Real Estate Diagnostics: obligations, audits, and market impact

In France, real estate transactions are governed by a strict legal framework where transparency has become paramount.

Since the implementation of the Climate and Resilience Law, technical diagnostics are no longer mere administrative formalities—they have become critical levers in financial negotiations.

What is a real estate diagnostic?

A diagnostic is a technical expertise carried out by a certified, independent professional. These reports inform the buyer about the "health" of the property. Important: Since July 2021, the DPE (Energy Performance Certificate) has become legally enforceable (opposable). This means a seller can be held liable if the energy rating is found to be inaccurate.

List of mandatory sales diagnostics

The requirements vary based on the age of the property and its location. Below are the essentials:

• DPE (Energy Performance Certificate): Mandatory for all properties (except off-plan/VEFA). It ranks the property from A to G.
• Mandatory Energy Audit (New): Essential for the sale of standalone houses or single-owner buildings ranked F, G, and now E. It provides detailed renovation scenarios to reach a B rating.
• Asbestos: For properties with a building permit issued before July 1997.
• Lead (CREP): For residential properties built before January 1, 1949.
• Electricity & Gas: For installations older than 15 years.
• Loi Carrez: Mandatory only for co-ownership lots (copropriété), certifying the floor area.
• ERP (State of Risks and Pollution): Must now be presented at the very first viewing of the property.
• Termites / Dry Rot: Required in specific zones designated by prefectural decrees.
• Housing Information Logbook (CIL): For new builds or properties that have undergone significant energy renovations since 2023.

The impact of the DPE on the real estate market

The market has split into two distinct categories: "energy-efficient" homes and "energy sinks" (passoires thermiques).

1. "Green Value" and price depreciation

Today, a poor DPE rating is more than just a negotiation point; it is a factor in real capital depreciation. For properties rated F or G, we observe price drops ranging from 15% to 25% compared to similar properties rated A or B. This discount reflects the estimated cost of renovations required to meet modern standards.

2. The rental ban calendar

The impact on prices is intensified by the pressure on buy-to-let investors:

• Since January 1, 2025: Properties rated G are banned from the rental market.
• From January 1, 2028: The ban will extend to properties rated F. This regulation has led many investors to sell their energy-inefficient assets, increasing supply and putting downward pressure on prices for these specific goods.

3. Should you renovate before selling?

Contrary to the trends of 2022, the strategy has shifted. With the increase in government grants and the growing scrutiny of buyers, a targeted renovation (insulation, heat pumps, etc.) often preserves the asking price and triggers a "love at first sight" reaction that is nearly impossible for an unrenovated "energy sink."

The importance of professional guidance

With regulations becoming increasingly complex, ranging from the enforceability of the DPE to mandatory audits, any error can be costly or block a sale at the notary stage.

A listing that displays a clear DPE and a complete diagnostic file immediately reassures the buyer and limits their grounds for negotiation.

Expert Advice: Do not wait until the last minute to perform your diagnostics. An ERP must be available from the first listing, and an Energy Audit should be ready before the first viewings to justify your asking price.

To secure your transaction and enhance the value of your heritage on the French Riviera, trust the expertise of Côte d’Azur Sotheby’s International Realty.

Contact us for a precise valuation: info@cotedazur-sothebysrealty.com