CO2 neutral buildings in CH-Männedorf - fully self sufficient

New Construction

  • Building Type : Collective housing < 50m
  • Construction Year : 2019
  • Delivery year : 2020
  • Address 1 - street : Saurenbachstrasse 8707 MäNNEDOERF, Switzerland
  • Climate zone : [Dwa] Humid Continental Hot Summer, severe, dry winter

  • Net Floor Area : 1 884 m2
  • Construction/refurbishment cost : 7 200 000 €
  • Cost/m2 : 3821.66 €/m2

Proposed by :

Certifications :

  • Primary energy need :
    40.07 kWhpe/m2.year
    (Calculation method : Other )
Energy consumption
Economical buildingBuilding
< 50A
51 à 90B
91 à 150C
151 à 230D
231 à 330E
331 à 450F
> 450G
Energy-intensive building

This building received a mention at the national and international levels for the Energy & Temperate Climates Prize of the Green Solutions Awards 2020-21.

The latest lighthouse project of Umwelt Arena Schweiz in cooperation with exhibition partners and the HSR Hochschule für Technik Rapperswil is the first residential building in the world with an intelligent and consistent combination of photovoltaics, battery storage, synthetic e-gas/biogas and intelligent energy management (hybrid box). All this at amortizable costs for the building owner and the residents receive heat and electricity at zero cost.  

A self-sufficient building with high-tech-eco-systems and products :

- A beautiful project realized by the owner of the Umweltarena in CH-Spreitenbach and designed by René Schmid Architekten AG in CH-Zurich. 

- The buildings produce 105'900 kWh per year by BIPV-elements,  PV-rooftop-installations, wind-turbine and other sources. The unused energy (summer) is transferred and turned into synthetic methane (which is CO² neutral) and can be re-electrified in winter. So the buildings produce more than consume.

- What is available as production and storage of renewable energies has been implemented.

- The tenants do not have to pay for electricity and heating. 

- Some of the BIPV-elements are white - which is unique and gives new architectural possibilities.


Data reliability


Photo credit



    René Schmid AG, CH-Zurich // Solaxess SA CH-Marin

    Mr. René Schmid // Peter Röthlisberger

Construction Manager


    Mr. Robert Grill



    Umweltarena, CH-Spreitenbach

    Mr. Robert Grill

Contracting method

General Contractor

Owner approach of sustainability

More information available at René Schmid

Architectural description

Very fonctional and ecological buildings with all comfort but without wasting energy. 16 flats of different sizes, close to the city-center of Männedorf. Clear in its modern forms. Autark in all aspects. Creative combination of activated facade-elements.

Ideal combination of power-generators and colors. A house looking similar to 1000 others - but having its huge and unvisible ecological and energetical qualities  

If you had to do it again?

Always with pleasure - with even more and newer technologies.

Building users opinion


Energy consumption

  • 40,07 kWhpe/m2.year
  • 75 502,00 kWhpe/m2.year
  • Other

  • 40,07 kWhfe/m2.year
  • Houshold: 43'357, Hotwater 15'849, Heating 16'296

    This buildings produce more than they consume.


    • Geothermal heat pump
    • Combined Heat and Power
    • Heat pump
    • Water chiller
    • Natural ventilation
    • Solar photovoltaic
    • Heat pump (geothermal)
    • Micro wind
    • Biogas boiler
    • Energy recovery from waste
    • Other, specify
  • 100,00 %
  • Photovoltaic system:
    A ventilated photovoltaic façade envelops the entire building. The building material (facade panels) was replaced with active photovoltaic elements. The photovoltaic panels are directly screwed to the substructure in wood. In order to make this simple installation possible, the photovoltaic modules have been specially prefabricated with mounting holes.
    White and dark, colored and textured photovoltaic facades like the ones we use in Männedorf serve as weather protection and energy generation at the same time.

    Synthetic Methane:
    Some of the excess solar power generated by the Männedorf superstructure in summer is sent to the power-to-methane pilot plant at the University of Applied Sciences in Rapperswil, where it is used to produce synthetic methane. This gas is CO2-neutral and is temporarily stored in the gas network, from where it is made available again to the residential complex in Männedorf in winter. There, the so-called Hybridbox® is used as the most important link, which, as an intelligent energy system, produces electricity and heat from the CO2-neutral "synthetic gas / biogas" as required.

GHG emissions

  • 40,00 year(s)


    Beautiful white solar modules

    Solaxess SA

    Peter Röthlisberger

    Gros œuvre / Structure, maçonnerie, façade

    With the unique color-giving technology of Solaxess PV-Modules are transferred into a construction material. Also in white and bright colors. No solar-cells are visible - even not from close.

    Loved by architects and construction companies.

Construction and exploitation costs

  • 9 000 000

Land plot area

2 879,00 m2

Built-up area

2,00 %

Parking spaces

The parking does also offer a CNG-filling station and charging station for EVs.

Building Environmental Quality

  • comfort (visual, olfactive, thermal)
  • energy efficiency
  • renewable energies
  • mobility

Building candidate in the category

Energy & Temperate Climates

Energy & Temperate Climates

Green Solutions Awards 2020-2021

 only renewable energies used
 white solar modules
 Green Solutions Awards
 smart building
 energy efficiency

Author of the page

  • Other case studies



    Green Solutions Awards 2020-2021