Railway worker house

The solid brick wall, 60 cm thick and plastered on both the interior and exterior sides, was upgraded as part of the energy retrofit by applying 16 cm of internal wood fiber insulation. This was achieved by combining a 10 cm panel with a 6 cm panel. Particular attention was paid to ensuring a full-surface adhesive installation of the insulation in order to completely avoid any rear ventilation and to allow the wood fiber insulation to fully exploit its capillary-active properties. The airtight connection to the floor slab was also carefully executed. At the junction with the floor, where heating pipes run (previously installed surface-mounted), the inner 6 cm insulation layer was omitted over a height of 10 cm, creating a recess for routing the services, which was subsequently finished with plaster.

The wall was insulated from the inside, not only because, in the renovation of a single apartment within a multi-family building, this is effectively the only feasible approach, but also because it allows the characteristic external plaster to remain visible and unchanged.

The renovation upgraded the windows’ performance through repair and retrofit while preserving their historic character (e.g., box-type windows with the “Wolfsrachen” detail). It significantly reduced overall Uw (e.g., box-type windows from 2.1 to 1.05 W/m²K) without changing the original typology.

The intervention is conservation-compatible because it preserves the building’s historic features by refurbishing and upgrading the original windows (e.g., box-type windows with the “Wolfsrachen” detail) rather than replacing them.