FAQ

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 installation of an electricity meter is compulsory in order to be eligible for State subsidies. This meter must measure the total consumption of the heat pump (including auxiliary consumption, such as for the circulation pump and the heating body).

Using the consumption data, you can also determine whether the installation is working efficiently and, in the event of deficiency, have it examined by a specialist as soon as possible.

The operator of a facility – in this case, you as an individual – is liable for the construction and operation of the facility in compliance with the applicable provisions and for all damages that may result therefrom. You should therefore check carefully that the drilling documents are complete. These should include:

the completed pressure test form as proof of the tightness of the geothermal probe once the probe has been placed (ask the drilling company if this report complies with VDI Guideline 4640);
the complete drilling report.

No. The Law of 19 December 2008 on water prohibits the direct or indirect discharge of water as well as other solid or gaseous substances. Groundwater heat pumps cannot therefore be authorised in Luxembourg.

• 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.