The Environment Agency (Administration de l'Environnement – AEV) grants subsidies for energy efficiency renovation projects that are limited to a single construction element of the thermal envelope. The renovation works must be:

• either carried out by an approved business;
• or overseen by an energy consultant.

The Klimabonus scheme applies to sustainable energy efficiency renovations of residential buildings older than 10 years from the date of issue of the building permit.

For energy consultations carried out prior to 31 December 2021, the previous PRIMe House aid scheme still applies.

Financial aid for sustainable energy efficiency renovation projects may be received concurrently with aid available for the implementation of technical installations.

Who is concerned

Applicants concerned

Any person who wishes to improve the energy performance of their residential building, that is, any:

• natural person;
• legal person established under private law;
• public legal person other than the State.

You can submit your application in your capacity as:

• legal representative of a group of natural or legal persons, provided that you are a part of this group yourself;
• owner(s) of the dwelling, except when there is a change of ownership and the new owner of the dwelling and/or technical installation forgoes the aid in question for the benefit of the former owner who made the investments.

Works concerned

Financial aid may be sought, in particular, for:

• the insulation of roofing;
• the insulation of an external wall;
• the insulation of a ceiling slab in contact with an unheated attic;
• the insulation of the lower floor slab that adjoins an unheated basement or the floor, or the exterior;
• the insulation of a wall in contact with the ground or an unheated zone;
• the replacement of windows.

Prerequisites

Eligible buildings

The residential building must be older than 10 years from the date of issue of the building permit when the financial aid application is submitted.

The energy efficiency enhancement works must be:

• carried out by an approved business in accordance with the law of 21 April 1993; or
• occasionally monitoring by an approved energy consultant.

Technical requirements to be fulfilled

To be eligible for the subsidy:

• the renovated elements must not exceed certain heat transfer coefficients;
• the minimum thickness of the insulating material (performance standard III) must be complied with for all other performance standards;
• insulation materials must comply with the requirements of the I_eco12 ecological indicator.

From 1 January 2024, fossil-based insulation materials will be subsidised only if they are made from at least 50 % recycled materials;

• if the attic space is heated, the renovation of the roofing must also be associated with the replacement of the roof windows if the latter are more than 10 years old and do not meet the heat transfer coefficient criterion of 1.40 W/m²K;
• to prevent humidity due to condensation, and the ensuing problems (mold, etc.), the renovation of the windows may be subsidised, provided that:
  • the exterior wall or roof of the heated attic has a heat transfer coefficient that is less than or equal to 0.85 W/m²K, 0.80 W/m²K or 0.75 W/m²K, depending on the targeted performance standard; or
  • the building has a controlled mechanical ventilation system.

Requirements for enhanced construction elements

The minimum thicknesses of the thermal insulation materials shown in the table above apply to a heat conductivity of 0.035 W/(mK) for the insulation material. For other heat conductivities, the minimum thicknesses should be converted based on the actual heat conductivity of the insulation material.

^* The minimum thicknesses of the thermal insulation materials shown in the table above for external walls insulated on the internal side apply to a heat conductivity of 0.040 W/(mK) for the insulation material. For other heat conductivities, the minimum thicknesses should be converted based on the actual heat conductivity of the insulation material.

^** The requirements correspond to triple glazed windows and apply to a standard-size windows (1.23 m x 1.48 m). Conditions:

• either guarantee a certain heat quality of the external wall based on the targeted performance standard (U_wall ≤ 0.85 W/m²K, 0.80 W/m²K or 0.75 W/m²K);
• or have a controlled mechanical ventilation system.

^*** The minimum thickness of the insulation material (performance standard III) must be complied with for all other performance standards.

^**** If the loft space is heated, the renovation of the roof must include the replacement of the roof windows (if they are > 10 years old, and if U_W > 1.4 W/m²K)

^***** If both the internal and external sides are insulated, the insulation material applied on the external side must have a thermal resistance R of at least 2 (m²K)/W.

Some communes grant aid to supplement State aid for energy savings and renewable energies. Contact your communal administration or Klima-Agence for further information.

Deadlines

Applications for financial aid must be filed with the Single point of contact for housing assistance (Guichet unique des aides au logement) after the end of the works and within 4 years from 31 December of the calendar year to which the invoice relates.

The invoices for the energy efficiency renovation works must be issued between 1 January 2022 and 31 December 2029 inclusive.

The first application for an agreement in principle must be submitted between 1 January 2022 and 31 December 2025 inclusive.

Applications for financial aid for liquidation must be submitted no later than 31 December 2031.

For renovation works where:

• the first application for an agreement in principle is submitted between 1 November 2022 and 31 December 2023 inclusive; and
• the invoice is issued by 31 December 2025 at the latest;

the financial aid awarded will be increased by a financial aid bonus of 25 %.

How to proceed

Applications for the grant must be filed with the Single point of contact for housing assistance (Guichet unique des aides au logement).

Prior to the works: application for the agreement in principle

Prior to commencing the energy efficiency renovation works, you must obtain an agreement in principle from the Single point of contact for housing assistance.

To obtain an agreement in principle, you must submit your request:

• either online, via MyGuichet.lu or using the MyGuichet.lu mobile application (see 'Forms / Online services' below). This is a procedure with authentication that requires:
  • a LuxTrust product (Token, Smartcard or Signing Stick); or
  • an electronic identity card (eID).
• or by post (preferably by registered mail), or by handing in the dedicated form (see 'Forms / Online services') at the Single point of contact for housing assistance (Guichet unique des aides au logement):
  • if you are a natural person: the DEPA-2022 aid application form for natural persons; or
  • if you represent a legal person: the DEPA-2022 financial aid application form for legal persons.

The form must be accompanied by all the required supporting documents.

Once the agreement in principle has been obtained, you can begin the renovation works.

Note: If, based on the advice of the energy consultant or approved business, you change your renovation concept after obtaining the agreement in principle, you can file an application to obtain a new agreement in principle.

After the works: request for payment of the aid

Once the energy renovation measure is completed, you can request payment of the financial aid for energy renovation using the same procedure as for the agreement in principle detailed above (via MyGuichet.lu or paper form). To do this, you must use the form titled 'Confirmation of energy efficiency renovation of an existing residential building' (Confirmation rénovation énergétique d’un logement existant – CONF-2022) that is specific to the refurbished element. This form is provided by the approved business or energy consultant. This form must be accompanied by the required supporting documents.

Supporting documents

For the application for the agreement in principle, in addition to the DEPA-2022 financial aid application form (natural or legal person), you must also provide:

• the appendix form titled 'Description of the measure for the construction element' (Description de la mesure pour l’élément de construction – DESC), which indicates the planned renovation measure that is subject to the agreement in principle. This form must be duly completed and signed by:
  • the approved business; or
  • the energy consultant who monitors the works;
• a copy of the initial building permit for the building, or an official document certifying the age of the building;
• in the case of an extension/enlargement of the building's thermal envelope, building plans corresponding to the situation after the energy efficiency renovation works;
• a cost estimate or quote confirmed by:
  • the approved business; or
  • the energy consultant who monitors the works;
• if the application is for a commonhold property or a multi-unit residence:
  • appendix form COLL-2022;
  • a power of attorney from each owner;
  • the list of the flats, specifying the energy reference area per flat, excluding the common areas.

With respect to the application for the payment of aid, in addition to the form titled 'Confirmation of energy efficiency renovation of an existing residential building' (Confirmation rénovation énergétique d’un logement existant – CONF-2022), applicants must also provide:

• if you are a private individual: the DEPA-2022 aid application form for natural persons;
• if you represent a legal person: the DEPA-2022 financial aid application form for legal persons;
• copies of invoices that prove the eligible costs and proof of payment (notice of debit or invoice receipted in due and proper form). The invoices may refer to a detailed estimate, in which case the latter must be attached to the invoice; 
• the invoice for the occasional monitoring of the works by the energy consultant must include on-site verification of the compliance of the works;
  
• if the application is for a commonhold property or a multi-unit residence:
  • appendix form COLL-2022;
  • a power of attorney from each owner;
  • the list of the flats, specifying the energy reference area per flat, excluding the common areas.

The Single point of contact for housing assistance may ask you to provide any documents it deems necessary to process the file.

Amount of subsidies

Basic subsidy

The amounts are calculated based on the surface areas of the renovated elements. The area of the renovated element is multiplied by the corresponding amount shown in the table below.

* materials that do not fall under the definitions of categories (b) and (c)

** for insulating material placed only on the internal side, the specific financial aid [euros/m² refurbished] shown in the table above is reduced by 25 %; the requirement that mineral insulation material (category (b)), and eco-friendly insulation material (category (c)) be installed mechanically does not apply for insulation material placed only on the interior side.

Aid mark-up for the use of recycled materials for fossil-based and mineral insulation material

If mineral or fossil-based insulation materials made from at least 50 % recycled materials are used, a EUR 15 mark-up on the base subsidy is granted.

Aid mark-up for the use of eco-friendly insulation materials whose components are sourced from certified sustainable crops

If eco-friendly insulation materials whose components are sourced from certified sustainable crops are used, a EUR 15 mark-up on the base subsidy is granted.

Payment of financial aid

The aid is generally transferred directly to your bank account.

If you act in your capacity as a legal representative of a group of natural or legal persons, the aid is transferred directly to your bank account and you must immediately credit the bank accounts of the natural or legal persons concerned with their respective share of the aid.

A copy of these payments must be sent to the Single point of contact for housing assistance.

Repayment of aid

If you have already received the aid, you may be required to return it, if:

• you are found to have made inaccurate or incomplete statements in order to obtain the aid; or
• you fail to provide the Single point of contact for housing assistance with the requested declaration, information or documents.

Forms / Online services

Who to contact