The rule for calculating the area of ??the quota is based on the plane projection area. The stair surface is calculated according to the horizontal projected area of ??the stairs (including steps, rest platforms and stairwells within 500㎜) of the size shown in the design diagram. If there is a landing beam, the beam surface is included in the stair surface; if there is no landing beam, the stair surface is counted to the edge of the top step plus 300mm.

The engineering quantities of the tread skirting boards (facade panels) are incorporated into the quota sub-item of the floor tile stairs.

The expansion area of ??stair floor tiles (flat plate and skirting board) is 145m2/per 100m2 plane projected area