Energy consumption in buildings currently accounts for over 40% of all energy consumed in Europe. This is by far the greatest share of total energy consumption, ahead of transport and industrial production. Approximately 85% of the energy consumed in buildings is attributed to heating and hot water generation, which means that the potential for energy savings is huge: according to the EU Commission, the energy efficiency of European building stock can be increased by 50%. Improvements can be made not only to heating systems and other technologies, but also in the area of insulation. Higher targets for energy savings and reduced CO2 emissions can be achieved by combining perfectly co-ordinated components to create efficient, fully integrated systems.
Of particular note is the potential for making heating systems (for room and water heating), air conditioning and lighting more energy efficient using the following technologies, in order to attain the energy standards of low-energy houses and passive houses:
- oil and gas heating (for example, condensing boiler technology)
- heat distribution (for example, pumps), heat emission (for example, radiators and underfloor heating systems) and controls (for example, valves)
- ventilation technology (for example, ventilation devices with heat recovery)
- air-conditioning technology
- combined heat and power generation
- heat insulation (energy-efficient products and components)
- lighting technology (for example, daylight redirection systems)
Another option is to replace conventional fossil fuels, such as oil or gas, or combine them with renewable energy sources. Finally, renewable energy resources are available in almost unlimited quantities and provide options for long-term, sustainable energy as they reduce our dependence on fuels that have a limited supply. Renewable energy sources also make a valuable contribution to environmental protection and climate control because they significantly reduce CO2 emissions.
The key application areas for renewable energies in buildings are as follows:
- solar thermal technology for domestic hot water and/or to support heating systems
- photovoltaic technology to generate electricity for domestic use or for grid supply
- innovative wood-burning solutions, for example, using split logs, wood pellets or wood chips
- solutions that leverage environmental heat or near-surface geothermal heat, for example, using heat pumps for heating
Germany has an established tradition of energy saving that stretches back at least as far as the oil crises of the 1970s. Since then, German regulations have been placing increasingly stringent demands on heating insulation and heating systems. The German Energy Saving Ordinance (EnEV) has been in force since 2002 and was amended in 2007. The EnEV envisages a holistic view of the building envelope, systems engineering and the preparation and conversion losses of the fuels used. A further planned amendment of the EnEV aims to tighten the rules on energy consumption in buildings by 30% before 2009.
For several years, the Federal government's energy saving regulations for buildings have been accompanied by its concerted promotion of the research and development of innovative technologies for the "buildings of the future", which allow standards to be raised.