In Höngg, on the sunny slope side of Zurich, instead of a single-family house, there is now a residential building with six apartments, designed following...
Apartment building in Zurich – Höngg
Architect Beat Kämpfen
“It is hoped that the possibility of combining a purely technical system with the aesthetics of architecture will lead to the increased use of building-integrated photovoltaic systems in facades.”
The implementation of solar architecture

In Höngg, on the sunny slope side of Zurich, instead of a single-family house, there is now a residential building with six apartments, designed following the “Plus Energy Building (PEB)” concept. The new building has an area about two and a half times the size of the old construction, but uses only half as much energy.
The apartment building is designed as a solar power plant. The prefabricated timber construction is optimally insulated and at the same time, the generous windows passively use solar energy. The roof and the facades are both completely clad with photovoltaic modules that produce more electricity than the house and its occupants consume. The facade installation is made with photovoltaic modules characterized by a decorative ceramic-printed modules with check patterns to avoid a “technoid” expression.

Ground floor

Extensive windows allow to optimize solar gains.

The building envelope is completely cladded with BIPV modules.

Building characteristics
  • Building typology
  • Construction type
  • Year of construction
    April 2018 to February 2019
  • Energy reference surface
    904 m²
  • Energy index
    36.7 kWh/m²a (heating and electricity )
  • Energy labelling
    Minergie-P ZH-516-P
Active solar surface  141 m²  339 m²
Active solar surface ratio  >75%  >75%
Peak power  25.1 kWp  42.3 kWp
Building skin application  Flat roof  Cold facade
Storage Electric battery 30 kWh
Energy production
Source: Kämpfen Zinke + Partner AG
Measurements in progress
Building skin
  • Application
    Standard modules are laid on a metallic support system
  • Description
    Flat wooden framed roof insulated with 41 cm of mineral wool
  • U value
    0.10 W/m²K
  • Fastening system
    Continuous fixing system (aluminum tracks)
  • Other

View of the roof with the photovoltaic installation (85 modules JA Solar JAM 60D00-295/BP 295 Wp).

  • Application
    PV cladding integrated in the cold facade
  • Description
    Wooden framed walls insulated with 32 cm of mineral wool
  • U value
    0.14 W/m²K
  • Fastening system
    Substructure with aluminium black profiles
  • Other
    A total of 313 facade modules were installed corresponding to a PV area of about 340 m². 24 different modules with PV cells and 8 different modules without PV cells were used.

The possibility of printing PV modules with different patterns opens up completely new design possibilities.

  • Application
  • Description
    Triple glazing with wooden frame
  • U value
    0.6 W/m²K
  • g value
  • Other

Close-up of the facade.

Aesthetically, the photovoltaic modules are practically indistinguishable from a standard cladding.

BIPV module
  • Product
    ISSOL Sondermodule (data sheet not available)
  • Manufacturer
    ISSOL Switzerland SA
  • Cell technology
  • Front glass type/customization
    Module stratigraphy: 4 mm glass with ceramic screen printing – mono-crystalline PV cells – backsheet – 4 mm glass
  • Cell Colour
    Orange, red, yellow, green
  • Dimensions
    Custom made
  • Power
  • Weight
Technical details

Already in the design stage, a grid was defined based on a multiple of the building length without remaining areas. This was also taken into account in the static system of the timber construction. The aim was to simplify and cut the costs by reducing the number of different module sizes.
The facade modules are arranged vertically in a 1 m grid. Vertically were used four module types, which result from the heights between roof, window and building base. In the balcony railing, the same modules were turned by 90°. Through the combination of various lengths can compensate the different volumes of the balconies, spacing between the modules can vary in order not to need additional formats.

Hotspot image
Vertical section – eave connection
Hotspot image
  • Total cost of the building
    5,8 Mio. CHF (BKP0-9) 4,84 Mio. CHF (BKP2)
  • Cubic meter price
    1,065 CHF/m³ (BKP2)

Details of the facade.

Parties involved
  • Owner
  • Photovoltaic consultant
    Sundesign GmbH
  • Photovoltaic Installer
    Planeco GmbH
  • Facade installer
    GFT Fassaden AG
  • Photo
    Kämpfen Zinke + Partner AG
Awards and recognitions
  • Awards
    Schweizer Solarpreis 2019 – Norman Foster Solar Award (Diploma)
  • Publications