Much less material is used than in conventional building and the labour cost is a fraction of the normal rate because unskilled labour can be used to do the work of otherwise expensive artisans. For standard openings (windows/doors) Stumbelbloc may be used in place of lintels – saving time, money and procurement/delivery costs. Finally, the use of Stumbelbloc eliminates almost all building waste. Any surplus standard mortar can be used to make more blocks.