Financial aid for energy efficiency renovation of a residential building without an energy performance assessment and limited to a single element (Klimabonus scheme 2026)
Last update
Important information: Continuation and partial reform of the 'Klimabonus Wunnen' financial aid scheme
You will be able to submit your application for the Klimabonus Wunnen 2026 financial aid scheme from 1 January 2026, the date on which the scheme is scheduled to take effect, with retroactive effect if the law has not been published before that date. However, because the law is still going through the legislative procedure, the processing and consideration of your application remain subject to the publication of the law in the Official Journal.
Summary:
You can apply for financial aid under the Klimabonus 2026 scheme subject to certain conditions.
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. These 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.
Financial aid for sustainable energy efficiency renovation projects may be received concurrently with aid available for the implementation of technical installations.
This Klimabonus aid can only be granted once and only for a residential building located in Luxembourg.
Who is concerned
Applicants concerned
Anyone 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:
- the legal representative of a group of natural or legal persons, provided that you are a part of this group yourself;
- the 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 monitored 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.
No aid will be allocated for the surfaces of elements renovated with fossil-based insulation material, except for ground-supported walls, green roofs, green walls and floor slabs in contact with the ground. This provision does not apply to fossil-based insulation material made from more than 50% recycled materials. 'Fossil-based' (synthetic insulation) insulation materials for which more than 50% of the raw materials come from biomass are eligible under the category 'other materials'.
If the attic space is heated, the renovation of the roofing must be combined with the replacement of the roof windows if these windows are more than 10 years old and do not have a heat transfer coefficient lower than or equal to 1.40 W/m2K.
To prevent humidity due to condensation, and the ensuing problems (mould, etc.), the renovation of the windows may be subsidised, provided that:
- the external wall or the roof of the heated attic space has a heat transfer coefficient lower than or equal to 0.85 W/m2K; or
- the building has a controlled mechanical ventilation system.
Requirements for enhanced construction elements
| Performance standard III | Performance standard II *** | Performance standard I *** | |
|---|---|---|---|
| Minimum thickness of insulation in cm | Maximum value of U (W/m2K) | Maximum value of U (W/m2K) | |
| External wall (external insulation) | 15 | 0.17 | 0.13 |
| External wall (internal insulation) or insulation of the internal side combined with insulation of the external side***** | 8 * | 10 cm * | 12 cm * |
| Ground-supported wall or unheated zone | 12 | 0.22 | 0.17 |
| Pitched or flat roof **** | 20 | 0.13 | 0.11 |
| Ceiling slab against unheated zone | 20 | 0.13 | 0.10 |
| Floor slab against unheated zone or ground or exterior | 12 | 0.22 | 0.15 |
| Windows and French windows ** | Ug ≤ 0.6 W/(m2K) |
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 interior 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.
** Conditions for granting the aid:
- either guarantee a certain heat quality of the external wall based on the targeted performance standard (Uwall ≤ 0.85 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 attic space is heated, the renovation of the roof must include the replacement of the roof windows (if they are more than 10 years old, and if UW > 1.4 W/m2K) The new window must have a UW ≤ 1.4 W/m2K.
***** If both the interior and exterior sides are insulated, the insulation material applied on the exterior 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.
The minimum energy performance requirements also apply to residential buildings that are protected in the public interest, and are either fully or partially listed as national monuments.
Preliminary steps
For energy efficiency renovation projects that are limited to a single construction element of the thermal envelope, the works must be:
- either carried out by an approved business;
- or overseen by an energy consultant. The invoice for this consultancy service must be issued between 1 January 2026 and 31 December 2030 inclusive.
The amount of financial aid available for the energy consultant's assistance with the sustainable energy efficiency renovation project is:
- EUR 100 to check the conformity of the estimates given for the project;
- EUR 400 for on-site verification of the compliance of the works.
Prior to commencing the energy efficiency renovation works, you must obtain an agreement in principle from the Single point of contact for housing assistance (Guichet unique des aides au logement), established on the basis of an energy consultant's report.
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 no later than 4 years after 31 December of the calendar year to which the invoice pertains.
The invoices for the energy efficiency renovation works must be issued between 1 January 2026 and 31 December 2035 inclusive.
The first application for an agreement in principle must be submitted between 1 January 2026 and 31 December 2030 inclusive.
Applications for financial aid for liquidation must be submitted no later than 31 December 2039.
How to proceed
You must file your application 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
- After the works: request for payment of the aid
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 the MyGuichet.lu mobile application (see 'Online services and forms' below). This is a procedure with authentication that requires:
- a LuxTrust product; or
- an electronic identity card (eID);
- or by post (preferably by registered mail), or by handing in the dedicated form (see 'Online services and forms') at the Single point of contact for housing assistance (Guichet unique des aides au logement):
- if you are a natural person: the DEPA-2026 aid application form for natural persons; or
- if you represent a legal person: the DEPA-2026 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.
Once the energy efficiency renovation measure has been completed, you can apply for the payment of the financial aid for energy efficiency renovation. 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-2026) that is specific to the refurbished element. This form is provided by the approved business or energy consultant. This form must be accompanied by supporting documents.
Supporting documents
- Application for the agreement in principle
- Application for payment of financial aid
To apply for the agreement in principle, in addition to the DEPA-2026 financial aid application form (natural or legal person), you must 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:
- the appendix form COLL-2026 and a power of attorney for each owner PROC-2026. Alternatively, a report drawn up by the commonhold association during a general meeting authorising the renovation works;
- 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-2026), applicants must provide:
- if you are a private individual: the DEPA-2026 aid application form for natural persons;
- if you represent a legal person: the DEPA-2026 financial aid application form for legal persons;
- where applicable, the form reporting any change of address or bank account details;
- a bank account identification document (RIB) for the account indicated in the application form;
- 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 this estimate 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 pertains to a commonhold or multi-unit residence (if any amendments have been made to the first application):
- the appendix form COLL-2026 and a power of attorney for each owner PROC-2026. Alternatively, a report drawn up by the commonhold association during a general meeting authorising the renovation works;
- 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.
| Refurbished construction element of the thermal envelope | Category of insulation material | Performance standard III | Performance standard II | Performance standard I |
|---|---|---|---|---|
| Element in contact with the exterior: external wall (insulated on the exterior side, on the interior side in combination with insulation on the exterior side, or insulated only on the interior side***), pitched or flat roof, floor slab in contact with the exterior | a. fossil-based (minimum 50% recycled*) and other materials** | 35 | 45 | 60 |
| b. mineral | 60 | 70 | 85 | |
| c. eco-friendly | 90 | 100 | 115 | |
| External wall (insulated on the exterior side) with cladding**** | c. eco-friendly | 105 | 115 | 130 |
| Element in contact with an unheated zone or the ground: ceiling slab in contact with an unheated zone, wall or floor slab in contact with the ground or an unheated zone | a. fossil-based (minimum 50% recycled*) and other materials** | 20 | 30 | 45 |
| b. mineral | 25 | 35 | 50 | |
| c. eco-friendly | 40 | 50 | 65 | |
| Windows and French windows | 70 |
*recycled fossil-based insulation material required except for walls in contact with the ground, green roofs, green walls and floor slabs in contact with the ground;
**other materials: * materials that do not fall under the definitions of categories (b) and (c) and that are not fossil based;
***for insulation that is only on the interior side, the specific financial aid [euros/m2 renovated] listed in the table above is reduced by 25%;
***eco-friendly insulation material and cladding must be attached mechanically; cladding that contains fossil-based materials is not permitted.
The requirement of mechanical attachment for category (c) eco-friendly insulation materials does not apply to walls insulated from the inside or outside.
Aid mark-up for the use of recycled materials for mineral insulation material
If mineral 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.
Aid mark-up for installing a green external wall or a green roof
If the renovation project involves installing a green external wall or a green roof, 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 are acting 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.
Online services and forms
Online services
Downloadable forms
Note: view tips for using PDF forms.
Applications and attachments (to be filled in by the applicant)
Certificates of conformity (to be filled in by the professionals)
Change of address and/or bank account
Who to contact
Klima-Agence
- Address:
- 2, circuit de la Foire Internationale L-1347 Luxembourg Luxembourg
- Phone:
- (+352) 8002 11 90
- Email address:
- info@klima-agence.lu
- Website:
- http://www.klima-agence.lu
Ministry of Housing and Spatial Planning Single point of contact for housing assistance
- Address:
- 11, rue de Hollerich L-1741 Luxembourg Luxembourg
- Phone:
-
(+352) 80 02 10 10
Monday to Friday from 8.00 to 16.00
- Fax:
- (+352) 45 88 44
- Email address:
- info@ml.etat.lu
- Website:
- http://www.logement.lu
Closed ⋅ Opens Monday at 8.00
- Friday:
- 8.00 to 12.00 , 13.30 to 16.00
- Saturday:
- Closed
- Sunday:
- Closed
- Monday:
- 8.00 to 12.00 , 13.30 to 16.00
- Tuesday:
- 8.00 to 12.00 , 13.30 to 16.00
- Wednesday:
- 8.00 to 12.00 , 13.30 to 16.00
- Thursday:
- Closed
Related procedures and links
Procedures
Links
Legal references
-
Commission Regulation (EU) 2023/2831 of 13 December 2023
on the application of Articles 107 and 108 of the Treaty on the Functioning of the European Union to de minimis aid
-
Projet de loi 8585
instituant un régime d’aides pour la promotion de la durabilité, de l’utilisation rationnelle de l’énergie et des énergies renouvelables dans le domaine du logement
