Switzerland’s buildings are responsible for about half the country’s energy consumption, and thus for the concomitant CO2 emissions. To reduce these, it is old buildings, in particular, that will have to be made more energy-efficient.
The construction, operation and maintenance of all buildings in this country are responsible for about half of Switzerland’s energy consumption. This is supposed to change in the future: the Federal Energy Research Commission wants all the approximately 1.6 million buildings in Switzerland to be heated without fossil fuels by 2050 in order to reduce overall energy consumption by half.
Compulsory Minergie standard for new buildings
Technologies for CO2-optimised buildings are actually in place. Standards such as Minergie and Minergie-P (cf. box) would only have to be implemented, i.e. to be made compulsory for new buildings. Yet since new buildings only rarely replace older buildings with higher levels of energy consumption, they do not result in lower overall energy consumption. If, however, a building constructed in the 1970s is renovated according to the Minergie standard, it will then consume four times less energy for heating and hot water.
1.4 million old buildings devour too much energy
All in all, some 1.4 million buildings in Switzerland would have to be either demolished or renovated. For this reason, Empa and its partners from the ETH Domain – the Paul Scherrer Institute, the ETH Zurich and the EPFL – as well as Swiss universities of applied science (for example, within the Competence Center for Energy and Mobility CCEM-CH), are developing energy-efficient renovation concepts and technologies:
1. Energy use. For low-temperature heat (heating and hot water), renewable energies must replace fossil energy sources, for instance by means of solar panels or the exploitation of ambient heat or waste heat.
2. Systems analysis. In the Retrofit project, a highly insulating building envelope was developed, in which facilities for the utilisation of solar energy and comfort ventilation are integrated. The energy consumption of a 50-year-old block of flats could be reduced to 10 per cent of the previous value.
3. Material and component development. Compact high-performance insulation components such as vacuum-insulated windows, aerogels and chemical heat storage systems store summer heat for colder periods with as little loss as possible.
