Synergistic Energy and Comfort through Urban Resource Effectiveness (SECURE)

In Switzerland (and many other countries) around 75% of the population live in urban areas. These often contribute disproportionately to energy consumption (principally in buildings), and also frequently become uncomfortable and unhealthy (and hence unproductive) environments. There is a need for better methods and tools for the design of new districts and the renewal of existing ones. These should enable effective use of the resources available (land area, solar gains, air flows) to achieve synergies that benefit both energy use and comfort.

There are two principal natural driving forces for the urban environmental system: atmospheric (governing wind, temperature and humidity) and solar (affecting daylight, heat gains and power generation). Also, the system should be considered at two scales: district-level (capturing relationships and interactions between buildings) and building-level (abstracted in a simplified manner where appropriate). The two significant performance objectives related to urban environments (energy and comfort) must consider the combined impacts of both driving forces at both scales in order to achieve complementary results.

Efficient methods of searching the design space are needed to achieve effective use of limited urban resources. These resources form the constraints of a holistic optimisation problem; the objectives are the goals of minimising energy use (CO2 emissions) whilst maximising comfort (thermal, daylight, perceptions), while constrained by limited resources. Computational optimisation processes (for example multi-objective genetic algorithms) are ideally suited to such design space exploration. The solutions identified by these detailed methods for typical urban design problems can be extracted and embedded in fast tools for use in early design stages.

The SECURE project will develop an analysis framework and associated tools for the holistic analysis and optimisation of urban energy, comfort and utility. It will combine modelling aspects concerning microclimate, district and building energy use, renewable energy generation, daylight, perception (e.g. visual comfort) and achievable utility (e.g. impact on productivity). The outcome will be approaches and tools that enable synergistic decisions that enhance both energy use and comfort, appropriate for designing whole urban areas rather than single buildings. The method will be applied to a specific case study (or studies) in collaboration with the industrial partner Amstein + Walthert, Zürich.

Key contributions

ETHZ Chair of Building Physics: Urban energy use, microclimate modelling, outdoor thermal comfort.

Empa Laboratory of Building Science and Technology: Energy modelling, co-simulation, optimisation.

EPFL Interdisciplinary Laboratory of Performance-Integrated Design: Solar, daylight and climate analysis, iterative decision tools, real-world testing.


Dr. L. Andrew Bollinger
Empa, Urban Energy Systems Laboratory
Überlandstrasse 129
8600 Dübendorf
Phone: +41 58 765 6183

Prof. Dr. Jan Carmeliet
Empa, Laboratory of Building Technologies
Überlandstrasse 129
8600 Dübendorf
Phone: +41 58 765 4118