Klimabonus: Luxembourg's Renovation & Energy Subsidies (2026)

Buying an older house in Luxembourg usually means inheriting single glazing, thin walls and a fossil boiler. The state's answer is Klimabonus, a subsidy programme that, stacked with communal top-ups, supplier premiums and 3% VAT, can cover half or more of the energy-related cost of a renovation. The updated 2026 scheme, in force since 1 January, simplified the paperwork and moved several aids to flat rates. Here's how to use it without tripping over the rules.

What Klimabonus pays for

The headline 2026 rates (always confirm your exact case in the Klima-Agence subsidy simulator before signing quotes):

Since 2026, fossil-origin insulants are only subsidised if they contain more than 50 % recycled content. Biosourced materials (wood fibre, cellulose, cork) earn the top rates. Overall, Klimabonus alone can reimburse 50–62.5% of eligible pre-VAT costs. Fossil boilers get nothing: gas and oil replacements have been out of the scheme for years, in line with EU guidance ending subsidies for stand-alone fossil boilers.

Start with the free advice, then get approval

Klima-Agence runs a free, neutral advice service (klima-agence.lu, hotline 8002 11 90) that will sketch your renovation strategy at no cost. For multi-measure renovations you'll then need an accredited energy advisor (conseiller énergétique agréé, the "Energieberoder") to draw up the technical file.

The critical procedural point in the 2026 scheme: obtain the agreement in principle before works begin. You file the application via MyGuichet.lu to the housing-aids single desk and wait for the green light; works started earlier are simply ineligible. After completion, you submit invoices for payment; you currently have up to 4 years from the invoice date to file the final claim. Use certified installers for technical systems; a bargain quote from a non-accredited firm can cost you the entire subsidy.

Stack the top-ups

• Communal aids: many communes add 10–50% on top of the state amount. Check your commune's website before finalising the budget.
• enoprimes: premiums funded by energy suppliers under the energy-efficiency obligation. Crucial detail: the enoprimes request must be lodged before you accept the contractor's quote.
• 3% VAT: renovation works on a dwelling over 20 years old, used as a main residence and carried out by professionals, qualify for the super-reduced 3% rate instead of 17%, a benefit capped at €50,000 per dwelling, applied directly on invoices after AED approval.
• Climate loans: zero- or low-interest climate loan options exist for households financing deep renovations.

The boiler question in 2026

Luxembourg has no outright ban on fossil boilers: the phase-out is driven by incentives instead. The CO₂ tax has climbed to €45/tonne in 2026, pushing up heating-oil and gas bills each year, and replacement subsidies flow exclusively toward heat pumps, wood heating and district heat. Practically: if your new house has a 20-year-old oil burner, plan its replacement now, while the subsidy environment is at its most generous.

What the numbers look like

Take a 1970s house bought with an oil boiler and uninsulated walls. Roof and façade insulation plus a heat pump might cost ~€80,000 gross. Klimabonus flat rates and per-m² aids, a typical communal top-up, enoprimes and the 3% VAT can realistically bring the net outlay down toward €40,000–50,000, while cutting energy bills by €2,000–3,000 a year at current prices, a payback inside 15–20 years, before counting the resale premium of a better energy class.

Common mistakes

1. Starting works before the agreement in principle: the single most expensive error; there is no retroactive fix.
2. Accepting quotes before filing for enoprimes.
3. Using non-accredited installers for heat pumps or PV.
4. Forgetting the communal aid entirely.
5. Insulating to the minimum standard when a slightly thicker spec jumps you a subsidy tier.