility equipment.

Light: 50mm 1x1 or 1x2. 1x2 may employ utility pass-through cut-outs up to 50mm wide. 1x1 normally placed on outside edge of perimeter wall in combination with use of borderless interior panel system.

Medium: 50mm paired 1x1, single 1x2 on outer edge, or single 1x3.

Heavy: 50mm paired 1x1, 1x1 and 1x2 combo with 1x2 on outer edge, since 1x2 in middle, single 1x3 on outer edge, or single 1x4.