FAQ

Since 1 January 2017, every new construction of a residential building in Luxembourg must be a Nearly Zero Energy Building (NZEB) in terms of energy consumption. As a rule, the NZEB corresponds to the AAA energy classes. However, certain conditions relating to the construction location may cause variations in these energy classes.

• Demolition: sale of a ruin or a building that does not have a heating installation and which will be demolished after purchase.
• Inheritance or gift.

• New building: any building that is subject to a building permit application. (A feasibility study concerning the use of renewable energies should be appended to the building permit application.)
• Extension of an existing building.
• Modification of an existing building (building permit required), if the surface area of the modified element of the thermal envelope exceeds the surface area of the same existing element (walls, windows, roof, etc.) by 10% and if the modification has an impact on the energy performance of the building. (Issuance of an energy performance certificate for the new planned situation.)
• Substantial alterations to an existing building (without a building permit), if the surface area of the altered element of the thermal envelope exceeds the surface area of the same existing element (walls, windows, roof, etc.) by 10% and if the alteration has an impact on the energy performance of the building. (Issuance of an energy performance certificate for the new planned situation.)
• Change of owner or tenant.
• Demolition: sale of a building that will be demolished after purchase, if the building has a heating installation, exterior walls and a roof.
• Modification of technical facilities, if the modifications of these technical facilities exceed €1,500 (for a single-family house) or €3,000 (for a multi-family house).

The energy performance certificate is a regulatory obligation, therefore no subsidy is provided for its establishment.
The energy performance certificate is issued according to precise rules set out in the amended Grand Ducal Regulation of 30 November 2007 on the energy performance of residential buildings. It is valid for 10 years from the day of its issue. The issuance of an energy performance certificate and the information it contains shall not result in any direct obligation for energy retrofitting.

The energy performance certificate (EPC) or energy passport is the quality label that defines the energy performance of a residential building. The certificate provides information on the energy efficiency of residential buildings and thus allows comparisons to be made with other residential buildings. Thus, even without technical knowledge, the consumer can assess the energy quality of a residential building.

No, LENOZ is an optional certificate that provides information to the main contractor and the owner about the level of sustainability of a residential building.

The following persons are authorised to issue LENOZ certificates:

• architects and engineers within the meaning of the Law of 13 December 1989 organising the professions of architect and consulting engineer;
• accredited persons within the meaning of the Law of 5 August 1993 on the rational use of energy;

• energy consultants within the meaning of the Act of 21 April 1993 on the approval of natural persons or legal entities, private or public, other than the State, for the performance of technical study and verification tasks in the environmental field.

• The size of the installation must be calculated in accordance with VDI (Association of German Engineers) Guideline 4640. Ask your chosen drilling company for information on this subject.
  In addition, you can also have a heat load calculation and a geological survey carried out in order to establish the sizing.
• You must ensure that you have obtained all necessary permits before the works start.
• The exact date of the start of drilling must then be notified to the water management authority in advance. Ensure that the drilling company and the installer coordinate their schedules.
• Plan appropriate access to the site in advance.