Combining Renovation Grants in Luxembourg: Strategy to Maximise Your Funding

Most homeowners don’t realise they can combine up to 4 different funding sources on the same renovation project.

Result: they miss out on €15,000 to €30,000 in free financing.

This guide shows exactly which grants combine, how to organise them, and how to transform an “expensive” renovation into an affordable investment.

The 4 combinable grants in Luxembourg

In Luxembourg, you can combine:

Cannot be combined (choose one or other): ❌ Luxembourg grants + French/Belgian grants (incompatible) ❌ Two Klimabonus applications for same works ❌ Professional + private homeowner grants

Real example: Complete renovation €80,000

Situation: 1985 house in Luxembourg, comprehensive renovation (heat pump + insulation + windows + painting).

Initial budget without grants

(Contractors typically add ~€10,000 due to project complexity.)

Real budgeted cost: €80,000

Progressive application of grants

STEP 1: 3% VAT (applied automatically)

All works above are eligible for 3% VAT (building over 20 years).

Replacing 17% VAT with 3%:

• 17% VAT: €10,200
• 3% VAT: €1,800
• VAT savings: €8,400

Cost after 3% VAT = €70,200 - €8,400 = €61,800

STEP 2: Klimabonus (MyGuichet application)

Klimabonus-eligible works:

• Air-to-water heat pump: €8,000 (base + replacement bonus)
• Wall insulation: €6,000 (30% capped)
• Windows: €3,000 (30% capped)
• Total Klimabonus: €17,000

STEP 3: Topup Social (if income under €120,000)

If modest income:

• Standard Klimabonus: €17,000
• Topup Social (×2): €17,000 additional
• Total energy aid: €34,000

Cost after Klimabonus + Topup = €61,800 - €34,000 = €27,800

STEP 4: Enoprimes (10-20% additional)

Supplementary Enoprimes on certain items (insulation, heat pump):

• Base Enoprimes: €2,500 (10-20% on €25,000 energy works)

Cost after Enoprimes = €27,800 - €2,500 = €25,300

STEP 5: Municipal grant

Most municipalities offer €500 to €2,000 for energy renovation:

• Example Luxembourg City: €1,500 for comprehensive renovation

Final cost = €25,300 - €1,500 = €23,800

Summary of combined grants

Without grant optimisation: €80,000 With full optimisation: €33,600 Difference: €46,400 saved

Application sequence: The optimal strategy

To correctly combine grants, follow this sequence:

1. BEFORE works: Check eligibility

Checklist:

• ✅ Building over 20 years? (for 3% VAT)
• Income under €120,000? (for Topup Social)
• ✅ Energy works? (for Klimabonus)
• ✅ Does my municipality offer grants? (check commune website)

2. Contact contractor and mention grants

Tell your contractor: “I want 3% VAT, I’ll apply for Klimabonus, and submit municipal application. Please prepare quotation and invoicing accordingly.”

Contractor must:

• Invoice 3% VAT only
• Detail energy works separately
• Provide Klimabonus documents (certificates, technical performance)

3. Apply for Klimabonus (MyGuichet.lu)

Critical timing: Apply for Klimabonus BEFORE starting works.

Duration: 10-15 days for pre-approval, then you can start.

4. During works: Nothing required

Enoprimes and municipal grants are requested after/during. The key is having Klimabonus pre-approved.

5. After works: Finalise grants

Klimabonus final (10 days): Submit invoice and photos.

Enoprimes (automatic): Paid with Klimabonus if eligible.

Municipal grant (1-3 months): Submit application to town hall with invoices and documentation.

Grants by work type

If you install a heat pump

Real cost of heat pump after grants: €15,000 - €38,000 = FREE to €3,000 max (depending on grants obtained).

If you insulate walls

If you replace windows

Common pitfalls when combining grants

❌ Pitfall 1: Start works before Klimabonus pre-approval Result: No Klimabonus paid. Lose €12,000+ directly.

Solution: Wait for pre-approval before signing contractor agreement.

❌ Pitfall 2: Apply for Topup Social when you’re not eligible If income exceeds €120,000, Topup Social will be refused. Time wasted.

Solution: Check yourself with authorities before applying.

❌ Pitfall 3: Mix eligible and non-eligible works without separation Example: Invoice painting (eligible 3% VAT) + furniture (non-eligible) on same line.

Result: Authorities may refuse 3% VAT on everything.

Solution: Two separate invoices or very clear net/VAT separation.

❌ Pitfall 4: Forget municipal grant (easy money often overlooked) Many municipalities offer €1,000-2,000. But you must submit application to town hall.

Solution: After works, immediately submit application to your municipality (3-6 month deadline often).

❌ Pitfall 5: Exceed €50,000 annual 3% VAT cap If you exceed €50,000 per year, you lose 3% VAT beyond that threshold.

Solution: Plan renovation across 2 years if budget exceeds €50,000.

Checklist: Before signing your project

• Verify construction year (building over 20 years?)
• Verify income (Topup Social if under €120,000?)
• Check with my municipality (grants available?)
• Request 2-3 detailed quotations (3% VAT, works separated)
• Prepare Klimabonus application (quotations + technical docs)
• Submit Klimabonus BEFORE works start
• Wait for pre-approval (10-15 days)
• Sign contractor agreement after pre-approval
• Keep invoices, photos, all documentation
• Finalise Klimabonus after works (10 days)
• Apply for municipal grant (3-6 months after)

Conclusion: €46,000 in grants don’t happen by accident

Combining grants requires planning. But the financial benefit is enormous:

€80,000 renovation becomes €33,600 after grants = 58% savings

Each forgotten grant = thousands of euros lost.

The three grants you must NEVER miss:

1. Klimabonus (up to €46,000)
2. 3% VAT (up to €8,400 on large budgets)
3. Municipal grant (€500-2,000 easy, but you must apply)

Topup Social and Enoprimes are bonuses if you qualify, but the three above are nearly universal.

Ready to optimise your renovation? Find an experienced contractor with grants expertise on tack.lu and launch your project without financial stress.