For maximum space and resource efficiency, Haus 2+ uses what was available on site: Like a ‘friendly parasite,’ the addition shares the exterior stairwell of the neighboring concert hall, eliminating the need for its own CO2-intensive circulation space. It uses an existing basement as a floor slab and the district heating station inside as the main energy source. Its roof terrace integrates with Holzmarkt’s sequence of open arcades, bridges, and balconies. Haus 2+ combines three timber construction systems.

Exterior walls are made with timber frames, internal walls are made from mass timber, and floor slabs use timber box elements, all clad with a larch façade. Regionally prefabricated and screwed instead of glued, all components can be disassembled, segregated, and reused with little effort.