Klimabonus insulation and windows: one renovation measure
Grants for owners improving one wall, roof, floor or window element of an older Luxembourg home, without a full energy performance assessment.
Ta możliwość jest obecnie dostępna po angielsku.
This simplified route funds a renovation limited to one construction element that separates heated rooms from outdoors, the ground or an unheated space. It covers roof, wall and floor insulation or replacement windows and French windows (glazed doors). An approved business must carry out the work, or an approved energy consultant must monitor it. The aid can be granted only once for the residential building. It can be combined with aid for renewable-energy technical installations.
The grant equals the renovated area multiplied by the applicable euro-per-square-metre rate. The three performance standards reward different insulation levels. Rates in brackets apply only when the approval-in-principle application is submitted from 1 January 2026 to 30 June 2027 and the invoice is issued by 31 December 2030.
| Renovated element and insulation category | Standard III, €/m² | Standard II, €/m² | Standard I, €/m² |
|---|---|---|---|
| External wall, roof or floor against outdoors: eligible recycled fossil-based or other materials | 35 (40) | 45 (50) | 60 (70) |
| Same elements: mineral insulation | 60 (70) | 70 (80) | 85 (100) |
| Same elements: eco-friendly insulation | 90 (105) | 100 (120) | 115 (140) |
| External wall insulated outside, with eco-friendly insulation and cladding | 105 (125) | 115 (140) | 130 (155) |
| Ceiling, wall or floor against an unheated space or the ground: eligible recycled fossil-based or other materials | 20 (25) | 30 (35) | 45 (50) |
| Same elements: mineral insulation | 25 (30) | 35 (40) | 50 (60) |
| Same elements: eco-friendly insulation | 40 (50) | 50 (60) | 65 (75) |
| Windows and French windows | 70 (80) | 70 (80) | 70 (80) |
These are base rates. An external wall insulated only on the inside receives 25% less than the applicable rate. “Other materials” excludes mineral, eco-friendly and fossil-based insulation; synthetic insulation with more than 50% biomass raw materials qualifies in that category. Eco-friendly insulation and cladding must be mechanically attached, and cladding containing fossil-based materials is excluded. The mechanical-attachment requirement for eco-friendly insulation does not apply to walls insulated inside or outside.
A €15 mark-up on the base subsidy is available for mineral insulation made from more than 50% recycled materials, eco-friendly insulation sourced from certified sustainable crops, or a green external wall or roof. Occasional energy-consultant assistance can receive €100 for checking quotations and €400 for checking the completed work on site; that consultancy invoice must be issued from 1 January 2026 to 31 December 2030.
The standard procedure pays the aid into your bank account after the work. From 1 January 2027, insulation works with invoices issued on or after that date can instead use optional pre-financing: a registered intermediary company applies through MyGuichet.lu, receives the State aid and deducts the full amount from your invoice. A registered energy adviser or registered tradesperson must submit the approval-in-principle application before work starts, and approval must be obtained before starting. Each renovation project needs a separate application and invoice. Commercial-company investments are excluded from pre-financing, as are renovation works where the aid plus your deposit exceeds the final price excluding VAT.
Eligibility
- The home must be in Luxembourg and older than 10 years from the building-permit issue date when you apply for aid. Individuals, private-law legal entities and public legal entities other than the State can apply as owners. A group representative must also belong to the group. After a change of ownership, the previous owner who invested may receive the aid if the new owner gives up their entitlement in that person's favour.
- A legal entity carrying out an economic activity receives aid under EU Regulation 2023/2831 on de minimis aid: this grant counts towards the business's cumulative limit for aid awarded under the de minimis rules. Indicate whether the aid is registered to the applicant business or transferred to someone else; a transfer requires formal signed or notarised proof and identification of the final recipient.
- Use a business approved under the law of 21 April 1993, or have an approved energy consultant occasionally monitor the work. Obtain approval in principle before starting. The element must meet the technical table below, including minimum standard III thickness for standards II and I. The same minimum requirements apply to protected or listed residential buildings.
| Element | Standard III minimum thickness | Standard II requirement | Standard I requirement |
|---|---|---|---|
| External wall insulated outside | 15 cm | U ≤ 0.17 W/(m²K) | U ≤ 0.13 W/(m²K) |
| External wall insulated inside, or inside and outside together | 8 cm | At least 10 cm insulation | At least 12 cm insulation |
| Wall against ground or an unheated space | 12 cm | U ≤ 0.22 W/(m²K) | U ≤ 0.17 W/(m²K) |
| Pitched or flat roof | 20 cm | U ≤ 0.13 W/(m²K) | U ≤ 0.11 W/(m²K) |
| Ceiling against an unheated space | 20 cm | U ≤ 0.13 W/(m²K) | U ≤ 0.10 W/(m²K) |
| Floor against an unheated space, ground or outdoors | 12 cm | U ≤ 0.22 W/(m²K) | U ≤ 0.15 W/(m²K) |
| Windows and French windows | Glazing Ug ≤ 0.6 W/(m²K) | Glazing Ug ≤ 0.6 W/(m²K) | Glazing Ug ≤ 0.6 W/(m²K) |
U measures heat passing through an element; lower values mean less heat loss. Ug applies to the glazing, while Uw below applies to the whole window. Thicknesses assume insulation conductivity of 0.035 W/(mK), except internal wall insulation, which assumes 0.040 W/(mK). Convert the required thickness for the actual material conductivity. Where the wall is insulated on both sides, the outside insulation must have thermal resistance R of at least 2 (m²K)/W.
- Fossil-based insulation is excluded except for walls and floor slabs against the ground, green roofs and green walls, or insulation with more than 50% recycled content. Synthetic insulation with more than 50% biomass raw materials is eligible as “other materials”.
- For a heated attic, roof renovation must include replacing roof windows that are more than 10 years old and have Uw above 1.4 W/(m²K). New roof windows must have Uw ≤ 1.4 W/(m²K).
- Window grants require the external wall or roof of the heated attic to have U ≤ 0.85 W/(m²K), or the building must have controlled mechanical ventilation, which removes humid air to prevent condensation and mould.
How to apply
- Status
- zamyka się 31 gru 2030
- Otwiera się
- Zamyka się
- Warunki naboru
- Submit the first approval-in-principle application during this period and obtain approval before work starts.[^c4][^c5]
- The higher bracketed rates require approval application by 30 June 2027 and an invoice by 31 December 2030.[^c6]
Before work, apply to the Single point of contact for housing assistance (Guichet unique des aides au logement) for approval in principle. Use MyGuichet.lu with LuxTrust or an electronic identity card, or submit the DEPA-2026 form for individuals or legal entities by post or in person. The approved business or monitoring consultant signs the DESC description of the proposed measure and confirms the quotation. Supply proof of the building's age and, for an extension, the plans after renovation. Start work only after approval. If the business or consultant advises a change to the renovation plan, you can request a new approval.
After completion, submit the DEPA-2026 application and the element-specific CONF-2026 confirmation supplied by your approved business or consultant, with bank details, eligible-cost invoices and payment proof. A consultant's monitoring invoice must include the on-site compliance check. For shared or multi-unit property, provide owner authorisations or the association's decision, and a list of flats with their energy-reference areas excluding common areas; provide updated shared-property documents for payment if they changed.
Renovation invoices must be issued from 1 January 2026 to 31 December 2035. Apply for payment after completion and within four years after 31 December of the invoice year, with an absolute final deadline of 31 December 2039. A group representative receiving the payment must immediately pass each member's share to them and send copies of the transfers to the housing-assistance office. Aid may be recovered for inaccurate or incomplete statements, or failure to provide requested information or documents.