The French Property Diagnostic Report: Your Wake-Up Call Before You Buy

In recent years, the French property market has seen some big shake-ups—especially when it comes to how homes are monitored, assessed, and ultimately, valued. At the centre of it all? Energy efficiency.

And that’s where the diagnostic report—le dossier de diagnostic technique (DDT)—steps in. This is not just a boring bit of paperwork to tick off. It's basically the property's technical passport and your first serious reality check.

📂 What is a Diagnostic Report in France?

Every property listed for sale must have a diagnostic report, and it’s the vendor’s legal responsibility to provide it. This dossier de diagnostic technique (DDT) includes several key assessments, such as:

• DPE (Diagnostic de Performance Énergétique) – Energy efficiency rating (from A to G)
• Asbestos check (amiante)
• Lead paint report (plomb)
• Termite report (termites)
• Gas and electricity installation checks
• ERP – État des Risques et Pollutions (Environmental Risk & Pollution Report (formerly ERNMT)
• Carrez law measurement (for co-owned properties)

🚩 Important note: All properties must also be checked for the correct connection to either the mains drainage system(and issued a certificat d’assainissement collectif) or, if not connected, for the proper functioning and legal compliance of the septic tank (assainissement non collectif). This is handled by the local authorities, often through the SPANC (Service Public d’Assainissement Non Collectif), and is a separate but legally required report.

🟢⚠️ The New 2025 Rules: Energy Audits Just Got Serious

The DPE rating now carries even more weight than ever—especially as of January 1st, 2025:

• All properties rated E, F, or G will legally require a full energy audit (audit énergétique).
• This audit must be done before you can even show the property to prospective buyers.
• Not just a formality—it is now a legal obligation to present it prior to any offer or compromis signing.

And yet, many sellers are still resisting.
Too many vendors try to delay or avoid this by saying, “We’ll do it later at the compromis stage.”
No. That’s a 🚩red flag. As a buyer, you should not even consider placing an offer—and as an agent, we’re not allowed to conduct viewings—without this audit completed and available.

🗓️ Who Pays for the Diagnostics and Audit?

The vendor pays for all of it.
And yes, it can sting.

• Standard diagnostic reports: €300–€500
• Energy audit (required for E-G): €700+, often closer to €1,000 for complex or large properties

For sellers, it’s a financial and emotional hurdle—especially when it highlights just how much work (and cost) a buyer is going to face.

🔍 True Story Time:

I once listed a glorious old manoir. Picture-perfect, gorgeously decorated, impeccable gardens. You’d think it was a dream.

But the DPE rating? A lowly G.

❄️ Annual heating costs were sky-high updated heating? €€€
🚪 Windows were all bespoke French doors and arches = no standard sizes = €80K just for double glazing.
🧱 Insulation in the loft? Inadequate. Another €30K.
🌬️ Internal wall insulation? €50K+.

So while the aesthetics were worth drooling over, the practical cost of comfort was a financial gut-punch for any buyer. And the sellers? They were selling because they couldn’t afford to do the work themselves.

🧬 So, What Does This Mean for You?

👨‍🏠 If You're a Buyer:

• Always ask for the full diagnostic report up front.
• If the DPE is E or worse, expect an energy audit—and budget accordingly.
• Don't assume a charming home = energy efficient.
• And no, the seller won’t cover these upgrade costs. They’re your problem now.

🏡 If You're a Seller:

• Understand that your DPE rating affects your property value.
• It doesn’t matter if the decor is magazine-worthy. If the rating is poor, expect buyers (and their banks) to knock the price down.
• Be honest, get the right diagnostics done, and don’t try to reuse an old report from a different property. (Yes, it’s happened. Yes, we catch it.)

At Leggett Immobilier, we’re held to high standards. Each DPE report is proofed, checked, and must match the exact property listed. No shortcuts. No admin errors. We’re not taking chances—neither should you.

📘 Final Thoughts:

A lot of buyers come to France chasing the dream: character, countryside, and charm. But the diagnostic report and energy audit are where the dream meets reality. They are not there to scare you—they’re there to prepare you.

So whether you’re house-hunting with heart eyes, or nervously preparing to sell that beloved family home, remember: this report is your friend. A brutally honest one.

💬 Need help understanding yours?
They’re always in French (because of course they are), but that’s what I’m here for.
You can:

👉 Book a 1-to-1 Visio session with me
👉 Or ask up to 3 questions via email here

I’ll translate the jargon, give it to you straight, and help you see what the numbers really mean.

Let’s keep it real—and realistic. That’s what this blog’s all about.