Low-Energy Building
Low-Energy Building
Low-energy house ‘Müller’, Rottenburg, Germany.

Although just a few years ago low-energy buildings were considered especially ecologically advanced, today they belong to the new building standard in Germany.

Heating needs of buildings in kilowatt-hours per square meter per year:

Low-Energy Building 40 – 79 KWh/m²*a

Three-Liter-Building 16 -- 39 KWh/m²*a

Passive Energy Building max. 15 KWh/m²*a

Zero-Energy Building/Energy-Producing Building 0 KWh/m²*a or energy surplus

Existing Buildings Depending on Insulation 80 – 300 KWh/m²*a

In this case, a quantity of heat corresponding to 10 KWh =: 1 liter of heating oil, 1 m³ of natural gas or 2 kg of wood (holzpellets??? Maybe charcoal??). Therefore, in a low-energy building only about 4 to 8 liters of heating oil would be used per square meter of living area each year.

This classification doesn’t have anything to do with the construction of low-energy buildings. For example, a one-bedroom apartment within a large complex and with an un-shaded south-facing window could, without special construction, reach the status of a passive building. On the other hand, for a single family house with a large south-facing outside surface area (i.e. a roof-top balcony, or bay windows) that is shaded by another building or trees and is also exposed to wind, substantial insulation would be needed in order to meet the energy requirements of a low-energy building.

Because the concept of a low-energy building is not explicitly explained by law, banks and construction financing companies require a heating demand identification for such buildings. When awarding low interest rates for building loans on low-energy buildings, specific measurement limits are imposed depending on the type of loan. Of late, even heat gained by solar means, from a solar water or space heating system for example, can be included in the calculation of the yearly heating requirements.

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