FAQ

The environmental factors of a dwelling are evaluated using the environmental indicators I_env and I_prim. The I_prim indicator quantifies the primary energy needs of building materials and technical installations over a period of 30 years. The I_env indicator quantifies the environmental impact of a building material or element based on the following environmental impacts:

• global warming potential (GWP);
• ozone depletion potential (ODP);
• photochemical ozone creation potential (POCP);
• acidification potential (AP);
• eutrophication potential (EP).

The following criteria also determine the environmental factors of a dwelling: 

• the use of wood from sustainably managed forests;
• reducing the consumption of drinking water and the quantity of waste water;
• use of renewable energy;
• self-consumption of local production from the photovoltaic system;
• reduced electrical consumption of household appliances. 

In general, it is the owner of the building or the co-ownership management body that submits the request for aid for obtaining a sustainability certificate. 

A developer is therefore eligible for financial aid if, at the time of application, they are the owner of the building (or hold a share of the building). The establishment grant will no longer be available to future owners of lots for which the developer has already received financial aid. 

The amount of the establishment grant is as follows: 

• if the developer is a sole proprietor and if the “vertical land registry” (a descriptive statement on the division of the private lots and the common parts of a building under a co-ownership regime) has not yet been created: establishment grant of €1,500;
• if the developer is the sole owner and if the vertical land registry has been created: establishment grant of €750 per apartment/housing unit without exceeding the actual costs. 

A LENOZ certificate can be issued for all residential buildings with an energy passport, whether they are new or existing residential buildings. Issuance of the certificate is associated with Class 4 "minimum sustainability" (Chapter 0.2 of the Annex to the Grand Ducal Regulation on housing sustainability certification). Existing residential buildings can achieve this "minimum sustainability" by means of comprehensive retrofitting works.

An invoice with certificate of conformity and estimate/detailed explanation should be provided by each company involved in carrying out the work.

In order to simplify administrative matters, the certificates of conformity provided by the Environmental Administration can replace the detailed specifications/explanations and certificates of conformity of companies. The related invoices must be attached.

The certificates complementary to the Environmental Administration NCLD sheet can be downloaded here.

The certificate is valid for a maximum period of 10 years from its date of issue. The expiry date of the certificate is stated next to the date of issue.

In addition, the LENOZ certificate expires when the energy pass for the residential building in question expires.

In the case of a property in co-ownership, all co-owners must sign the application form for financial aid for the certificate process. The co-ownership management body can submit the application on behalf of the co-ownership.

A LENOZ certificate is issued for all buildings or parts of buildings that have a residential building energy performance certificate. The same definitions of residential and non-residential buildings apply to the LENOZ certificate and the energy passport.

A LENOZ certificate can be issued for all residential buildings with an energy passport, whether they are new or existing residential buildings.

Issuance of the certificate is associated with Class 4 “minimum sustainability” (Chapter 0.2 of the Annex to the Grand Ducal Regulation on housing sustainability certification).
Existing residential buildings can achieve this "minimum sustainability" by means of comprehensive retrofitting works.

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.