A couple finds the ideal property, signs the compromise, then discovers that the displayed energy performance diagnosis (DPE) does not reflect the actual state of insulation. The planned financing does not cover the necessary work, and the withdrawal period is running out. This frequent scenario illustrates a often underestimated point: in a real estate project, costly mistakes lie in the technical details, not in the major steps that everyone knows.
Energy audit and DPE: what changes concretely for a real estate purchase
Before discussing budget or financing, it is worthwhile to check the energy situation of the targeted property. Since January 1, 2025, the mandatory energy audit for sales also applies to homes classified as E (individual houses and buildings in single ownership), and no longer just to classes F and G.
This audit lists the recommended work in order of priority, along with an estimate of their feasibility. For a buyer, it serves as a negotiation lever on the price, but also as a tool to calibrate the overall budget even before contacting the bank.
Another point to check: the DPE of homes heated by electricity can change without work, thanks to an update of the calculation method. A property classified as F could move to E with an up-to-date certificate. One might think this is unreservedly good news, but this administrative evolution does not inform about the actual state of insulation. Therefore, it is essential to read the DPE in detail, not just the letter displayed in the window.
Specifically, during a visit, one should request the complete energy audit (not just the DPE), and note the identified work items. This information is then used to anticipate the actual costs of occupying the property, beyond the purchase price. When consulting the Angie Sweet Home site for real estate, this on-the-ground data is part of the criteria learned to integrate early in the thinking process.
Real estate financing: the pitfalls of an overly optimistic financing plan
Most buyers know how to calculate their borrowing capacity. The problem lies in what is included, and especially what is forgotten.
Not including aids without prior verification
The zero-interest loan (PTZ) has been extended to new properties in all municipalities since April 1, 2025, but it remains subject to eligibility and resource conditions. For older properties, additional criteria regarding location and work apply. Verifying the eligibility of the specific property with one’s bank before counting on the PTZ in the financing plan avoids finding oneself with a budget cut at the last moment.
The same logic applies to MaPrimeRénov’: the rules have been tightened, particularly regarding the process by gesture for several types of work, including insulation. Including these aids in the budget without confirming their availability for the specific project amounts to building a financing plan on sand.
The costs that the online simulator does not show
Mortgage loan simulators provide a monthly payment, rarely a realistic total cost. Here’s what is often forgotten:
- Notary fees, which represent a significant part of the price for older properties and vary by department
- The loan guarantee (mortgage or surety), the cost of which varies depending on the chosen organization and the amount borrowed
- Borrower’s insurance, negotiable but rarely optimized during a first purchase, even though it weighs heavily on the total duration of the loan
- The work identified by the energy audit, which should be included in the budget from the research phase
A reliable real estate budget includes all ancillary costs from the outset, not just the price of the property and the monthly loan payment.
Sale compromise and notarial deed: the checks that are overlooked under time pressure
Once the offer is accepted, the pace accelerates. The sale compromise (or promise) binds both parties, and the ten-day withdrawal period begins to run from its notification. During this window, there is a tendency to focus on financing. This is a timing error.
The checks to be prioritized during this period concern easements (right of way, urban planning constraints), the co-ownership regulations for an apartment (charges, voted works, ongoing procedures), and the consistency between the announced area and the actual measured area.
The notary verifies legal compliance, not the relevance of the purchase. Their role is to secure the transaction legally. Questions about the state of the property, the neighborhood, or nearby development projects fall under the buyer’s responsibility.
Negotiating the real estate price: using technical data as leverage
Prices are often negotiated based on feelings (“the neighborhood is noisy,” “the kitchen needs to be redone”). Sellers easily resist these subjective arguments.
Technical elements provide a stronger leverage. An energy audit classifying the property as E with identified insulation work, a general assembly report mentioning a voted but unfunded renovation, a DPE whose validity is expiring: all these objective facts justify a price revision. The gap between the displayed price and the price consistent with the actual state of the property can be quantified based on these documents.
Negotiation works better when it is based on documented expense items that the seller cannot contest, rather than on a general market downturn impression or on comparisons with neighboring listings whose details are unknown.
A successful real estate project relies less on mechanically following a checklist of steps than on the ability to identify the risk areas specific to each property. The energy audit, the verified financing plan, and the careful reading of legal documents form a stronger foundation than any general guide.
