The clear width between masonry wythes is limited to a maximum of 15 cm as stipulated under DIN 1053-1. The wythes must be anchored with rust-proof metal ties. The vertical spacing between the ties should not exceed 50 cm, and the horizontal spacing should be no higher than 75 cm. All free edges (around openings, corners, along expansion joints, and on the upper ends of the outer wythes) are to be given three additional ties per meter of length.

Masonry using thin-bed mortar must comply with the applicable building codes for stainless steel ties. Walls with wythe spacings higher than 15 cm must be executed using specially approved anchors.

The outer wythe of a double-wythe wall with an air space and insulation, must be provided with 75 cm² of vent holes for every 20 m² of wall surface. If core insulation is used, weep holes along the floor level of the outer wythe must be provided at 50 cm² for every 20 m² of wall surface.