In co-ownership, energy renovation seemed to have become essential. With the Collective DPETHE multi-year work plan and progressive rental bans, regulatory pressure was pushing to act quickly. But a new bill presented on April 23, 2026 partially reshuffles the cards. The government wishes to authorize the re-rental of housing classified F or Gprovided that the owner undertakes to carry out work. A relaxation intended to respond to the housing shortage but which could encourage certain co-owners to procrastinate. Verdict this summer when the bill will go before the deputies.
In the meantime, at Foncia, one of the main co-ownership managers in France, the process is underway. “The dynamic is established”summarizes Corina Osadciuc-Mahé, energy renovation manager. However, she specifies: “ The co-ownerships which vote on work today are often those which started working on the subject well before. » Because a global energy renovation project prepares for a long time in advancet, with diagnoses, studies, the financial package then the vote at the general meeting. The figures put forward by Foncia give the measure of the movement: after having committed in 2022 to renovating 300 condominiums in three years, the group says it has exceeded this objective with more than 400 condominiums having voted for an energy renovation. In 2025, around 11,000 housing units would have voted for work and 14,000 housing units the study phase, i.e. 25,000 homes already engaged in the dynamic according to the company.
Energy renovation of co-ownership: here is the real calculation to do before the AGM
For Corina Osadciuc-Mahé, the reasoning to be followed before the AGM is simple in principle, even if it is often poorly stated: you have to start from the total amount of the work, subtract all the aid that can be mobilized, then measure the remainder to be paid and its financing. Only then must compare this cost to what inaction can cause a loss in the value of the property.
She cites a very telling order of magnitude: “On an average condominium, 30-40 lots, we can have work worth a million euros. » An amount that is often frightening at first glance. But this million is not the final cost paid in cash by the co-owners.
Today, MaPrimeRénov’ Copropriété assistance can finance 30% to 45% of the cost of the work, with a ceiling of 25,000 euros per accommodation, on condition in particular of achieving a minimum energy gain of 35%. The aid can be combined with CEE, community aid and eco-PTZ co-ownership.
In the example given by the manager of Foncia, a project 1 million euros can thus benefit from 300,000 to 400,000 euros in aid, sometimes more with the local contribution. The rest is not necessarily supported immediately. Part can be financed by eco-PTZ and the balance by a collective loan with individual membership, or by own funds.
How much can energy renovation cost you depending on your lot?
Hypothesis: co-ownership of 30 lots, overall works costing €1,000,000
1. Gross distribution by co-owner
- €1,000,000 ÷ 30 lots = ≈ €33,300 per lot
2. Deduction of aid (realistic case)
- MaPrimeRénov’ Co-ownership + CEE + local aid (approximately 30% to 45% aid)
Remains after aids:
- between €18,000 and €23,000 per lot
3. Individual aid (depending on income)
- Until €1,500 to €3,000 additional for low-income households
New remaining charge:
- between €15,000 and €21,500
4. Financing (eco-PTZ + collective loan)
Example over 15 years:
- €15,000 → ≈ €90/month
- €20,000 → ≈ €120/month
5. To put in front: the gains
Energy savings:
- until 30% to 50% on the heating bill
Valuation of the property:
- several % increase on resale according to the DPE
Doing the work “by gesture” is often the wrong calculation
This is one of the most common mistakes. Many co-owners want to break up the work to smooth out the expense: first the renovation, then the heating, then the insulation. Except that this logic may cost more in the end. “ At Foncia, we favor a global approach to energy renovationrather than an intervention by gesture »insists Corina Osadciuc-Mahé. His argument is twofold. First, a renovation alone generally does not make it possible to achieve the 35% energy gains necessary to trigger the basic aid from MaPrimeRénov’ Copropriété. Then, changing the heating in a poorly insulated building is like heating a sieve.
The discount on strainers is no longer theoretical
The other part of the financial calculation is patrimonial. The Notaries of France note that the energy label weighs more and more on transactions and that the energy-intensive housing suffers an increasing discountwhile better classified properties are valued more. Corina Osadciuc-Mahé also relies on this market reality: “We can see that goods, depending on the energy label, sell better or worse. » For a co-owner lessor, the challenge is twofold: regulatory risk on medium-term rental and weakening of the resale value. For an occupant, it is also a question of the future liquidity of the property. Clearly, the correct calculation is not only: How much does the work cost me? He is also: How much does the lack of work cost me?
The key role of the audit and the financing plan
Legally, the energy audit is not the obligatory tool in co-ownership; it is the collective DPE which is gradually implemented according to the size of the co-ownership, and the draft multi-year work plan (PPPT) for buildings over 15 years old for residential use. But in practice, the audit is often essential to obtain certain local aid and promote the EWCs. “The energy audit is not obligatory… however, it is strongly recommended »summarizes Corina Osadciuc-Mahé. For what ? Because it allows you to detail the scenarios, quantify the gains and above all build a real financing plan. This must integrate collective aid, individual aid according to income, EECs, possible local contributions and financing solutions for the remainder.
On this point, the manager of Foncia insists on pedagogy: “We must not wait for the general meeting” to discover a gross cost and quotes. It’s necessary a preparatory meetingexplanations, a readable scenario and transparent pricing. Without this, the vote almost always ends on the same reflex: fear of the amount.











