Klimabonus 2026 amounts by type of works

The Klimabonus Wunnen 2026 pays a flat rate per m² or per installation, set by the law of 24 July 2026. The figure in brackets is the increased amount, which applies if the approval in principle is requested (or the heat pump ordered) between 1 January 2026 and 30 June 2027. The grant is managed by the Environment Administration (AEV).

Thermal insulation (€ per m² of insulated area)

Standard III is the minimum requirement (for example 15 cm of insulation with a conductivity of 0.035 for an externally insulated wall, 20 cm on the roof and the attic floor, 12 cm under a cellar slab); standard I is the most efficient (U ≤ 0.13 W/m²K for an external wall).

What increases or reduces the insulation grant

• Internal insulation only: −25% (€115/m² becomes €86.25/m²). Combined internal and external insulation is not reduced if the external layer reaches a thermal resistance R ≥ 2.
• +€15/m² for mineral insulation with over 50% recycled content, ecological insulation from certified sources (FSC, PEFC, natureplus…) or a green roof or façade.
• Class bonus: +20% if the thermal insulation class reaches C, +30% for B, +50% for A or A+, provided you gain at least two classes, proven by an energy performance certificate (CPE/Energiepass) before and after the works. The bonus can be earned in stages.
• Fossil insulation (EPS or XPS polystyrene, polyurethane): no grant unless it contains over 50% recycled material, except for walls and slabs against the ground and green roofs or walls.
• Cap: including increases and bonuses, insulation is never subsidised beyond 60% of the cost excluding VAT.

Windows and ventilation

Heating, solar and technical installations (single-family house)

In apartment buildings, amounts are set per dwelling with a cap per building (air-to-water heat pump: €8,000 per dwelling, €10,000 increased). A new oil or gas boiler receives no grant at all. Detailed technical conditions are on our pages on heat pump grants and solar panel grants. All collective rates and the managing agent’s role: rates and procedure for co-ownerships.

What changed in 2026 compared with the 2022 scheme

Since 1 January 2026 the Klimabonus no longer refunds a percentage of the works: it pays flat rates that are higher than the old scale. The law of 24 July 2026 (parliamentary bill 8585), published in the Official Journal, applies retroactively to every invoice since that date.

• Removed: the « boiler at least 10 years old » condition, grants for wood-chip and log boilers, solar thermal and wood heating in new builds, the separate 25% insulation bonus (now built into the flat rates).
• New: the « non-fossil cladding » rate, a green-roof/façade bonus, the HEMS grant, payment of the advice grant as soon as the approval in principle is requested, and pre-financing for heat pumps and insulation on invoices from 1 January 2027.
• Transition: energy advice invoiced and applied for before 31 December 2025 stays under the old scheme; a PV system ordered between 2023 and 4 March 2026 keeps its old-scheme options for an invoice dated no later than 31 December 2026.

Three worked examples: what an owner actually receives

These three cases use the 2026 scale and market prices collected in September 2026. Each time, the grant retained is the lower of the flat rate and the cap.

Example 3 — Envelope renovation with class bonus

1975 house, 140 m², insulation class F raised to B (a four-class gain, hence +30%), approval in principle requested in November 2026.

On the roof, the high flat rate is clipped by the 60% cap; it is on the mineral façade, more expensive per m², that the class bonus really pays. The 3% VAT rate instead of 17% saves a further €8,239 on these works.

Who can receive the Klimabonus, and on what conditions

Any owner of a home in Luxembourg can apply for the Klimabonus, whether they live in it or rent it out, provided the building is more than 10 years old for insulation, windows and ventilation.

• Beneficiaries: private individuals and private or public legal entities (except the State). There is no main-residence condition: landlords are eligible.
• Building age: more than 10 years since the first building permit was issued; the permit date or a municipal certificate is the proof.
• One grant per element of the building, and only one grant between heat pump, wood boiler and heat network per house or building.
• Who does the work: for a single element, an approved company (law of 21 April 1993) or an energy advisor supervising the site; for more than one element or with ventilation, energy advice with a report before the works.
• Documents: energy performance certificate before the works (with the approval request) and after the works (with the payment request), first building permit, checked quotes, photos; airtightness test for ventilation. The certificate itself is not subsidised.
• Caps: 60% of the cost excl. VAT for insulation; for technical installations, the grant cannot exceed the invoice excluding VAT (a 50% cap applies only to stoves, particle filters, adapting the heat distribution and heat networks).
• Co-ownership: collective file (forms COLL-2026 and PROC-2026); energy renovation of common parts is voted by a majority of the votes of all co-owners.

Procedure: the order that decides the grant

For insulation, windows and ventilation, the approval in principle must be requested before the works start; for a heat pump, solar panels or a pellet boiler, the application is made after installation.

Applications are filed on MyGuichet.lu or at the Guichet unique des aides au logement (11, rue de Hollerich, Luxembourg, tel. 80 02 10 10). Klima-Agence answers free of charge on 8002 11 90. The document-by-document timeline is in our guide to the energy renovation steps in Luxembourg.

Energy advice: mandatory beyond one element, subsidised up to €2,000

Advice from an approved energy advisor is mandatory as soon as your renovation covers more than one element or includes ventilation; the State funds it with €1,700 for a house, or €2,000 if the approval in principle is requested before 30 June 2027.

The grant never exceeds the real cost of the advice. It is cut by 50% if the building was already subsidised under the 2017 or 2022 schemes, and by 70% if the advice only covers a technical installation. Klima-Agence’s free basic advice does not replace the approved advisor. Role, fees and how to choose: see our page on energy advisors in Luxembourg.

Pre-financing: when the grant is deducted from the invoice

For photovoltaics, a registered installer can already deduct the Klimabonus from your invoice; for heat pumps and insulation, pre-financing only applies to invoices issued from 1 January 2027.

• Photovoltaics (and a battery bought with it): grant deducted from the price including VAT, deposit limited to 30%, decision within 15 working days (silence means approval), installer paid within 15 working days. Not available for a battery added on its own or for leasing. See solar panel pre-financing.
• Heat pumps and insulation (invoices from 2027): the company listed in the AEV register deducts the grant from the price excluding VAT. For insulation, one application and one invoice per measure, and the prior approval in principle is still required. Excluded if grant plus deposit exceed the price excluding VAT.
• Same amount: pre-financing is optional and does not change the grant.

3% VAT: the saving that applies to the whole invoice

The Klimabonus can be combined with the super-reduced VAT rate of 3% instead of 17%, which applies to renovating a home at least 10 years old used as a main residence, up to €50,000 of tax advantage per dwelling.

• A home let to a tenant who lives there as a main residence is eligible for renovation works.
• For direct 3% invoicing, the company requests the AED approval before the works and you countersign it; otherwise you pay 17% and claim a refund.
• Installed solar panels are invoiced at 3% directly, outside the cap; air conditioning is excluded.
• Raising the cap to €100,000 has been announced but is not in force: the cap remains €50,000.

Form, list of invoices and refunds: our guide to 3% VAT for renovation.

Klimaprêt: the State pays 1.5% interest on your loan

The Klimaprêt is not a zero-rate loan: it is an ordinary bank loan on which the State covers 1.5% interest a year, on up to €100,000 over up to 15 years, never more than 10% of the capital and with no income condition.

Legal basis: amended law of 7 August 2023 on individual housing aid (articles 38 to 44). The former climate-loan law of 8 June 2022 has been repealed, and the zero-rate climate loan is no longer available for new applications.

Social Topup: 10% to 100% of the Klimabonus on top for lower incomes

Owners on lower incomes can receive, on top of the Klimabonus, a Housing Ministry grant worth 10% to 100% of the grant awarded, depending on income and household size: it is not an automatic doubling.

Conditions: adult owner, no more than one third of another home, home over 10 years old used as main residence for at least 2 years, application (form F3) within 2 years of the Klimabonus being granted, capital grants capped at €35,000.

Timeline 2026-2039: the dates that change the amount

Two dates matter more than the others: 30 June 2027, when the increase ends, and 31 December of the fourth year after your invoice, when your right to the grant expires.

Municipalities and energy suppliers: extras to check

Almost all municipalities and some energy suppliers add their own grants to the Klimabonus, but amounts and rules differ from one municipality and supplier to the next. On the municipal side, 98 of the 100 communes top up the Klimabonus, most often by 10% to 50% of the state grant: find your commune’s amount in the table of all 100 communes. Ask your municipal administration and your supplier (the Enoprimes programme, for example) before signing, as their filing rules are their own; Klima-Agence’s free advice service can point you in the right direction. Businesses and commercial premises: see energy renovation grants for SMEs.

Six mistakes that cost you all or part of the grant

• Starting insulation, windows or ventilation before requesting the approval in principle: have the quote state that works only start once it has been filed.
• Forgetting the « before » energy certificate: incomplete file, and the class bonus (up to +50%) cannot be proven.
• Choosing non-recycled polystyrene or polyurethane on a façade or roof: €0/m².
• Installing heat-recovery ventilation without energy advice or an n50 ≤ 2.0 h⁻¹ test: no grant.
• Ordering the heat pump after 30 June 2027: €2,000 less.
• Missing the deadline of 4 years from 31 December of the invoice year.

Calculate your grants, then compare quotes

The energy renovation simulator calculates your 2026 grants from your surfaces, insulation materials and current heating. To move to the real thing, three companies established in Luxembourg send you a quote with the grant calculated item by item.

Frequently asked questions about renovation grants in Luxembourg