How much does energy renovation of a detached house in Luxembourg cost in 2026?
In Luxembourg, the majority of detached houses were built between the 1960s and 1990s — a period when thermal insulation was virtually non-existent and oil or gas heating was the norm. These homes now display EPC classes from E to I, placing them among the most energy-intensive properties in the Grand Duchy. Good news: in 2026, the revamped Klimabonus Wunnen scheme enables financing of up to 62.5% of costs for a comprehensive renovation, with subsidies that can exceed €50,000 for large-scale projects. This guide gives you everything you need to know: priority works for a detached house, real Luxembourg market prices, details of every available grant, the steps to follow in the right order, and mistakes to avoid.
State of Luxembourg’s detached house stock: why renovation is urgent
The 2021 population census (statistiques.public.lu) reveals that houses represent 45.9% of Luxembourg’s housing stock, but accommodate more than half of residents, as they are generally larger. More than 54% of homes in Luxembourg exceed 120 m² — a size that makes heating costs particularly heavy when insulation is failing.
Two factors explain the poor energy performance of many of these homes. First, the age of the housing stock: the majority of houses were built between the 1970s and 1990s, before any serious thermal regulations — insulation was absent or minimal, windows were single-glazed, and oil boilers were universal. Second, the strictness of the Luxembourg rating system: the Luxembourg EPC (Energy Performance Certificate), with classes from A+ to I, is significantly stricter than French or Belgian systems. A class D in France or Wallonia typically corresponds to a class F in Luxembourg — which explains why many apparently « decent » homes end up in class F, G, H or I according to the Luxembourg energy passport.
This observation is also an opportunity: because the starting point is often very low, the EPC class gains achievable with a well-executed renovation are considerable — and it is precisely this class improvement that the Klimabonus rewards. The more classes you improve, the higher the subsidy rates.
Luxembourg is studying a progressive ban on renting out the most energy-intensive properties. Class I is expected to be banned from rental from 2028, with other classes following progressively until 2035. If you own a property in class F to I, starting an energy renovation before 2028 is not only financially advantageous (grants in force until 2030–2035), but also legally preventive. These provisions are still at the draft legislation stage — verify legislative progress on guichet.lu before planning.
The 5 priority works for a detached house in Luxembourg
Effective energy renovation follows a precise logic: always start with the thermal envelope (insulation), then address the heating system, then ventilation. Doing the reverse — replacing the boiler before insulating — is a costly mistake, as a new high-performance heating system oversized for a poorly insulated building will consume far too much energy.
Roof insulation — the most cost-effective item
The roof accounts for 25 to 30% of heat losses in a poorly insulated home. It is the item offering the best return on investment, often recovered within 5 to 10 years. For unused loft spaces, applying 25 to 30 cm of blown insulation is the cheapest and fastest solution. For sloped roofs or flat roofs, techniques are more complex but Klimabonus grants are also higher. Roof insulation is also the measure that generates the largest EPC class gain: a gain of 2 to 3 classes is common when combining roof and heating.
Potential EPC gain: 1 to 3 classes depending on initial state | Heating bill savings: 25 to 30%
Heating system replacement — the strongest EPC impact
Replacing an old oil or gas boiler with an air-to-water or geothermal heat pump is the most impactful action on the EPC, as the score factors in the type of energy used: electricity from a heat pump weighs far less than oil or fossil gas in CO₂ emissions calculations. In Luxembourg, real installed prices for an air-to-water heat pump range from €16,000 to €24,000, and a geothermal heat pump from €30,000 to €40,000. The 2026 Klimabonus covers fixed amounts by type (see grants section). Essential condition: insulation must be sufficient for the heat pump to operate in the low temperature ranges (35°C) at which it is most efficient.
Potential EPC gain: 1 to 2 classes | Heating savings: 50 to 70% vs fossil boiler
External wall insulation — the most visible measure
Walls account for 20 to 25% of heat losses. External thermal insulation (ETI) is the most effective technique for a detached house: it eliminates thermal bridges, includes façade rendering, and does not reduce habitable space. For a typical Luxembourg semi-detached house, the ETI budget is between €20,000 and €35,000. For a four-façade house, between €50,000 and €70,000. The 2026 Klimabonus offers amounts from €60 to €115/m² depending on the chosen insulation material — ecological materials (wood fibre, cork, sheep’s wool) benefit from a significant premium. Internal wall insulation (IWI) is a cheaper alternative (30–40% less) but reduces habitable space and treats thermal bridges less effectively.
Potential EPC gain: 0.5 to 1 class | Heating savings: 20 to 25%
Window replacement — the cold’s point of entry
Windows and glazed openings account for 10 to 15% of heat losses, but above all are a direct source of discomfort (cold sensation near glass, condensation, draughts). Replacement with high-performance triple glazing (Uw ≤ 1.3 W/m²K, ideally < 0.8 W/m²K) significantly improves perceived comfort in winter. In Luxembourg, the price of a quality window installed ranges from €600 to €1,200 for triple-glazed PVC, and €900 to €1,800 for wood or aluminium. The 2026 Klimabonus offers a flat-rate grant of €70/m² of glazed area replaced. For a 10-window home: allow €8,000 to €15,000 supply and installation depending on dimensions and materials.
Potential EPC gain: 0.5 to 1 class | Comfort impact: very significant from the first winter
Dual-flow MVHR — essential in a well-insulated home
A well-insulated home is by nature more airtight. Without high-performance mechanical ventilation, this airtightness becomes a problem: humidity build-up, excessive CO₂, mould, material degradation. Dual-flow MVHR with heat recovery (85 to 95% efficiency) ensures continuous air renewal and recovers heat from extracted air before expelling it. It is an inseparable component of an ambitious comprehensive renovation targeting BBB or AAA classes. Installation costs between €6,000 and €18,000 depending on floor area and home configuration. It is eligible for Enoprimes (MVHR with heat recovery grant) and contributes to EPC improvement.
Potential EPC gain: contributes to overall BBB/AAA performance | Air quality impact: decisive
Installing a heat pump in an uninsulated home is like heating the outdoors. The heat pump will be oversized, consume a lot of electricity, and savings will be disappointing. The correct order is: (1) roof insulation, (2) wall insulation, (3) window replacement, (4) heating replacement, (5) dual-flow MVHR installation. If your budget does not allow everything at once, a Klima-Agence approved energy advisor will help you establish a phased works plan, prioritising the most cost-effective measures for your specific home.
Luxembourg market prices 2026 — item by item
The prices below are ranges for the Luxembourg 2026 market, VAT at 3% included (applicable for any home over 10 years old, primary residence). They include supply and installation by an approved tradesperson registered with the Luxembourg Chamber of Skilled Trades. Labour costs in the Grand Duchy are structurally higher than in France or Belgium (€65 to €95/hour for a specialist tradesperson), which explains the differences from neighbouring country rates.
| Work item | Price range incl. VAT (3%) | Indicative EPC gain | Klimabonus grant |
|---|---|---|---|
| Unused loft insulation (blown, 120 m²) | €4,000 – 8,000 | +1 to 2 classes | Up to €7,500 |
| Sloped roof insulation (sarking, 100 m²) | €15,000 – 25,000 | +1 to 3 classes | Up to €7,500 |
| External wall insulation (ETI) — semi-detached | €20,000 – 35,000 | +0.5 to 1 class | €56 – 115/m² |
| External wall insulation (ETI) — four-façade house | €50,000 – 70,000 | +0.5 to 1 class | €56 – 115/m² |
| Triple-glazed window replacement (10 windows, PVC) | €8,000 – 15,000 | +0.5 to 1 class | €70/m² glazed area |
| Air-to-water heat pump + emitters (low-temperature radiators or underfloor heating) | €16,000 – 24,000 | +1 to 2 classes | €10,000 (fossil boiler replacement) |
| Geothermal heat pump | €30,000 – 40,000 | +1 to 2 classes | €12,000 (fossil boiler replacement) |
| Centralised dual-flow MVHR (100–150 m² house, accessible loft) | €7,000 – 14,000 | Contributes to BBB/AAA | Enoprimes MVHR (amount calculated individually) |
| Solar panels (6 kWp, ~15 panels) | €12,000 – 16,000 | –0.5 class (own production) | Up to €10,000 (direct pre-financing) |
| Full comprehensive renovation (roof + walls + windows + heat pump + MVHR, 130 m² house) | €80,000 – 150,000 | +3 to 5 classes (E→A possible) | Up to €50,000+ (combined) |
Indicative ranges — Luxembourg market March 2026, 3% VAT included — data collected from certified tradespeople. Klimabonus amounts are those of the 2026 scheme in force since 1 January 2026 (subject to publication in the Mémorial). Actual prices vary depending on area, home configuration and site constraints.
Loft insulation (120 m², blown): €6,500
External wall insulation ETI (150 m² of façades, standard material): €25,000
12 triple-glazed PVC windows replaced: €12,500
Air-to-water heat pump + connections (oil boiler replacement): €20,000
Premium centralised dual-flow MVHR: €12,000
Approved energy advisor + EPC before + EPC after: €2,500
Total incl. VAT: ≈ €78,500
Estimated grants (Klimabonus + VAT + Enoprimes): –€35,000 to –€50,000 depending on final performance and social top-up
Estimated out-of-pocket cost: €28,500 – 43,500
All available grants in 2026 for detached house renovation in Luxembourg
Luxembourg’s distinctiveness compared to neighbouring countries lies in the generosity and variety of stackable grants. Here is the detail of every scheme applicable to a detached house in 2026.
1. Klimabonus Wunnen 2026 — the main state grant
The Klimabonus is the Luxembourg State’s central scheme for encouraging residential energy renovation. In 2026, the scheme was completely overhauled with flat-rate amounts expressed in €/m² or fixed amounts per installation. The main innovations of the 2026 scheme:
- Clear and readable flat-rate amounts — no more complex calculations based on installation capacity
- The former Tripartite bonus is integrated into the base amounts — no more separate grant to apply for
- Removal of the 10-year age condition for boilers to be replaced
- New bonus for ecological materials: natural insulation (wood fibre, hemp, sheep’s wool) earns up to €55/m² extra
- New grants for green roofs and façades
- Super-reduced VAT at 3% applicable from 10 years of property age (reduced from 20 years)
The maximum Klimabonus subsidy rate varies depending on renovation ambition:
| Renovation ambition | Klimabonus subsidy rate | Condition |
|---|---|---|
| Single-measure renovation (1 element, without energy advisory) | Fixed flat-rate amount per element | In-principle agreement before works |
| Multi-measure renovation with energy advisory, 1 EPC class improvement | 50% of eligible costs (base rate) | Approved energy advisor mandatory |
| 2 EPC class improvement | 50% + 20% bonus = 60% | EPC before and after works |
| 3 or more EPC class improvement | 50% + 40% bonus = 62.5% (ceiling) | EPC before and after works |
| Reaching class A or B after works | 62.5% + additional €2,000 bonus | Post-works EPC attesting class A or B |
The in-principle agreement from the single housing grant desk must be obtained before any start of works. This rule is absolute and without exception. Works started before the in-principle agreement result in the irreversible loss of Klimabonus grants, regardless of the performance level achieved. The 2026 Klimabonus is applicable with retroactive effect from 1 January 2026, subject to publication of the law in the Mémorial. The first applications can be submitted from 1 January 2026 via MyGuichet.lu.
2. Klimabonus social top-up — doubling for low-income households
Klimabonus recipients whose income does not exceed certain thresholds can request a Klimabonus social top-up from the Ministry of Housing, which can result in a doubling of the Klimabonus received. This can raise the effective coverage rate from 50% to 100% on eligible elements, within the limit of actual works costs. Exact income conditions and thresholds are available at logement.public.lu. If your household is potentially eligible, check your entitlement to the social top-up from the start of your project — it can radically transform your out-of-pocket cost.
3. Super-reduced VAT at 3% — 14 percentage points saved on the entire invoice
The super-reduced 3% VAT rate applies to all renovation works (insulation, heating, windows, ventilation, photovoltaics) in a home over 10 years old used as a primary residence in Luxembourg, provided works are carried out by a tradesperson registered with the Chamber of Skilled Trades. This 14-percentage-point VAT saving (17% – 3%) applies to the entire invoice — materials and labour — up to €357,000 of works. For an €80,000 renovation, the VAT saving represents approximately €11,200 compared to the standard rate.
4. Enoprimes — energy supplier grants
Enoprimes (managed by Enovos/Encevo and Creos) offer supplementary grants for certain types of works: thermal insulation of walls, roof and loft, heating system replacement (heat pump, condensing boiler), and dual-flow MVHR. These grants are calculated based on energy savings generated and paid after works completion. They are stackable with the Klimabonus. Absolute rule: the Enoprimes application must be submitted before signing the quote, through an approved Enoprimes partner. The partner tradesperson can manage the process on your behalf.
5. Municipal grants — up to €3,000 additional
Some Luxembourg municipalities offer supplementary financial grants for energy renovation works on their territory. Amounts vary from €1,500 to €3,000 depending on municipality, and not all offer a scheme. Some municipalities are particularly active (Luxembourg City, Strassen, Mamer, notably). Always enquire with your municipal administration before starting works. This simple step can earn you several additional thousands of euros.
6. Klimaprêt — subsidised-rate financing up to €100,000
The Klimaprêt (climate loan) is a loan offered by accredited Luxembourg banks to finance energy renovation works. The Luxembourg State covers an interest subsidy of 1.5%, up to 10% of the borrowed capital, on a maximum loan of €100,000 over 15 years. This allows financing of the remaining cost — after subsidies — without an immediate full cash outlay. To benefit, you must have previously obtained Klimabonus assistance. It is offered notably by BCEE (Spuerkeess), BGL BNP Paribas, and other accredited banks.
7. Accelerated tax depreciation for landlords
If you own a property rented out in Luxembourg, a 6% depreciation rate for 10 years is granted for renovation investment expenditure that has benefited from Klimabonus grants. This tax advantage makes renovating a rental property doubly profitable: direct grants upfront, and tax reduction over time.
Calculate your total grant amount in 2 minutes for your detached house in Luxembourg.
Simulate my grants →Steps in the right order — do not skip any stage
The chronology of steps is critical. A sequencing error can cost you tens of thousands of euros in grants. Here is the complete process, step by step.
Commission a Klima-Agence approved energy advisory (mandatory for multi-measure renovation)
The energy advisory is a complete energy audit of your home, carried out by an advisor approved by the Klima-Agence. It identifies thermal weak points, proposes costed renovation scenarios, calculates expected EPC gains, and establishes the technical file required for Klimabonus grants. Cost: €1,500 to €4,000 depending on the size and complexity of the property. This cost is partially reimbursed by the Klimabonus (approximately €1,000 to €1,500 for a detached house). The energy advisory is mandatory if you wish to renovate more than one element of the thermal envelope and access the highest subsidy rates. For a single element, a simplified version (€400 to €500, subsidised) is sufficient. The list of approved advisors is available at klima-agence.lu.
Request quotes from certified tradespeople
Based on the energy advisory report, request quotes from at least 3 tradespeople registered with the Luxembourg Chamber of Skilled Trades for each work item. Verify that your tradespeople are Enoprimes partners if you wish to benefit from Enoprimes grants. The approved energy advisor can verify the technical compliance of received quotes — a step that secures your file and can unlock an additional €100 for this compliance check.
Request the Enoprimes in-principle agreement — BEFORE signing any quotes
If you wish to benefit from Enoprimes, the application must be submitted before signing the installation quote. Your Enoprimes partner tradesperson submits the application simultaneously with the quote. Any quote signed without prior Enoprimes agreement permanently invalidates those grants. Once the Enoprimes agreement is obtained and the grant offer signed, you can sign the quote.
Request the Klimabonus in-principle agreement — BEFORE any start of works
Submit your Klimabonus in-principle agreement application via MyGuichet.lu (or by registered mail to the single housing grant desk). The application must include the energy advisory report and compliant quotes. Wait for validation before scheduling works start. Processing times can vary from 2 to 8 weeks depending on the period. Factor in this delay when planning your works schedule.
Carry out works with an approved tradesperson
Once both in-principle agreements are obtained (Klimabonus and Enoprimes), works can begin. Your approved energy advisor can provide site monitoring. For certain works (heat pump in particular), the Chamber of Skilled Trades must be notified within the month following commissioning.
Have an « as-built » EPC established after works (if comprehensive renovation)
To benefit from Klimabonus bonuses linked to EPC class improvements (20% bonus for +2 classes, 40% for +3 classes), you must have a new energy passport established after works by an approved expert. This « as-built » EPC certifies the performance actually achieved and unlocks the increased subsidy amounts. Cost: €300 to €600.
Apply for grant settlement after works
Once works are completed and invoices received, submit your Klimabonus settlement application via MyGuichet.lu, accompanied by final invoices and the energy advisor’s final report. Enoprimes are paid by your partner tradesperson (who submits supporting documents directly to Enoprimes) approximately 4 weeks after file validation. The Klimabonus is paid by the single desk within a similar timeframe after processing of the complete file.
The first 2026 Klimabonus in-principle agreement application must be submitted between 1 January 2026 and 31 December 2030. Invoices must be issued between 1 January 2026 and 31 December 2035. Settlement applications must be submitted within 4 years from 31 December of the invoice’s calendar year. Plan well in advance to avoid missing deadlines at the last moment.
3 costed renovation scenarios for a detached house in Luxembourg
To concretely illustrate the impact of the Luxembourg grant system, here are three project profiles representative of the Grand Duchy’s detached house stock.
Scenario A — Targeted partial renovation: roof insulation only
130 m² house, 1980s, EPC class G, owner not wishing an immediate comprehensive project.
| Item | Amount |
|---|---|
| Unused loft insulation (110 m², blown cellulose wool) | €5,500 |
| Simplified energy advisory (single measure) | €400 |
| EPC before works | €350 |
| Total incl. VAT (3%) | €6,250 |
| Klimabonus loft insulation (estimate) | − €2,500 |
| VAT saving (3% vs 17%) | − €875 |
| Estimated out-of-pocket cost | ≈ €2,875 |
Expected EPC gain: move from G to F-E. Heating savings: 25 to 30%. Payback period: 4 to 6 years.
Scenario B — Intermediate renovation: insulation + heating replacement
130 m² house, 1985, EPC class F, oil heating, owner with budget of €40,000–50,000.
| Item | Amount |
|---|---|
| Unused loft + sloped roof insulation (110 m²) | €12,000 |
| Air-to-water heat pump (oil boiler replacement, existing underfloor heating) | €19,000 |
| 10 triple-glazed PVC windows replaced | €11,000 |
| Approved energy advisory + EPC before + EPC after | €2,200 |
| Total incl. VAT (3%) | €44,200 |
| Klimabonus air-to-water heat pump (fossil replacement) | − €10,000 |
| Klimabonus roof insulation + windows (estimate) | − €6,000 |
| Enoprimes (estimate) | − €1,500 |
| VAT saving (3% vs 17%) | − €6,188 |
| Estimated out-of-pocket cost | ≈ €20,500 |
Expected EPC gain: move from F to C-D (2 classes). Heating savings: 55 to 70%. Grant coverage rate: ~54%.
Scenario C — Ambitious comprehensive renovation targeting BBB class
150 m² house, 1975, EPC class H, oil heating, owner targeting maximum performance.
| Item | Amount |
|---|---|
| Full sarking roof insulation (130 m²) | €22,000 |
| ETI exterior walls — ecological wood fibre materials (160 m² façades) | €30,000 |
| 14 triple-glazed windows and openings replaced (wood) | €21,000 |
| Geothermal heat pump + underfloor heating (complete replacement) | €38,000 |
| Premium centralised dual-flow MVHR | €14,000 |
| 8 kWp solar panels | €14,000 |
| Approved energy advisory + EPC before + EPC after + Blower Door test | €3,500 |
| Total incl. VAT (3%) | €142,500 |
| Klimabonus geothermal heat pump | − €12,000 |
| Klimabonus insulation + windows + MVHR (estimate, ecological materials) | − €22,000 |
| Klimabonus photovoltaics (8 kWp) | − €10,000 |
| Enoprimes (heat pump + MVHR + insulation, estimate) | − €3,500 |
| Municipal grants (estimate) | − €2,000 |
| VAT saving (3% vs 17%) | − €19,950 |
| Estimated out-of-pocket cost | ≈ €73,050 |
| With Klimabonus social top-up (eligible household): grants potentially doubled on insulation Klimabonus | up to −€22,000 additional |
Expected EPC gain: move from H to A/B (BBB class achievable depending on final insulation). Heating savings: 75 to 85%. Estimated property value increase: +15 to 20% on sale price. Klimabonus and Enoprimes amounts are estimates — exact amounts are calculated individually based on actual performance achieved.
Impact on property value: why renovation increases your assets
In Luxembourg, the property market strongly values energy performance for a simple reason: with among the highest per-m² prices in Europe, buyers are extremely attentive to future running costs and quality of life. Multiple studies and market data confirm this impact:
- A class A or B property sells for 10 to 15% more than an equivalent class E or F property in the same neighbourhood.
- Properties in class G-H-I suffer a 15 to 25% discount on the Luxembourg market, as buyers anticipate compliance costs.
- Time to sell is 2 to 3 times longer for poorly rated properties.
- Buyers negotiate far more aggressively on energy-intensive properties, knowing that the EU Energy Performance of Buildings Directive (EPBD) will impose growing requirements.
- Moving from class E to class B represents an annual heating saving of approximately €2,000, i.e. €20,000 over 10 years and €40,000 over 20 years — a concrete, quantifiable value increase.
If you are planning to sell your home within 5 to 10 years, energy renovation before listing is often a net positive investment: Klimabonus grants cover a significant share of works, and the resulting property value increase frequently exceeds the out-of-pocket cost. A simple calculation: for a property at €800,000 (Luxembourg median price 2026), a 12% value increase represents €96,000 — far more than an out-of-pocket cost of €30,000 to €50,000 after grants.
5 fatal mistakes to avoid in your renovation
Starting works without the Klimabonus in-principle agreement
This is the most costly and most common mistake. Owners who sign an insulation quote or order a heat pump without having obtained the in-principle agreement from the single desk permanently lose the Klimabonus grant for those works — sometimes several tens of thousands of euros. The rule is without exception: in-principle agreement before any start. The same applies for Enoprimes: agreement before signing the quote. Allow 4 to 8 weeks to obtain agreements and factor this delay into your works schedule.
Replacing the boiler before insulating
Installing a heat pump in a home whose roof loses 30% of its heat is a technical and economic mistake. The heat pump will be oversized, operate at high flow temperatures (less efficient), and savings will be disappointing. A water-to-water heat pump thrives in a well-insulated home with low-temperature emitters (underfloor heating, low-temperature radiators). Your approved energy advisor will tell you precisely the right sequencing for your home.
Choosing a tradesperson not registered with the Luxembourg Chamber of Skilled Trades
Only tradespeople registered with the Grand Duchy’s Chamber of Skilled Trades are authorised to carry out works eligible for Luxembourg grants. Cross-border tradespeople (French, Belgian, German) working in Luxembourg without registration with the Luxembourg Chamber do not entitle you to grants. French RGE certification has no legal value in Luxembourg. Always check your tradesperson’s registration on the Chamber of Skilled Trades website before signing anything.
Renovating item by item without an overall vision
Carrying out « piecemeal » renovations without an overall plan leads to incompatible works, untreated thermal bridges, and reduced effectiveness. A home where windows have been replaced but walls not insulated has thermal bridges at the façade-window junctions that partially cancel out the benefit of the new windows. The approved energy advisor establishes a coherent renovation plan that treats the building as a system, maximises EPC gains and optimises the order of works to avoid redoing the same wall or ceiling twice.
Neglecting ventilation in a home made airtight
A renovated home — insulated, with new airtight windows — is far more hermetic than before works. Without appropriate dual-flow MVHR, this airtightness rapidly generates humidity build-up, CO₂, indoor pollutants, and mould on residual cold surfaces. Failing to integrate ventilation into the renovation project compromises air quality, occupant health, and the durability of insulation materials. Dual-flow MVHR must be planned and installed at the same time as the envelope renovation, not after.
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Frequently asked questions about detached house energy renovation in Luxembourg
My house is 25 years old. Am I eligible for the 2026 Klimabonus?
Yes. The 2026 Klimabonus scheme applies to all homes over 10 years old since the date the building permit was issued. A 25-year-old house comfortably meets this condition. You are also eligible for the super-reduced 3% VAT on all renovation works. If your house was built less than 10 years ago, only technical installations (heat pump, photovoltaics) may be eligible for the Klimabonus for technical installations, but thermal envelope subsidies do not apply.
Is an energy advisory genuinely mandatory for all projects?
No, it is mandatory only if you wish to renovate more than one element of the thermal envelope and access the highest subsidy rates (60 to 62.5%). For a single element (for example only loft insulation, or only window replacement), you can access a simplified process without a full energy advisory, but with a one-off advisor accompaniment (€400 subsidised cost + €100 for quote compliance check). In practice, if your project involves the heat pump, windows AND insulation simultaneously, the full energy advisory is strongly recommended — it optimises total grants and ensures technical coherence of the project.
Can I spread my renovation over several phases to avoid financing everything at once?
Yes, this is entirely possible and even advisable if your budget does not allow an immediate comprehensive renovation. The energy advisory establishes a phased renovation plan determining the optimal order of works. You can request a Klimabonus in-principle agreement for the first-phase works, carry them out, then submit a new application for the next phase. Each phase is treated independently. The important thing is that each in-principle agreement application is submitted before the corresponding works start, and that initial applications are submitted before 31 December 2030.
What happens if I sell my home after receiving the Klimabonus?
If you sell your property after carrying out works subsidised by the Klimabonus, the new owner who acquires the property waives the grant in favour of the former owner who made the investments — meaning you retain the grants received. The new owner cannot re-apply for the same grants for the same installations. They can however carry out new renovation works and apply for grants for these new investments.
Is the Klimabonus subject to income tax in Luxembourg?
No. The Klimabonus is not considered taxable income for individuals and does not need to be declared in the income tax return. For landlord-owners using the 6% accelerated depreciation rate, consulting a tax advisor is recommended to correctly optimise the declaration of renovation expenditure and corresponding depreciation.
How long does a comprehensive renovation project take in Luxembourg, from first step to completed works?
For a full comprehensive renovation (insulation + heating + windows + ventilation), generally allow 4 to 9 months from first contact to completed project: 2 to 4 weeks to find an available approved energy advisor and complete the audit; 3 to 6 weeks to receive the energy advisory report; 2 to 4 weeks to receive and have tradesperson quotes validated; 2 to 6 weeks for the Klimabonus in-principle agreement; 4 to 12 weeks for works depending on tradesperson availability. The shortage of qualified construction labour in Luxembourg often extends these timelines in 2026 — anticipate your project as early as possible, ideally 6 months before your target works start date.
Can my tradesperson be a cross-border worker (French, Belgian, German)?
Yes, under conditions. A cross-border tradesperson can work in Luxembourg provided they are registered with the Grand Duchy’s Chamber of Skilled Trades (or are providing a temporary service under legal conditions). Simple French RGE certification or registration with a Belgian or German chamber of trades is not sufficient to qualify for Luxembourg grants. Before choosing a cross-border tradesperson, explicitly verify their legal status in Luxembourg — it is their responsibility to prove it to you. If in doubt, consult the list of approved partners on enoprimes.lu or klima-agence.lu.
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