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.

A sustainable dwelling for which planning permission is sought between 1 January 2017 and 31 December 2022 can be subsidised under the Klimabonus scheme if it achieves at least 60% of the maximum number of points that can actually be achieved per category for 46 LENOZ criteria in three categories.

The following requirements apply for sustainability criteria 4.1.1 and 5.8.1:

- 4.1.1. Environmental assessment of building materials:

• a minimum of 24 out of 40 points must be achieved;
• a minimum of 21 out of 40 points must be achieved for buildings with at least three floors above the ground floor;

- 5.8.1 Assembly and dismantling capacity:

• 2017: a minimum of 6 out of 10 points must be achieved;
• 2018: a minimum of 8 out of 10 points must be achieved;
• 2019: 100% subsidy for a minimum of 10 out of 10 points; 80% of the total subsidy for a minimum of 8 out of 10 points.

(Technical details regarding the LENOZ 4.1 and 4.2 criteria) (Technical details regarding the LENOZ 5.8 criterion)

The values of the I_eco12 indicator are provided for some commonly used insulation materials in Chapter 7.3 of the Annex to the Grand Ducal Regulation on the Certification of the Sustainability of Housing and can be reused.

In the event that other insulation materials are used, experts can calculate the I_eco12 indicator using the I_calc calculator, which can be viewed online 

The I_eco12 indicator is used to assess new insulation installed on an existing building and is taken into consideration in the following cases:

• in the case of sustainable energy retrofitting of elements of the thermal building envelope under the Klimabonus subsidy scheme;
• as part of the LENOZ certification of an existing retrofitted building.

The indicator I_eco12 represents the environmental impacts (I_env) and the impacts induced by the primary energy requirement (I_prim) of an insulation material, evaluated on an equivalent thickness of 12 cm. This results in an independent environmental assessment of the existing building, while taking into account the grey energy consumed by the insulation material.