What is the best insulation in Luxembourg to maximise Klimabonus aid?

In 2026, ecological bio-sourced materials (wood fibre, cellulose wadding, expanded cork, hemp wool) are the best subsidised by the Klimabonus 2026: up to €115/m² for an exterior element with performance I, compared with €85/m² for mineral insulation (glass wool/rock) and €60/m² for a standard material. The additional bonuses (+ €15/m² per criterion) for recycled content, ecological certification and greening are cumulative and can bring the total aid to €130--145/m². In many cases, the net cost after aid is lower with eco-friendly insulation.

Can Klimabonus, Enoprimes and VAT at 3 % for insulation be combined?

Yes, these three mechanisms can be fully combined. The Klimabonus (a subsidy from the Luxembourg government, paid by the Environmental Administration) and the Enoprimes (premiums from energy suppliers Enovos/Creos, ranging from €4 to €12/m²) apply to the cost of the work, excluding VAT. VAT at 3 % reduces the tax burden on the price including VAT. In addition, the Klimabonus social Topup (doubling of income support, paid by the Ministry of Housing) can also be combined with the basic grants. For a household eligible for the social Topup, total subsidies can cover 60 to 80 % of the cost of the

Do I need planning permission to insulate my home in Luxembourg?

No planning permission is required for internal insulation (ITI) that does not affect the load-bearing structures or alter the external appearance. For external insulation (ITE) that changes the appearance of the facade, planning permission issued by the mayor is normally required. In areas subject to heritage or aesthetic restrictions (UNESCO protected sectors, SPR, historic areas), the conditions may be restrictive or even prohibitive for certain ITE systems. Always check with your local council and via the P

Is polystyrene still subsidised by the Klimabonus in Luxembourg?

From 1 January 2024, conventional expanded polystyrene (EPS), extruded polystyrene (XPS) and polyurethane (PUR) will no longer be subsidised by the Klimabonus. The exception remains: fossil-based insulation made from more than 50 % of recycled materials remains eligible, as does XPS/EPS for walls against floors and slabs below floors against floors (where high-performance alternatives in damp environments are limited). In practice, for all other uses (external walls, roofs, raised floors), bio-sourced and mineral materials are to be preferred in order to optimise support.

How much does it cost to fully insulate a 120 m² house in Luxembourg?

For a 120 m² detached house in Luxembourg, a complete renovation of the envelope (roof, external walls, low floor) represents a gross investment of €40,000 to €80,000 excluding VAT, depending on the techniques and materials chosen. With the combination of Klimabonus 2026 support (ecological materials, performance I), Enoprimes and VAT at 3 %, the remaining outlay can be as little as €20,000 to €40,000 - and even less for households eligible for the Klimabonus Social Topup. This work can generally reduce heating consumption by 2 to 3 times, with a return on investment of

What is the best insulation in Luxembourg to maximise Klimabonus aids?

In 2026, bio-based ecological materials (wood fibre, cellulose wadding, expanded cork, hemp wool) are best subsidised by Klimabonus 2026: up to €115/m² for an external element in performance I, compared to €85/m² for mineral insulation (glass/rock wool) and €60/m² for standard material. Additional bonuses (+€15/m² per criterion) for recycled content, ecological certification and vegetation are cumulable and can bring total aid to €130-145/m². In many cases, net cost after aids is lower with ecological insulation than with non-subsidised polystyrene, even if the latter costs less to buy.

Can Klimabonus, Enoprimes and 3% VAT be combined for insulation?

Yes, these three mechanisms are fully cumulable. Klimabonus (Luxembourg Government subsidy, paid by Environment Administration) and Enoprimes (energy supplier premiums Enovos/Creos, €4 to €12/m²) apply to net works cost. 3% VAT reduces the tax burden on all-inclusive price. Furthermore, Klimabonus social top-up (double aids under income conditions, paid by Housing Ministry) is also cumulable with base premiums. For an eligible household for social top-up, total aids can cover 60 to 80% of works cost.

Is a building permit required for home insulation in Luxembourg?

For internal insulation (ITI) not affecting load-bearing structures and not modifying the exterior appearance, no building permit is required. For external insulation (ETE) modifying facade appearance, a building permit issued by the mayor is in principle necessary. In areas subject to heritage protection or aesthetic conditions (UNESCO-protected sectors, SPR, historic zones), conditions may be restrictive or even prohibitive for certain ETE systems. Always verify with your municipality and via PAG-GEOPORTAAL before choosing your insulation technique.

Is polystyrene still subsidised by Klimabonus in Luxembourg?

Since 1 January 2024, expanded polystyrene (EPS), extruded polystyrene (XPS) and conventional polyurethane (PUR) are no longer subsidised by Klimabonus. Exception maintained: insulants composed of more than 50% recycled material remain eligible, as well as XPS/EPS for below-ground walls and lower slabs against soil (where high-performance alternatives in humid environments are limited). In practice, for all other uses (external walls, roof, raised floor), bio-based and mineral materials should be prioritised to optimise aids.

What does complete insulation of a 120 m² home cost in Luxembourg?

For a 120 m² single-family home in Luxembourg, complete envelope renovation (roof, external walls, ground floor) represents a gross investment of €40,000 to €80,000 net depending on techniques and materials chosen. With combined Klimabonus 2026 (ecological materials, performance I), Enoprimes and 3% VAT, remaining cost can drop to €20,000-40,000 - and even less for households eligible for Klimabonus social top-up. These works typically halve to triple heating consumption, with return on investment of 8 to 15 years depending on energy type used.

Welche ist die beste Dämmung in Luxemburg zur Maximierung von Klimabonus-Hilfen?

In 2026 sind biogene ökologische Materialien (Holzfaser, Zellulosewatte, expandierter Kork, Hanfwolle) am besten von Klimabonus 2026 gefördert: bis zu 115 €/m² für externe Element in Performance I, gegenüber 85 €/m² für mineralische Dämmung (Glas-/Steinwolle) und 60 €/m² für Standardmaterial. Zusatzboni (+15 €/m² pro Kriterium) für Recyclinggehalt, ökologische Zertifizierung und Begrünung sind kumulierbar und können Gesamthilfe auf 130-145 €/m² bringen. In vielen Fällen ist Nettokosten nach Hilfen mit ökologischer Dämmung niedriger als mit nicht gefördertem Polystyrol, obwohl letzteres güns

Können Klimabonus, Enoprimes und 3% MwSt. für Dämmung kombiniert werden?

Ja, diese drei Mechanismen sind vollständig kumulierbar. Klimabonus (Luxemburger Staatshilfe, gezahlt von Umweltadministration) und Enoprimes (Energieversorger-Prämien Enovos/Creos, 4-12 €/m²) gelten für Nettoarbeitskosten. 3% MwSt. reduziert Steuerbelastung auf Bruttobetrag. Weitere: Klimabonus Sozial-Zuschlag (Doppelhilfe unter Einkommensbedingungen, gezahlt von Wohnungsministerium) ist auch mit Basis-Prämien kumulierbar. Für berechtigten Haushalt für Sozial-Zuschlag können Gesamthilfen 60-80% der Arbeitskosten abdecken.

Window Prices in Luxembourg 2026: Costs, Materials and Grants

In Luxembourg, replacing windows costs between €500 and €2,400 per opening, installation included, depending on window type (standard, French door or bay window), material (PVC, aluminium, wood) and glazing (double or triple). By combining the Klimabonus 2026 (€70/m² of glazing replaced), Enoprimes, 3% VAT and municipal grants, net costs can be reduced by 15 to 25%. Here are all verified prices and available grants to plan your 2026 project.

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Window prices in Luxembourg by type — installation included (2026)

The prices below are ranges charged by companies operating in Luxembourg, installation included, for standard dimensions. They reflect the local premium on labour costs and delivery lead times.

Standard window (approx. 1.23 m × 1.48 m)

Material	Double glazing — installed	Triple glazing — installed	Lifespan
PVC	€500 — €650	€750 — €900	30 — 40 years
Aluminium	€700 — €950	€950 — €1,200	40 — 50 years
Wood	€750 — €1,100	€1,000 — €1,400	40 — 60 years (with maintenance)
Wood-alu	€900 — €1,300	€1,200 — €1,700	40 — 60 years

French door / patio door (approx. 0.90 m × 2.10 m)

Material	Double glazing — installed	Triple glazing — installed
PVC	€800 — €1,100	€1,200 — €1,500
Aluminium	€1,000 — €1,400	€1,400 — €1,800
Wood / Wood-alu	€1,100 — €1,600	€1,500 — €2,100

Sliding bay window (approx. 2.40 m × 2.10 m)

Material	Double glazing — installed	Triple glazing — installed
PVC	€1,500 — €2,000	€2,100 — €2,700
Aluminium	€1,800 — €2,400	€2,400 — €3,300

Good to know PVC accounts for 50–60% of windows installed in Luxembourg. It offers the best value for money and easily meets Klimabonus thresholds (Uw ≤ 1.0 W/m²K). Aluminium is preferred for large surfaces or contemporary façades. Wood and wood-alu are standard in listed buildings or traditional architecture.

Installation costs in detail: renovation vs new build

Installation typically accounts for 20 to 30% of the total window price in Luxembourg. The cost varies significantly depending on the technique and site conditions.

Three installation techniques

Technique	Description	Labour cost alone	Best for
Overlay installation (renovation)	New frame fixed over existing reveal, old frame kept	€100 — €200 / window	Quick replacement, tight budget
Full removal (renovation)	Old frame fully removed, masonry made good, new window in rebate	€200 — €400 / window	Maximum thermal performance, Klimabonus
New-build installation	Window installed before wall cladding	€100 — €200 / window	New construction or heavy renovation

Important Overlay installation retains the old frame, which reduces effective glazed area and may leave thermal bridges. To qualify for Klimabonus 2026, full removal is strongly recommended to guarantee compliant airtightness and the required Uw performance.

Typical budget for a complete house (10–12 windows)

Configuration	Estimated gross budget (installation included)
10 PVC double-glazed windows	€5,000 — €6,500
10 PVC triple-glazed windows	€7,500 — €9,000
10 aluminium triple-glazed windows	€9,500 — €12,000
Mix: 8 windows + 2 French doors, PVC triple	€8,400 — €10,200
Mix: 8 windows + 1 aluminium bay window, double	€8,800 — €12,500

What drives window prices

For equivalent performance, a quote can vary by a factor of two depending on the choices made. Here are the six key factors to understand before signing.

1. Glazing type: the biggest cost driver

Triple glazing costs 30 to 40% more than modern Low-E argon double glazing. For a house with 10 PVC windows, this represents an extra €2,000 to €3,000. However, since the Klimabonus 2026 grant is calculated in €/m², the extra cost is partially offset for large surfaces. For small surfaces or well-exposed south-facing façades, high-performance double glazing (Uw ≤ 1.0 W/m²K) often remains the most cost-effective solution.

2. Frame material

PVC is the least expensive and most common. Aluminium costs 20 to 30% more than PVC for similar thermal performance (provided a quality thermal break is fitted). Wood and wood-alu can cost 50 to 100% more than PVC, but have a lower carbon footprint — which may optimise some of the Klimabonus 2026 ecological bonuses.

3. Dimensions and opening type

Non-standard windows (large width, arched shape, dormer) are made to measure and can cost 2 to 5 times a standard window. Tilt-and-turn windows are the most popular and best-priced; sliding windows are slightly cheaper to buy but more complex to seal properly.

4. Built-in options

A motorised roller shutter integrated in a custom box adds €300 to €600 per window. Reinforced acoustic glazing (asymmetric laminated type 6/16/4) adds €80 to €150 per m². Anti-burglary glazing (minimum P2A) adds €100 to €200 per window.

Key point The Uw coefficient of the complete window (frame + glazing) determines your Klimabonus grant level. Do not confuse Ug (glazing alone) with Uw (whole window): Uw is always higher than Ug, i.e. less insulating. Always check the Uw stated on the manufacturer’s technical data sheet, not the Ug some quotes highlight.

Financial grants for windows in Luxembourg in 2026

Four sources of aid can be combined for window replacement in Luxembourg. Here is the detail of each, with verified amounts.

1. Klimabonus 2026 — €70/m² of glazing replaced

Since 1 January 2026, the new Klimabonus Wunnen scheme (bill 8585, retroactive) calculates the grant for window replacement on the basis of a flat rate of €70/m² of glazing replaced. This amount now includes the former Tripartite bonus.

Opening type	Indicative glazed area	Estimated Klimabonus 2026 grant
Standard window (1.23 m × 1.48 m)	≈ 1.82 m²	≈ €127
French door (0.90 m × 2.10 m)	≈ 1.89 m²	≈ €132
Sliding bay window (2.40 m × 2.10 m)	≈ 5.04 m²	≈ €353

Good to know The Klimabonus grant may only be awarded once per structural element. The building must be more than 10 years old (building permit date). The first application for approval in principle must be filed via MyGuichet.lu before work begins, between 1 January 2026 and 31 December 2030. Invoices must be issued between 1 January 2026 and 31 December 2035.

2. Enoprimes — complementary grant from your energy supplier

Energy suppliers active in Luxembourg (Enovos, LEO, etc.) pay additional grants through the Enoprimes programme for the replacement of poorly performing windows with reinforced insulating glazing models. The application must be made before signing the purchase order: a file opened after the order is automatically rejected.

3. 3% VAT — direct saving on your bill

For a primary residence in Luxembourg, renovation work (including window replacement) benefits from the super-reduced VAT rate of 3% instead of 17%, saving 14 percentage points on the total invoice. This tax benefit is capped at €50,000 in VAT savings per dwelling. The property must be used as the owner’s or tenant’s primary residence and be more than 10 years old.

4. Municipal grants — depends on your municipality

Some Luxembourg municipalities offer additional grants for energy renovation, which can be combined with Klimabonus. Amounts range from €1,500 to €3,000 depending on the municipality for a full renovation. Check the Klima-Agence simulator (aides.klima-agence.lu) for grants available in your municipality.

5. Klimaprêt — financing the remaining cost

If your budget does not cover the full cost of the work, the Klimaprêt allows you to borrow up to €100,000 over 15 years from an approved bank, with a State interest subsidy of 1.5% (capped at 10% of the principal, i.e. a maximum of €10,000). This loan can be combined with the Klimabonus and Enoprimes.

Sources: guichet.public.lu (Klimabonus 2026 scheme); gouvernement.lu (31 December 2025 press release, bill 8585); enoprimes.lu; pfi.public.lu (VAT on housing); klima-agence.lu

Net cost after grants: worked examples

The two examples below concretely illustrate the impact of grants on a Luxembourg homeowner’s budget. Klimabonus amounts are estimates based on the €70/m² flat rate of the 2026 scheme; Enoprimes amounts are indicative and depend on your supplier.

Example 1 — 1990s house, 10 PVC triple-glazed windows

Item	Amount
10 PVC triple-glazed windows, installed (full removal)	€8,250 excl. VAT
VAT saving (14 percentage points, 3% instead of 17%)	− €1,155
Klimabonus 2026 (≈ 1.82 m² × €70 × 10 windows)	− €1,274
Estimated Enoprimes (indicative)	− €200 to €400
Estimated net cost	€5,470 — €5,870

Example 2 — 1980s house, 8 PVC windows + 1 aluminium double-glazed bay window

Item	Amount
8 PVC double-glazed windows, installed	€4,560 excl. VAT
1 aluminium double-glazed bay window, installed	€2,000 excl. VAT
VAT saving	− €918
Klimabonus 2026 (8 × €127 + 1 × €353)	− €1,369
Estimated Enoprimes (indicative)	− €150 to €300
Estimated net cost	€4,370 — €4,520

Calculate your specific case These examples are indicative. Klimabonus amounts depend on your exact window areas and the final conditions of the 2026 scheme (law currently being published in the Mémorial). Use the Klima-Agence simulator or our renov.lu simulator for a personalised estimate.

Steps before signing your quote

The chronology is critical: one step out of order can cost you all your grants. Here is the correct sequence for window replacement in Luxembourg in 2026.

Apply for Enoprimes approval BEFORE signing anything

Contact your energy supplier (Enovos, LEO, etc.) or go through an enoprimes.lu partner installer. Approval must be obtained before signing the purchase order, without exception.

Apply for Klimabonus approval in principle via MyGuichet.lu

Before starting work, submit your application for approval in principle to the Guichet unique des aides au logement (MyGuichet.lu). For a single-element replacement without an energy audit, the simplified procedure applies. For multiple elements, a certified energy audit is mandatory.

Check municipal grants

Check with your municipal administration or via the Klima-Agence simulator (aides.klima-agence.lu) for grants available in your municipality.

Sign the quote and arrange Klimaprêt if needed

Once Klimabonus and Enoprimes approvals are in hand, sign a quote from a « Klima-Agence certified — Artisan » contractor. If you need a Klimaprêt, arrange it with an approved bank before work begins.

Complete the work and collect invoices

Invoices must be issued between 1 January 2026 and 31 December 2035. Check that each invoice states window type, Uw value, area and unit price — these details are required for Klimabonus payment.

Apply for grant payment

After work is complete, submit your Klimabonus payment application via MyGuichet.lu. The deadline is 31 December 2039. Also submit supporting documents to your energy supplier for Enoprimes, and apply for 3% VAT refund from the AED if it was not directly applied.

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5 mistakes that blow the window budget in Luxembourg

1. Signing the purchase order before obtaining Enoprimes and Klimabonus approvals

This is the most common and costly mistake. For Enoprimes, any order signed before approval makes the application automatically inadmissible. For Klimabonus, starting work without approval in principle leads to rejection. In both cases, you lose hundreds to thousands of euros in grants.

2. Confusing Ug and Uw on the quote

Ug is the thermal value of the glazing alone. Uw is that of the complete window (frame + glazing) — this is the coefficient the Klimabonus assesses. Glazing with Ug = 0.5 can give a Uw of 0.8 or 1.1 depending on frame quality. Always insist that Uw is explicitly stated on the quote and product technical data sheet.

3. Choosing overlay installation to save money in the short term

Overlay installation costs €100–€200 less per window than full removal. But it retains the thermal bridges of the old frame, reduces effective glazed area and can compromise airtightness — and therefore Klimabonus eligibility. The short-term saving often becomes a long-term cost.

4. Getting only one quote

In Luxembourg, prices for external joinery can vary by 30 to 50% between suppliers for identical specifications. Get at least 3 detailed quotes, making sure each one specifies the same Uw, material, installation technique and warranties.

5. Forgetting to check masonry condition before budgeting

Degraded window reveals (cracks, settlement, embedded moisture) can add €100–€300 per window in masonry repair work not included in the initial quote. Have existing reveals inspected during the measurement visit so these works can be priced from the outset.

Frequently asked questions — Window prices in Luxembourg

What is the average price of a PVC window in Luxembourg in 2026, installation included?

A standard PVC window (1.23 m × 1.48 m) costs between €500 and €650 with double glazing, and between €750 and €900 with triple glazing, installed via full frame removal. These prices include bespoke manufacturing, delivery and installation by a certified professional in Luxembourg.

How much does a bay window cost installed in Luxembourg?

A sliding bay window of approx. 2.40 m × 2.10 m costs between €1,500 and €2,000 for PVC double glazing, and between €2,400 and €3,300 for aluminium triple glazing, fully installed. A Klimabonus grant of approximately €353 (€70/m²) is deducted, plus the VAT saving.

Does the Klimabonus 2026 cover window replacement?

Yes. The Klimabonus Wunnen 2026 scheme provides a flat-rate grant of €70/m² of glazing replaced. To be eligible, the building must be more than 10 years old, work must be carried out by a certified contractor, and an application for approval in principle must be filed via MyGuichet.lu before work begins.

Can Klimabonus, Enoprimes and 3% VAT be combined for windows?

Yes, these three types of aid are fully stackable. You can also add municipal grants if your municipality offers them. The 3% VAT applies directly on the invoice or can be refunded afterwards. Enoprimes must be applied for before signing the purchase order. Klimabonus requires approval in principle before work begins.

How long does replacing 10 windows take?

Bespoke manufacturing takes 4 to 8 weeks depending on the material. Installation for a house with 10 to 12 windows typically takes 1 to 2 working days. Allow 2 to 3 months between signing the quote and completion, plus Klimabonus and Enoprimes administrative lead times.

Does a certified contractor need to install the windows for Klimabonus eligibility?

Yes. For Klimabonus, work must be carried out by an approved company (certified « Klima-Agence certified — Artisan ») or supervised by a certified energy advisor. A non-certified contractor automatically disqualifies you from Klimabonus grants, even if the window installed technically meets the requirements.

Simulate my window grants Free quote

Guichet.public.lu — Financial aid for energy renovation without energy audit (Klimabonus 2026 scheme): guichet.public.lu
Luxembourg Government — Extension and partial adaptation of Klimabonus Wunnen (31 December 2025, bill 8585): gouvernement.lu
ENR LUX — Klimabonus 2026 new grant amounts (windows: €70/m²):
Enoprimes.lu — Window replacement grant: enoprimes.lu
pfi.public.lu — Super-reduced VAT at 3% on housing: pfi.public.lu
Klima-Agence — Grant programmes and simulator: klima-agence.lu
Renov.lu — Window prices in Luxembourg, installation included: renov.lu

The Klimabonus 2026 amounts stated (€70/m²) are sourced from specialist publications and consistent with bill 8585 (gouvernement.lu, 31 December 2025). As the law was still being published in the Mémorial at the time of writing (March 2026), definitive conditions should be verified at guichet.public.lu or via the Klima-Agence simulator. Window prices are indicative ranges observed in Luxembourg and may vary by supplier. Renov.lu cannot be held responsible for regulatory changes occurring after the update date.