The Environment Agency (Administration de l’environnement) grants subsidies for energy efficiency renovation projects undertaken to:

• improve the long-term sustainability of a residential building;
• implement technical installations making use of renewable energy sources.

The Klimabonus scheme applies to the sustainable energy efficiency renovation 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.

Who is concerned

Applicants concerned

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

• natural person;
• legal persons established under private law;
• public legal persons 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;
• centralised or decentralised controlled ventilation systems.

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.

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 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.
• if a controlled ventilation system with heat recovery is being installed:
  • the yield of the heat recovery system ('Wärmebereitstellungsgrad') must be greater than or equal to 80 %;
  • the absorbed electrical power may not exceed 0.40 W/(m³/h);
  • the building must be airtight (n₅₀ = 2.0 1/hour), ascertained by an airtightness test;
  • at least 90% of the energy reference area must be mechanically ventilated.

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 window (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 install 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.

Preliminary steps

Energy performance assessment

In order to receive the Klimabonus aid for the sustainable energy renovation of an existing building, you must first have an energy performance assessment carried out and obtain the related report. The assessment and report must be produced by an approved energy consultant to ensure that the energy efficiency renovation project is adequate before the works begin.

The invoice for this consultancy service must be issued between 1 January 2022 and 31 December 2025 inclusive.

The report drawn up in connection with the energy assessment contains recommendations on how to improve the building's energy performance. A subsidy may also be granted for this consultancy service.

Financial aid for an energy assessment by an approved energy consultant

The amount of financial aid granted for a sustainable energy renovation project is:

• EUR 1,500 for a single-family residence (a house);
• EUR 1,800 for a residence comprising 2 flats. A EUR 50 supplement is added to this base amount for each additional flat. The total amount of aid is limited to EUR 2,600.

The amount of the financial aid can never exceed the actual cost of the energy consultation.

If the energy consultation took place in connection with a sustainable energy renovation project, the financial aid may be increased by EUR 140 (maximum EUR 700) for the calculation of a thermal bridge and proposals for related treatments if:

• the renovation works were implemented;
• the heating energy expenditure index of the building, after the works, reaches at least efficiency class C.

The energy consultation must be supplemented by specific assistance by the energy consultant, which can be covered by financial aid in the case of:

• measures taken to confirm the conformity of estimates proposed for the works (EUR 75 per measure, capped at EUR 300);
• measures taken to confirm the conformity of the works on site (EUR 200 per measure, capped at EUR 800).

Payment of the 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.

Deadlines

Applications for subsidies must be filed after the completion of the works within 4 years as of 31 December of the calendar year that the invoice apply to.

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.

The energy efficiency renovation works must have been carried out on the basis of an energy efficiency report that is invoiced from 1 January 2022 up to and including 31 December 2025.

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, established on the basis of an energy consultant's report.

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 financial 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.

Note: If, based on the advice of the energy consultant, 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 work has been 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 'Confirmation of energy efficiency renovation of an existing residential building' (Confirmation rénovation énergétique d’un logement existant – CONF-2022) that has been provided by the approved 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 entitled 'Energy efficiency renovation concept' (Concept d’assainissement énergétique - COAS_2022), specifying all of the projected energy efficiency renovation measures subject to the agreement in principle. It must be completed and signed by the approved energy consultant;
• upon the AEV's request, the concluding report prepared by the energy consultant, including the overall inventory and the entire energy efficiency renovation concept;
• a copy of the initial building permit for the building or an official document certifying the age of the building;
• the energy performance certificate (certificat de performance énergétique – CPE) of the building before the renovation works;
• if a controlled mechanical ventilation system is being installed, construction plans that:
  • correspond to the situation after the energy efficiency renovation works; and
  • illustrate the energy reference area and the mechanically ventilated portion of this area;
• 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;
• an estimate of the energy consultant's fees or a confirmed estimate per projected measure.
• 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 invoices for the energy consultation must be detailed as follows:
  • the energy consultation provided;
  • confirmation of the conformity of the estimates;
  • confirmation of the conformity of the on-site works;
  • any thermal bridge calculations, if applicable;
• the final report prepared by the energy consultant upon confirmation of the compliance of the offers and the on-site works;
• the energy performance certificate (certificat de performance énergétique – CPE) of the building after the renovation works;
• if a controlled mechanical ventilation system with heat recovery is installed, the duly signed airtightness assessment reports and certificate.
• 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.

Energy bonus

If the building meets thermal insulation classes C, B or A after renovation, the amount of the subsidy granted for the individual measures implemented on the thermal envelope may be increased, on condition that the thermal insulation class has improved by at least two classes.

To obtain the bonus, the insulation measures may also be implemented in stages.

Proof of eligibility for the bonus must be demonstrated by producing the energy performance certificates before and after the energy efficiency renovation works.

Measures implemented and subsidised under the former PRIMe House aid scheme may be taken into account to demonstrate the improvement by at least 2 classes, which is required for eligibility for the aid bonus.

Controlled mechanical ventilation system

The financial aid is calculated based on the energy reference area shown on the building's energy performance certificate.

The energy reference area is multiplied by the corresponding amount shown in the table below.

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.

Good to know

Some communes grant aid to supplement State aid for energy savings and renewable energies. For more information, please contact the commune of residence or Klima-Agence.

Forms / Online services

Who to contact