Collective DPE and energy audit: what determines the operability of an investment building (immeuble de rapport)

A Haussmann-style investment building (immeuble de rapport) rated F is bought today at a discount. That discount is not a gain: it is the present value of a programme of works that the buyer will have to fund, have voted through, and endure in the letting timetable. Since 1 January 2026, the collective energy performance diagnostic (diagnostic de performance énergétique, DPE) obligation has covered almost the whole of the collective residential stock built before 2013, and every unit rated G has been excluded from the unfurnished rental market since 1 January 2025. This guide addresses a single question: how to read a building's energy diagnostics not as a pre-contractual formality, but as the document that determines the operability of the asset over ten years, the lettability of each unit, and its exit price.

Three energy diagnostics, three regimes not to be confused

Confusion between the collective DPE, the regulatory energy audit and the engineering audit is the first source of error in acquisition files. The three documents have neither the same legal basis, nor the same debtor, nor the same legal consequences.

The collective DPE under Article L. 126-31 of the French Construction and Housing Code

Law No. 2021-1104 of 22 August 2021 on combating climate change and strengthening resilience to its effects, known as the Climate and Resilience Law, created in Article L. 126-31 of the French Construction and Housing Code (code de la construction et de l'habitation, CCH) an obligation to carry out an energy performance diagnostic at building level. The scope is that of collective residential buildings for which the building permit application was filed before 1 January 2013. The building DPE is valid for ten years and must be renewed or updated on expiry of that period, unless works justify an earlier update.

In co-ownership (copropriété), the obligation translates into a governance mechanism: the property manager (syndic) places on the agenda of the general meeting the decision to carry out the diagnostic, and then presents its results. Article 24-4 of Law No. 65-557 of 10 July 1965 then requires the question of an energy-saving works plan or of an energy performance contract (contrat de performance énergétique, CPE) to be placed on the agenda of the following meeting. In other words, the collective DPE is not an inert document: it triggers an obligation to deliberate on energy capex. An investor acquiring a unit in a co-ownership that has just received its diagnostic is buying a general meeting that is about to vote.

An Order of 20 July 2023 has also opened the possibility, subject to conditions of homogeneity of the dwellings, of generating individual DPEs from the diagnostic carried out at building level. This point is strategic: in a homogeneous building, the collective rating spreads to the units, and with it the ban on letting.

The regulatory energy audit: the regime specific to a building held in single ownership

Article L. 126-28-1 of the CCH, also resulting from the Climate and Resilience Law, requires an energy audit on the sale of single-family houses and of residential buildings comprising several dwellings but belonging to a single owner. Co-ownership units are excluded. The timetable depends on the energy rating: from 1 April 2023 for properties rated F or G, from 1 January 2025 for class E, and from 1 January 2034 for class D. Decree No. 2022-780 of 4 May 2022 sets its content.

The practical consequence is stark for the investor in investment buildings. Selling a whole building rated E, F or G requires giving the buyer, from the preliminary agreement stage, a document that quantifies one or more works scenarios, details the expected gains by stage and estimates the costs. This audit becomes the buyer's basis for negotiation. A seller who discovers it three weeks before signing negotiates on the defensive. A seller who has anticipated it, who has had an adversarial study carried out and who has secured contractors' quotations, negotiates on its own figures.

The engineering audit, a condition for access to grants and to the energy performance contract

The third document is not a mandatory diagnostic but a decision-making tool, often required as a condition for granting collective renovation grants. It is distinct from the former co-ownership energy audit that Decree No. 2012-111 of 27 January 2012 required of co-ownerships of fifty units or more equipped with a collective heating installation, a regime now absorbed by the collective DPE. The co-ownership energy audit in this contemporary sense serves to build a works programme achieving the minimum energy gain required by the grant rules, to choose between step-by-step renovation and whole-building renovation, and to structure a possible CPE. It is this document, and not the collective DPE, that makes it possible to quantify a share of the works seriously.

The statutory timetable read as a decision timetable

The statutory deadlines are not administrative compliance dates. Each one opens or closes a negotiating window.

The collective DPE obligation came into force in descending stages according to the size of the co-ownership: first developments of more than two hundred units, then those of fifty-one to two hundred units, and finally co-ownerships of up to fifty units. The small Parisian co-ownership of fifteen units, long off the radar, is now within scope. For the buyer, three situations must be distinguished:

• the co-ownership has had its building DPE carried out and has presented it to the general meeting: the rating is known, the debate on works is open, and the risk is identifiable and quantifiable;
• the co-ownership has voted to carry out the diagnostic without yet having received it: the buyer is buying an uncertainty over a horizon of a few months, with a risk of discovering an F or G rating after signing;
• the co-ownership has voted nothing: the buyer inherits a default, its catching up, and the full sequence of DPE, then the Article 24-4 deliberation, then a vote on works.

This chronology must be overlaid on that of the letting bans. Article L. 173-2 of the CCH, supplemented by Article 6 of Law No. 89-462 of 6 July 1989 and Decree No. 2021-19 of 11 January 2021, phases the exit from the rental stock: dwellings consuming more than 450 kWh/m²/year of final energy since 1 January 2023, class G since 1 January 2025, class F on 1 January 2028, class E on 1 January 2034. A building rated F acquired today therefore has a short horizon in which to bring its units out of the prohibited zone, bearing in mind that a whole-envelope renovation in co-ownership requires a vote, a works supervisor (maître d'œuvre), calls for funds and a building site.

A third timetable to take into account is that of the validity of diagnostics. DPEs drawn up between 1 January 2018 and 30 June 2021 ceased to be valid on 31 December 2024. A sale file that produces a rating from an old diagnostic produces nothing enforceable. In addition, the Order of 25 March 2024, applicable since 1 July 2024, adjusted the calculation method for dwellings of less than forty square metres. In a Parisian building containing studios and former maids' rooms, that modification alone may have moved units from one class to another. Dating each diagnostic is a first-level due diligence step.

What the buyer really inherits: the chain of voted capex

The most costly error is to treat the energy rating as a technical datum and the share of the works as an adjustment variable for the price. In co-ownership, the two are legally linked by the decisions of the general meeting.

Decisions already voted are enforceable

A general meeting resolution not challenged within the two-month period from its notification, provided for in Article 42, paragraph 2, of the Law of 10 July 1965, becomes final. The buyer of a unit cannot call into question an insulation works programme voted eighteen months before the sale on the ground that it considers it disproportionate. It can only discuss the apportionment, the performance or the formal regularity of the calls for funds. Due diligence therefore concerns the works already decided rather than future works, including those voted in the form of a mandate given to the co-ownership council or a budget envelope.

To this is added the decision-making dynamic. The Climate and Resilience Law lightened the majorities applicable to energy-saving works affecting the common parts, which are now essentially subject to the majority of Article 24 of the 1965 Law, that is, the majority of the votes cast. An investor holding a minority of the ownership shares (tantièmes) has no blocking capacity over an energy renovation programme. Buying in a co-ownership where a majority bloc is owner-occupier and eligible for grants, when the investor is not, means accepting that the energy capex will be decided by co-owners whose economic equation differs from its own.

Who pays what: the due date, not the date of sale

Article 6-2 of Decree No. 67-223 of 17 March 1967 attaches responsibility for calls for funds to their due date. The seller remains liable for the advances falling due before the transfer; the buyer bears those falling due afterwards, even where the works were voted before its entry into the co-ownership. Contrary agreements between seller and buyer, frequent in deeds, are not enforceable against the co-ownership association (syndicat des copropriétaires): they are settled between the parties, and they require the clause to be drafted precisely, supported by a schedule of calls for funds.

A second valuation point that is often neglected: the works fund established by Article 14-2-1 of the Law of 10 July 1965 is attached to the unit and is not reimbursed to the seller. Its minimum annual contribution is set by reference to the amount of the works provided for in the draft multi-year works plan and to the forecast budget. A co-ownership that has built up a significant fund is worth more, at an identical rating, than a co-ownership that has refused to feed its own. The share of the fund attached to the unit is among the information to be given to the buyer under Article L. 721-2 of the CCH, alongside the collective DPE and the draft multi-year works plan.

The combination is as follows: the collective DPE gives the rating, the draft multi-year works plan sequences and costs the interventions over ten years, the works fund pre-finances a fraction of them, and the engineering audit determines whether the programme reaches the energy gain threshold giving entitlement to collective grants. Reading only one of these four documents tells you nothing.

Lettability of the unit: from rent freeze to letting ban

The operability of an investment building is not measured by its average rating but by the lettability of each unit, rent by rent.

Since 24 August 2022, under the Climate and Resilience Law, rents of dwellings rated F or G can no longer be increased, either by revision during the lease or on re-letting. For a building held as a whole, this means a freeze of nominal rental income on part of the stock, while charges and local taxation rise. Since 1 January 2025, dwellings rated G no longer satisfy the energy decency criterion: they can no longer be the subject of a new lease, nor of a renewal, nor of a tacit renewal on regular terms. The sitting tenant may apply to the court to obtain the carrying out of works or a rent reduction.

Law No. 2024-322 of 9 April 2024 on accelerating and simplifying the renovation of dilapidated housing adjusted the situation of the co-owner landlord whose compliance depends on works to the common parts requiring a decision of the general meeting. These flexibilities require established diligence: requests for inclusion on the agenda, votes sought, formal notices to the property manager. They do not cover the passive landlord. Preserving evidence of this diligence, year after year, is part of managing the asset.

A third dimension, decisive in Paris: tourist furnished lettings. Law No. 2024-1039 of 19 November 2024 aimed at strengthening the tools for regulating tourist furnished lettings has progressively aligned this segment with the energy decency requirements, in particular by making authorisation of a change of use in the municipalities concerned conditional on a minimum performance level. The choice between unfurnished letting, long-term furnished letting and tourist furnished letting can therefore no longer be made on the stated yield alone or on tax treatment alone. The unit's rating conditions access to the operating regime. Registration, change of use and the co-ownership constraints specific to this mode of operation are dealt with in our article on tourist furnished lettings.

Mixed-use buildings: the second regime, that of the tertiary sector

An investment building with shops on the ground floor or office floors may fall simultaneously under two sets of regulations. Decree No. 2019-771 of 23 July 2019, codified in Articles R. 174-22 et seq. of the CCH, requires buildings housing tertiary-sector activities over a cumulative floor area of at least one thousand square metres to reduce final energy consumption by 40% in 2030, 50% in 2040 and 60% in 2050 against a reference year, with an annual declaration on the OPERAT platform.

Two consequences for the landlord. First, the obligation falls jointly on the owner and the tenant, which requires the allocation of works and the transmission of consumption data to be dealt with in the lease, by a properly drafted environmental appendix (annexe environnementale). Second, a shop or office whose operator cannot demonstrate its reduction trajectory becomes a less liquid asset, regardless of its headline rent. The operability of the asset in a mixed-use building is determined under both regimes at once. The allocation of these obligations between landlord and tenant is dealt with separately in our article on the DPE and the tertiary-sector decree in commercial leases.

Structuring energy due diligence before committing to a price

The aim of the pre-contractual phase is not to collect documents but to reconstruct the building's trajectory and its cost.

The documents to require and to date, beyond the minimum list in Article L. 721-2 of the CCH:

• the collective DPE, with its date, its author and the methodological order applicable at the time it was carried out;
• the minutes of the last three general meetings, read resolution by resolution, including rejected resolutions, which reveal deadlocks;
• the draft multi-year works plan and, if there is one, the engineering audit and the scenario chosen;
• the signed works contracts, the quotations voted and the forecast schedule of calls for funds;
• the statement of unpaid charges and the association's cash position, which determine the real capacity to fund a programme;
• for a building in single ownership, the energy audit under Article L. 126-28-1 of the CCH and any structural diagnostics;
• the current leases with their rating unit by unit, the expiry dates and the rent review clauses.

On the contractual side, three levers deserve to be systematised. First, a condition precedent relating not to the obtaining of financing but to the content of the collective DPE or the audit, where they are not yet available at the preliminary agreement stage. Second, a clause allocating calls for funds tied to the actual schedule, and not solely to the signing date, with a fraction of the price held in escrow up to the share of the works voted. Third, a statement by the seller that there is no resolution voted and not yet called and no pending proceedings affecting the building, accompanied by a property liabilities warranty (garantie de passif) limited in amount and duration.

When the diagnostic is wrong or the co-ownership is inert

The DPE is no longer a purely informative document. Since 1 July 2021, it has been enforceable against the person who provides it. A buyer or tenant who shows that the rating provided was wrong has a claim: contractual liability of the diagnostician, whose insurance must be checked, and where appropriate a claim against the seller or landlord. The courts classically compensate the loss resulting from the impossibility of negotiating the price with full knowledge, as well as the cost of the works made necessary. The difficulty is one of evidence: it is prepared before the dispute.

Where the rating is contested or the extent of the thermal defects is disputed, summary proceedings for an expert appointment (référé-expertise) under Article 145 of the French Code of Civil Procedure remain the most effective tool. It makes it possible to have a court-appointed expert designated before any trial, to record the condition of the building on an adversarial basis, and to fix responsibilities between the diagnostician, the works supervisor and the contractors. Started early, it transforms a commercial balance of power. Started late, it merely documents a loss.

Faced with a co-ownership that refuses to deliberate or whose property manager does not place on the agenda the questions required by Article 24-4 of the 1965 Law, the route is twofold: the formal request for inclusion, then a liability action against the property manager, or even a court challenge to the general meeting within the two-month period of Article 42. The tools specific to co-ownerships in difficulty, ad hoc mandate (mandat ad hoc) and interim administration (administration provisoire), follow a different logic and a different threshold of deterioration. On these tools and on the division provided for by Article 28, see our analysis of getting out of the deadlock of a degraded asset by division or interim administration.

Conclusion: the energy diagnostic is a valuation document, not an appendix

The defensible position is as follows: in 2026, the energy rating of an investment building no longer corrects the price at the margin, it determines the lettable perimeter that can be operated and the liquidity of the asset on resale. A building rated F whose co-ownership has voted a funded programme, documented by an audit and pre-financed by a substantial works fund, is worth more than a building rated E whose general meeting has never ruled, because the first has a timetable and the second an uncertainty.

Two operational recommendations. Before signing a preliminary agreement, have the complete chain reconstructed: collective DPE, Article 24-4 deliberation, draft multi-year works plan and calls for funds voted, and cost the share of the works on a high assumption, without grants, then make the trade-off. And never buy a building in single ownership rated E, F or G without having had the energy audit provided by the seller counter-checked: this document is the foundation of the price negotiation, and it is the one that will be set against the next seller, that is, against you.

Frequently asked questions

Is a co-ownership of fewer than fifty units subject to the collective DPE obligation? Yes. The entry-into-force timetable of Article L. 126-31 of the CCH, resulting from Law No. 2021-1104 of 22 August 2021, proceeded in descending stages: more than two hundred units, then fifty-one to two hundred units, then co-ownerships of up to fifty units, for which the obligation has been effective since 1 January 2026. The scope criterion remains the filing of the building permit application before 1 January 2013. The small older co-ownership, very common in Paris, is therefore fully concerned.

Does the collective DPE dispense with the individual DPE for selling or letting a unit? In principle no: the building-level diagnostic and the dwelling diagnostic meet distinct obligations. An Order of 20 July 2023 has nevertheless opened the possibility, where the dwellings have homogeneous characteristics and subject to the conditions it lays down, of generating individual DPEs from the building DPE. In that case, the collective rating is passed directly on to the units, with the attendant consequences for lettability.

Must an investment building held by a single company produce an energy audit to be sold as a whole? Yes, if its rating places it within the scope of Article L. 126-28-1 of the CCH: classes F and G since 1 April 2023, class E since 1 January 2025, class D from 1 January 2034. This audit, the content of which is regulated by Decree No. 2022-780 of 4 May 2022, must present quantified works scenarios and be provided from the preliminary agreement stage. Co-ownership units do not fall under this regime.

Who bears the cost of energy renovation works voted before the sale of a unit is signed? Article 6-2 of Decree No. 67-223 of 17 March 1967 makes liability depend on the due date of the calls for funds: the seller pays those falling due before the transfer, the buyer those falling due afterwards, including for works decided earlier. Any contrary agreement is settled between the parties and is not enforceable against the co-ownership association. It is useful only if it is tied to the actual schedule of calls for funds, ideally with an escrow.

Can a dwelling rated G still be let? Not under a new residential lease for use as a main residence: since 1 January 2025, the energy decency criterion of Article 6 of the Law of 6 July 1989 excludes class G, following the exclusion on 1 January 2023 of dwellings consuming more than 450 kWh/m²/year of final energy. Class F will follow on 1 January 2028 and class E on 1 January 2034. Existing leases are not cancelled, but the tenant may take action to obtain works or a rent reduction.

What remedies are available where the DPE provided on acquisition proves to be wrong? The DPE has been enforceable since 1 July 2021. The buyer may seek the contractual liability of the diagnostician, after checking its certification and insurance, and where appropriate that of the seller. Evidence is built through summary proceedings for an expert appointment (référé-expertise) based on Article 145 of the French Code of Civil Procedure, begun before any proceedings on the merits, to establish on an adversarial basis the real condition of the property and the cost of bringing it up to standard.

Does a mixed-use building of residential units and shops fall within the tertiary-sector energy-saving scheme? Yes, where the cumulative floor area of tertiary activities in the building reaches one thousand square metres, within the meaning of Decree No. 2019-771 of 23 July 2019 and Articles R. 174-22 et seq. of the CCH. The reduction targets are 40% in 2030, 50% in 2040 and 60% in 2050, with an annual declaration on the OPERAT platform. As the obligation is shared between landlord and tenant, the allocation of works and the transmission of consumption data must be dealt with in the lease's environmental appendix.