Window Klimabonus: prepare the application and check the rate
Published on 31 July 2026 · Verified on 18 September 2026 · The Mestravaux.lu team
Window replacement may qualify under Klimabonus 2026 conditions. Pane count or an eligible label is insufficient. Prepare the application before work and confirm the regime matching your circumstances.
The essentials in 30 seconds
- Check the building and number of renovated elements.
- Assess glazing and the wall or ventilation.
- Separate prior approval, applicable rate and payment.
Identify the route
Guichet distinguishes renovation with advice and a single-element route. The latter requires an approved contractor or suitable accompaniment; multiple elements require advice. The regime covers, in particular, Luxembourg homes over 10 years from building permission.
| Point | Repère officiel 2026 | Document à demander |
|---|---|---|
| Bâtiment | plus de 10 ans selon le régime | date de l'autorisation de bâtir |
| Vitrage | Ug ≤ 0,6 W/(m²K) | fiche technique du vitrage |
| Humidité | mur/toiture conforme ou VMC | preuve du mur ou de la ventilation |
| Aide spécifique | 70 €/m² annoncé | surface assainie et offre détaillée |
Résumé éditorial des pages Guichet.lu consultées le 4 août 2026. La procédure officielle prévaut.
Have technical suitability checked
For windows and French doors, the advice-route page specifies Ug ≤ 0.6 W/(m²K). It also requires the exterior wall or heated-attic roof condition, U ≤ 0.85 W/(m²K), or controlled mechanical ventilation. Assess these criteria together.
Read the rate with its dates
The rate is 70 €/m² renovated, increased to 80 €/m² for approval-in-principle applications submitted from 1 January 2026 to 30 June 2027 inclusive and invoices issued by 31 December 2030. Area and other conditions still need validation.
Your project deserves an accurate estimate — it's free.
Request a quoteSeparate before and after work
Official pages require approval in principle before work and a payment request after completion. Assemble the selected route’s forms and evidence. Assign each document and timing rather than waiting for the final invoice to start procedures.
Prepare actual financing
Request estimates showing area, rate and assumptions. Check any municipal support directly. Prefinancing announced from 1 January 2027 is optional and conditional; do not treat it as an automatic discount available today or from every contractor.
Related guides to continue
- Ug, Uf and Uw: read window thermal performanceA thermal value helps only when its scope is known. Glazing alone and a complete window are different objects. Request the symbol, unit, product and conditions behind each figure.Read the guide
- Double or triple glazing: compare variants for your homePane count alone cannot select a window. Request identified variants and compare performance and cost within the same project. No average premium or payback is claimed without verifiable offers.Read the guide
- New windows: plan air renewalWindow replacement is a time to check how air enters and leaves the home. This does not depend on a minimum window count. Check before choosing air inlets and trims.Read the guide
- Understand a window quote: product, work and exclusionsFirst check whether offers describe the same openings and finished result. This guide provides a comparison method, not average prices or a legal contract template.Read the guide
Frequently asked questions
Is triple glazing sufficient?
No. Confirm specifications, building, process and evidence.
Can I use an old grant guide?
Check applicable regime and project dates. Earlier rules do not automatically govern a current application.
Does support cover the entire quote?
Do not assume so. Separate spending, eligible area, calculated grant and remaining funding.
Where can I confirm my case?
With the Guichet unique des aides au logement and approved project adviser; official pages below provide contacts and forms.
Take action
Your project deserves an accurate estimate — it's free.
Request a quote