The building is a symmetrical structure with two wings, which frame the forecourt of the Lazaristenkirche. The north wing was the subject of renovation. It dates from the late "Gründerzeit" period of 1884-1918, was built in 1904 and designed by architect Cajetan Miserowsky. The renovated building is located on the north side and has a predominantly south-facing orientation of the habitable rooms. The north side to the adjacent Sophienspital is a closed firewall. The narrow side to the west faces the private garden.
The architectural quality in particular the appearance of the main façades with clinker surfaces, the historic windows & dormers, the house chapel and the shape of the roof were worth preserving. An innovative package of measures for the preserved Gründerzeit house was conceived as follows: The Viennese box windows in the articulated facades covered with ceramic tiles were preserved and supplemented with passive-house-fit internal wooden windows and energetically optimized. The thermal quality of the building envelope was enhanced by an interior insulation with calcium silicate panels. A comfort cover with a central ventilation unit and heat recovery for the living and recreation rooms was integrated into the historic building fabric.
Through a monitoring of the Vienna University of Technology, the demonstration project was scientifically monitored over a period of 2 years. By applying this innovative package of measures, it was demonstrated how a listed building can be adapted to a highly efficient and up-to-date standard of comfort and energy consumption.
The existing facade was made of ceramic clinker tiles. Conservative measures such as substance-saving cleaning and repair of the facing brick surfaces. Articulated facades and profiled plaster surfaces, such as cornices, window casings, window roofs and ornamented roof gable incl. Figural representations were repaired and restored as follows:
- Manual removal of various later lime-cement coating
- Surface cleaning, mechanical manual exposure of various decorative elements
- Stabilisation of the sanding surface, closing of cracks
- Plaster additions with cement-free natural hydraulic finished product
- U-value (pre-intervention) [W/m2K]: 0,917W/m²K
- U-value (post-intervention) [W/m2K]: 0,444W/m²K