In addition to weathering the exposure to wind, driving rain, and temperature fluctuations, exterior walls must also function as noise protection, thermal barriers, and fireproofing.

Exterior walls of sand-lime brick are especially efficient thanks to their functional separation. The sand-lime brick takes on the tasks of structural support, fire protection, and noise-proofing, while the insulation has high design flexibility and provides thermal protection in both winter and summer. Both layers can be optimized to the desired level of quality.

A double-wythe exterior wall made of two layers of solid masonry enclosing a layer of insulation and an air space. The air space must be at least 40 mm thick.