Klimabonus 2026: preparing a renovation file in co-ownership

The Klimabonus 2026 scheme provides for specific steps for co-ownerships. Before voting on works, the co-ownership must organise the studies, the decisions, the forms and the supporting documents. This article deals with that preparation; the conditions and amounts of the aid can be consulted on the official sources.

Start with the building

An energy project starts with an assessment, not with a form. You need to understand:

• the condition of the building envelope;
• the consumption;
• the heating;
• the ventilation;
• the defects;
• the works envisaged;
• the constraints;
• the needs of the occupants.

Identify the process

Depending on the measure chosen, the process may involve:

• energy advice;
• an estimate;
• plans;
• an energy performance certificate;
• inspections;
• a review of the quotes;
• monitoring;
• a final report.

The agreement in principle before the works

Where it is required, an agreement in principle must be requested before starting the works. You should therefore not sign the orders or begin the works assuming the aid is secured: the chronology of the file matters as much as its content.

Deciding at the meeting: which majority

The works require a decision of the general meeting, with the majority corresponding to their nature, within the meaning of the Law of 16 May 1975:

• energy renovation falls under the majority of the votes of all co-owners (Article 16); failing this majority, a fresh meeting decides under Article 15;
• more substantial alterations, which do not fall under Article 16, are subject to the majority of Article 17 (members representing at least three quarters of the votes).

Preparing the resolution

The resolution passed should specify as far as possible:

• the works;
• the quotes;
• the budget;
• the financing;
• the aid application;
• the applicant;
• the signatory;
• the mandate given to the syndic;
• the bank account to receive the aid;
• the allocation of the sums received;
• the submission obligations;
• the appended documents.

Organising the documents

An aid file is prepared document by document. Depending on the measure:

• the appendix or form for collective works;
• the proxies or the minutes;
• the list of apartments;
• the energy reference floor areas, excluding common areas;
• the forms;
• the invoices;
• the proof of payment;
• the bank details;
• the reports;
• the certificates;
• the confirmation of the works.

The periods to know

The scheme operates within time windows. The periods below are indicative and must be checked against the official sources at the time of the project:

• first application for an agreement in principle: from 1^er January 2026 to 31 December 2030;
• invoices: from 1^er January 2026 to 31 December 2035;
• payment of the aid: by 31 December 2039 at the latest;
• application after works: within 4 years following 31 December of the year of the invoice.

Planning the cash flow

The aid approval and the co-ownership's cash flow are two separate things: the aid is neither immediate nor guaranteed at the time the expenditure is committed. You therefore need to anticipate:

• the deposits;
• the payment deadlines;
• the calls for funds;
• the time to receive the aid;
• the ineligible expenses;
• the discrepancies;
• the VAT;
• the fees;
• any loans.

Keeping the file

Gather and keep:

• the studies;
• the certificates;
• the plans;
• the quotes;
• the resolution;
• the contracts;
• the invoices;
• the payments;
• the applications;
• the decisions;
• the reports;
• the acceptance of works;
• the warranties.

Sources

• Guichet.lu, “Klimabonus” — official sources.
• Klima-Agence — official sources.
• Law of 16 May 1975 on the status of co-ownership of built property (majority regimes, Articles 15, 16 and 17): data.legilux.public.lu.

Last checked: 2026-07-28.

Disclaimer

The conditions, amounts and forms are liable to change. The official sources must be checked at the time of the project.