Klimabonus and PrimeHouse: Luxembourg heating subsidies explained (2026 guide)

Replacing a gas or oil boiler with a heat pump, adding solar thermal, or upgrading to a modern condensing system? Luxembourg has generous subsidy schemes that can cover 25–60% of the equipment cost. This guide explains Klimabonus, PrimeHouse, and how to combine them in 2026.

The two main schemes

Klimabonus — national climate subsidy

Klimabonus is Luxembourg’s central climate-transition incentive program. It funds heating system upgrades, renewable energy installations, and efficient appliances. Eligible works include:

• Heat pump installation (air-water, ground-source, air-air)
• Pellet / wood boiler
• Solar thermal (for DHW or combined heating)
• Solar PV (for domestic consumption)
• Deep retrofit insulation
• Ventilation with heat recovery (VMC double flux)
• Electric charging stations (borne de recharge)

Managed by the Ministry of the Environment and the Energy Agency. Funding typically covers 25–50% of eligible costs, with a cap per category.

PrimeHouse — municipal top-ups

Many Luxembourg communes run their own heating/insulation subsidy on top of Klimabonus. The program name varies (PrimeHouse, Prime commune) but all follow a similar logic: cumulative with national subsidies, usually 5–20% additional.

Examples:

• Luxembourg-Ville — various subsidies for thermal renovation
• Esch-sur-Alzette — matches a share of Klimabonus for certain works
• Differdange — multi-family building incentives

Check your commune’s website or their Guichet Unique.

Typical Klimabonus amounts (2026 reference)

Rates update periodically — always check the latest at klima-agence.lu before committing:

• Air-water heat pump: up to on request 000–on request 000 per unit
• Ground-source heat pump: up to on request 000–on request 000 (higher due to borehole cost)
• Solar thermal DHW: up to on request 500–on request 500
• Pellet boiler: up to on request 000–on request 500
• Condensing gas boiler upgrade: limited or phased out in 2026 — national policy moving away from fossil heating subsidies
• EV charging station at home: up to on request 000–on request 500

Amounts depend on whether the property is a primary residence, the technology selected, and the efficiency of the equipment (better SCOP/COP = higher subsidy).

Who can apply

• Primary residence owners: full subsidies available
• Secondary residence owners: reduced rates or excluded depending on the measure
• Landlords renting out property: eligible but with specific conditions (tenant cannot double-apply)
• Commercial buildings: separate track with different rules (not covered here)

You must be the property owner or have authorization from the owner. Renters cannot apply directly.

How to apply — the typical process

1. Get quotes from certified installers

The installer must be certified for the category of work. For heat pumps, the F-Gaz certification is required. For boilers, the entreprise agréée status is needed. Ask for the certificate before signing.

2. Energy audit if required

Some subsidies require a pre-works energy audit by a certified auditor (conseiller en énergie). Cost: on request. The audit itself is sometimes subsidized.

3. Pre-application (for larger projects)

For high-value works (over on request 000), pre-register the project with the Klimabonus administration BEFORE starting. Failing to do so can reduce or cancel the eligibility.

4. Have the work done

Retain all documentation: quotes, invoices, equipment specifications (power, efficiency, model numbers), photos of installation, commissioning certificate.

5. Submit the application

Online via MyGuichet.lu or paper submission to the Klimabonus office. You’ll need:

• Property ownership proof
• Pre-works and post-works photos
• Itemized invoices
• Installer certification
• Technical specifications of the equipment
• Energy audit if applicable

6. Wait for review and payment

Review takes 3–6 months typically. Payment is made directly to the applicant’s bank account. Smaller subsidies clear faster than large ones.

Stacking rules — combining subsidies

In principle, Klimabonus + commune subsidy + tax deductions can stack, but each scheme caps the combined aid at a percentage of total eligible cost (typically 50–70%). Over-claiming triggers clawback.

Commercial bank prêt climatique loans (0% or low-rate, up to on request 000) can also fund the remaining cost — not technically a subsidy, but effectively free capital for the works.

Traps to avoid

• Starting works before pre-approval on subsidies that require pre-application
• Using an uncertified installer — subsidy rejected, no recourse
• Missing the application deadline (typically within 12 months of invoice)
• Incomplete technical file — especially missing equipment certifications (Eurovent, NF PAC)
• Equipment not meeting minimum efficiency thresholds — some cheap heat pumps don’t qualify

Frequently asked questions

I’m planning to move out in 2 years — is a heat pump still worth it?

A heat pump adds meaningful property value in Luxembourg (typically on request 000–on request 000 on resale for a well-installed unit). With Klimabonus covering half the cost, the ROI is generally positive even on short ownership periods.

Can I get subsidies for replacing a gas boiler with a new gas boiler?

As of 2026, new gas boiler installations are largely excluded from Klimabonus, except for specific edge cases (condensing + solar hybrid). Luxembourg’s policy direction is clear — fossil heating will not be subsidized going forward.

Are there subsidies for tenants?

Not directly. Tenants can ask their landlord to apply and pass on the benefit via reduced rent or improved living conditions. Some communes have small tenant grants for energy-efficient behavior changes (thermostats, appliances) but the amounts are modest.

Where do I get official current amounts?

klima-agence.lu is the central authority. Their helpline (in French/German/English) is excellent for case-specific questions.

Need help with your Luxembourg plumbing?

Weber & Fils has English-speaking technicians for bookings, emergency call-outs, and quotes: weberetfils.lu/en or call +352 20 60 22 22 — 24/7.