A low-energy house is a residential or commercial building that reduces energy consumption to a minimum thanks to its design and the use of modern technologies. In Austria, as in many other European countries, the concept of the low-energy house has become increasingly important in recent years. This is mainly due to the fact that reducing energy consumption plays a central role in combating climate change and achieving national and European climate targets.

Essentially, a low-energy house is characterized by particularly good thermal insulation, efficient heating and cooling systems and the use of renewable energies. Austrian building regulations define clear standards for such buildings, with the annual heating requirement per square meter being the decisive factor. A low-energy house may consume a maximum of 50 to 70 kilowatt hours per square meter per year, while conventional buildings have significantly higher values. These standards contribute to a sustainable reduction in energy consumption and CO₂ emissions.

In Austria, the construction of low-energy houses is strongly supported, particularly in the context of housing subsidies. Numerous subsidy programs at federal and state level offer financial incentives for building owners who wish to invest in energy-efficient forms of housing. These programs aim to promote both new builds and the renovation of old buildings into energy-efficient homes. It is primarily private individuals who benefit from the subsidies, but companies and local authorities are also encouraged to construct energy-efficient buildings.

Thermal insulation is a central element of a low-energy house. The use of high-quality insulation materials on walls, roofs and windows minimizes heat loss. Windows with triple glazing, insulated doors and facades and an optimized building envelope are essential measures that are used in low-energy houses. This construction method ensures that less energy is required for heating in winter and that cooling is supported naturally in summer.

In addition to insulation, modern heating systems and the use of renewable energies play a central role in low-energy houses. In Austria, heat pumps and solar thermal systems are particularly widespread. These technologies make it possible to significantly reduce energy consumption for heating and hot water. Heat pumps use the thermal energy stored in the environment from air, earth or water to heat buildings efficiently. Solar thermal systems, on the other hand, convert solar energy into heat and thus contribute to the supply of hot water. In many low-energy houses, these systems are combined to achieve even greater energy efficiency.

Ventilation technology is also crucial in low-energy houses. By using controlled ventilation systems with heat recovery, a large proportion of the heat that is lost during ventilation can be recovered. Such systems make it possible to control the supply of fresh air and minimize energy loss at the same time. In countries such as Austria, where there are large temperature differences between summer and winter, these systems are particularly useful and help to further reduce energy consumption.

Another characteristic feature of low-energy houses is the increased use of photovoltaic systems to generate their own electricity. These systems convert sunlight directly into electricity, which can be used for the home's own needs or fed into the grid. In combination with storage systems, homeowners can further optimize their energy consumption and to a certain extent become independent of fluctuations in the price of electricity from the public grid. Particularly in Austria, where renewable energies play a central role in energy policy, the use of photovoltaic systems in low-energy houses is a rapidly growing trend.

The construction of low-energy houses brings not only ecological but also economic benefits in the long term. Although the construction costs for a low-energy house are generally somewhat higher than for conventional buildings, these investments are quickly amortized due to the lower operating costs and reduced dependence on fossil fuels. The savings on heating and electricity costs and the possibility of taking advantage of state subsidies make low-energy houses attractive for both private builders and investors.

Austria plays a pioneering role in Europe in the field of sustainable building. Strict building regulations and extensive subsidy programs are actively promoting the construction of low-energy houses. In 2020, the EU Buildings Directive came into force, which stipulates that all new buildings in the EU should be virtually energy self-sufficient. These requirements are being consistently implemented in Austria, and low-energy houses are a central component of this strategy.

In summary, it can be said that the low-energy house is a decisive step towards sustainable building and living. It not only reduces energy consumption and the associated costs, but also makes an important contribution to climate protection. In Austria, this construction method has become firmly established thanks to clear legal requirements, attractive subsidy programs and the growing demand for energy-efficient solutions. Low-energy houses are therefore not just a trend, but an important part of the future energy transition.