In Vienna, Energybase, Austria’s largest “eco-office house” is currently being built. The five-storey building with 7,500 square metres of usage space was designed as a passive house, which uses solar energy, geothermal energy for cooling and heating. This should reduce the energy costs by 80 percent compared with traditional building methods.

The obligation to reduce CO2 emissions by at least 20 percent by 2020 throughout the EU requires that buildings – whether residential, offices, retail buildings, hospitals, or production space – must be developed whose operations have a stable energy balance. In other words, they consume no more than they produce.

This is technically possible, through a united collaboration of a building’s alignment and design with its technical outfitting, as well as the use of renewable energy, such as geothermal energy, wind and solar energy. In Europe, and especially in Germany, this area of technology is considered advanced. Of course, the building costs for a building are then slightly higher than before, even when not as high as they were several years ago when this kind of building was considered exotic.

Even if all project developments become “green” and fulfil the well-known passive house standard particularly in the residential sector in Germany, the problem is not yet solved. The ratio of new to existing buildings is low, at 5 to 95 maximum. Existing buildings are “heavy users” of energy, and it will take years, if not decades, until the existing buildings are substituted or refurbished to become energy neutral. In other words, to reduce the energy need in the next 13 years, and thus reduce CO2 emissions, new buildings not only have to have a steady energy balance, but also produce more energy.