keoto | Energetic Concept Zero Emission, Seestrasse District, Zürich

Energetic Concept Zero Emission, Seestrasse District, Zürich

Building owner: UBS Immobilien AG, Basel
Project: zero emission retrofit
Period: October 2010 – Dezember 2012
Phase: Energy-Concept,
Characteristics: 400 m2 HybridCollector, 12 Boreholes
Architect: Baukontor Architekten, Zürich


Initial situation

The project’s major requirements were on the one hand a sustainable renovation of the buildings with respect to energy consumption and CO2 emissions, and on the other the provision of economical living spaces. Furthermore, the area should maintain and reinforce its intrinsic characteristics as a 1950’s – 1960’s original development. This project is therefore exemplary in its adaptation of old buildings for the 21st century.

KEOTO AG was inquired about and ultimately commissioned the renovation strategy. KEOTO’s responsibilities were both developing the strategy for the area as well as planning concrete steps, particularly in the development and implementation of a zero CO2 concept for the operation of the housing development. In order to achieve this, we turned to the methods and software developed by researchers at ETH Zürich. These gave us the possibility to assess the ecological and economical sustainability of this project more rapidly and correctly, so that the respective construction and renovation activities could be carried out more efficiently and sustainably.


The result was a renovation carried out in accordance with the highest aesthetic and economic requirements. Two geothermal heat pumps, which use 15 geothermal probes at a depth of 200 m as an anergy source, provide the heating requirements of the project. The probe field is in turn supplied heat from hybrid collectors on the roofs, which have a total area of 400 m2. The self-generated electricity supplied by these panels allows the development’s heating demand to be met while emitting less than 1 kg CO2/m2 on average throughout the year.