Total centre line length =(4+.25)×2+(3+.25)×2=15m Height of wall = 4 m Thickness of wall = 0.25 m. Window area =2×2×1.5=6m2 Door area =1.5×2.2=3.3m2 Total opening area = where no need of brick work =6+3.3=9.3m2 Net effective area, where brickwork is to be done is given as: = (Centre line length) × Height – opening area =15×4−9.3=50.7m2 Qty of brick work = (effective area) × Thickness of wall =50.7×0.25=12.675m2