FAQ

In general, the environmental indicators I_env and I_prim are calculated automatically (from the database implemented in the Lux-Eeb-H software) when filling in the calculation sheet for the thermal transmission coefficients of the different layers making up the thermal envelope (U value).

Section 7.3 of the Annex to the Grand Ducal Regulation on housing sustainability certification uses the I_env indicator for different constructions. Current data on building materials, recorded in the LuxEeB-H software, can be viewed in the Materialdaten LENOZ 2016 document on the website http://www.ml.public.lu/fr/lenoz/Experts/index.html.  

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 Ministry of the Economy regularly checks the calculations. The experts concerned can therefore be reported to the Ministry of the Economy or to Klima-Agence.

The Ministry of the Economy regularly publishes a list of approved experts who have undergone specific training: www.guichet.lu/experts-energie.

In addition, it is also possible to obtain a list of approved experts from the OAI. If in doubt about an expert's accreditation, you can ask for their accreditation documents or contact the Ministry of the Economy.

Yes, the EPC training courses developed by the Ministry are open to everyone, including municipal employees. They can be booked on the Internet portal www.guichet.lu/experts-energie. In addition, in 2017 a workshop was organised on the subject of site inspections led jointly by the Ministry of the Economy, Klima-Agence and Syvicol. Klima-Agence is also prepared to strengthen its collaboration with the municipalities. If necessary, the municipality can contact the qualified adviser at Klima-Agence. Some additional EPC training courses are also available on the main Luxembourg training portals.

The deviations must be documented and the main contractor must be notified of them. The municipality has the right to request additional calculations and/or documentation. The "as built” EPC indicates whether the minimum requirements have been met despite the deviations once the building is completed. As with any non-compliance with the building permit, the municipality can demand that the construction work required to ensure compliance with the EPC be carried out during the construction period and call the police if necessary.