What does the Building Energy Act stipulate for multi-family houses?

What does the Building Energy Act say about existing buildings?

With regard to the Building Energy Act, the following applies to existing buildings: The exterior components of the building must not be altered in a way that worsens the building’s energy performance – provided that the area of the modified components exceeds ten percent of the total area.

The Building Energy Act also contains provisions for the extension and expansion of existing buildings as well as for listed (heritage-protected) buildings. Whether and to what extent the Building Energy Act applies must be assessed on a case-by-case basis.

Building Energy Act: What is stated in the energy certificate?

According to the Building Energy Act, an energy performance certificate must be issued not only during construction, renovation, or extension of a building, but also upon request when a building is newly rented or sold. The certificate documents the building’s energy performance using a color-coded scale. Exceptions apply to listed (heritage-protected) buildings and buildings with less than 50 square meters of usable space.

Depending on the calculation method, either a demand-based or consumption-based energy certificate is issued. The demand-based certificate contains information on the energy requirements of residential buildings, determined through a technical analysis of the building structure and heating system. It is required for buildings with up to four apartments for which a building application was submitted before November 1, 1977.

For new buildings, the certificate has been mandatory since 2002. The consumption-based certificate indicates the actual energy consumption of the building occupants over the past three years for heating and hot water. The cost of a demand-based energy certificate ranges from 100 to 350 euros, while a consumption-based certificate costs up to 150 euros.

Building Energy Act: Consumption-based or demand-based certificate?

For buildings with more than four residential units, as well as for non-residential buildings, the Building Energy Act allows a choice between consumption-based and demand-based certificates. If a building is used for mixed purposes, a separate energy certificate may need to be issued for different parts of the building.

If an energy consultation is desired or public funding is applied for, a demand-based energy certificate is required, as it provides greater accuracy compared to a consumption-based certificate, which relies only on historical consumption data.

According to the Building Energy Act, energy certificates may only be issued by state-recognized energy consultants. The certificates are valid for a maximum of ten years from the date of issue.