How does it work with energy efficient homes?

In the 21st century and times of global warming, Energy Saving is becoming more and more important. Energy can be saved not only by energy-efficient appliances in the home, but already in house building. The term low-energy house can not be defined as binding. Much more the term is a description of a building standard, not a design or construction. Energy efficient homes are energy efficient compared to average buildings. The primary energy requirement is less than 60 kWh per square meter and must meet the strict requirements of the Energy Saving Ordinance

Design features of an energy-efficient house

An energy-efficient house is characterized by a number of design features:

  • Compact design by reducing the outer surface
  • optimum thermal protection
  • controlled ventilation
  • using renewable energies
  • high efficiency of the heating system

Just a few years ago low-energy houses were regarded as ecologically advanced construction methods. Today, the energy-efficient house is standard in new buildings. As already mentioned, the heating demand must not exceed the value of 60 kWh per square meter. The amount of heat of 10 kWh corresponds to one liter of heating oil, one cubic meter of gas and two kilograms of wood pellets. An advanced energy-saving house is the so-called passive house. This construction means a very good thermal insulation, a largely airtight building envelope and optimized building services. The heat requirement of a passive house is not higher than 15 kWh / sqm per year. By comparison, a new building constructed in accordance with the law requires three times the energy requirement.

Passive House - saving energy as in the future

The rising annual prices of raw materials are creating strong demand for the Passive House. Builders hope that they can do without a heating system completely, but the energy-saving model has some disadvantages. The concept of the Passive House provides that it can do without any active heat generation. Much of the heat demand is covered by passive heat sources such as the sun, household appliances and the occupants themselves. If the heating requirement is less than ten watts per square meter, there is no need for separate heating. The required residual heat is generated via a supply system with heat recovery. The ventilation system is a key component of the passive house. The building envelope is almost airtight, so that no heat can escape. The supply of fresh air is ensured by a separate air recovery system. Of course, all the rules have their price. The construction and acquisition costs of such a house are far above that of a conventional new building. The investment is worthwhile, however, the energy savings can be up to 90 percent .

Zero energy house - ecological living

The Zero Energy House wants to give its owners the independence of energy suppliers and rising energy prices. With the construction concept, the complete heat and electricity demand can be covered by solar energy. Compared to the passive house, however, the zero-energy house requires a great deal of technical effort in order to be able to realize the building, because the energy required is generated exclusively by solar systems. A good ventilation system and insulation of the roof and exterior walls with up to 30 centimeters of insulation are needed to make optimal use of the energy gained. Heating is not needed throughout the year. If the temperatures on extremely cold days of the wind fall extremely, can be reheated with hydrogen from a solar hydrogen plant. A Modern ventilation and ventilation system provides fresh air, while a heat exchanger uses the exhaust air to generate heat. So far, zero energy houses are a hint of the future and are rarely realized. For this reason, no reliable parameters for the real construction costs are available. A low-energy house costs about 1,000 euros per square meter, a passive house already costs 1,300 euros. The price for a zero-energy house could therefore be around 1,500 euros per square meter.

KfW subsidies

If you own a house for years, you will not want to sell it and build an energy-efficient house. Alternatively, however, you can renovate or modernize your existing house. Appropriately, there are subsidies from the "Kreditanstalt für Wiederaufbau (KfW)" with the programs "Wohnraum Modernisieren" (living room modernization & ldquo; and & quot; Energy Efficient Refurbishment & quot ;. The subsidies can be applied for if individual refurbishment steps or complete renovations are to be carried out, which improve the energy balance of the house. In terms of funding, the better the energy standard, the higher the funding. For individual measures you can receive subsidies of up to 50,000 euros and for complete renovations up to 75,000 euros. During the term, reorganizers will only pay the interest . The loan debt will be paid only at the end of the term.

Artikelbild: © Irina Mos / Shutterstock