Brettstapelbau

Brettstapelbau, or board-stacked construction, is a timber construction method in which load-bearing walls are formed by stacking boards in horizontal layers. Each layer consists of boards laid edge-to-edge, and successive layers are typically oriented perpendicular to one another to produce a self-supporting wall panel. The system often does not require a separate heavy framing structure, as the walls themselves carry loads and contribute to overall rigidity.

Materials and joints commonly used in Brettstapelbau include boards that are typically 20–40 mm thick and of various widths, made from softwoods such as spruce or pine. Layers are interlocked by joints such as tongue-and-groove or end-notches, and corners may use notched connections or dowels. Walls can be assembled on site or produced as prefabricated panels and later clad or insulated to meet external requirements.

Applications and characteristics: Brettstapelbau has been used for single-family houses and, in some cases, multi-storey buildings, particularly in Switzerland, Germany, and Austria. Benefits attributed to the method include good thermal mass, favorable acoustic properties, resource efficiency, and potential for rapid construction. The approach is compatible with external insulation and various cladding systems and can be integrated with other timber technologies.

Challenges and considerations: Moisture management is crucial, as timber must be properly dried and protected to prevent warping or decay. The technique requires skilled workmanship and precise detailing for joints and connections. Availability of appropriate supply chains, expertise, and regional familiarity can influence feasibility outside its traditional markets.