How to Vet a Paris Apartment Before You Buy (Diagnostics, Building Condition & Loi Carrez)

Before you make an offer on a Paris apartment, French law requires the seller to provide eight mandatory diagnostic reports, and you should independently review the building’s co-ownership finances and condition. Together, these tell you the property’s real surface area, any structural or safety risks, and whether the building itself is financially and physically sound. Here’s exactly what to check and why each one matters.

The 8 Mandatory Diagnostic Reports

French law requires sellers to complete these tests before listing, and to hand the results to buyers before signing the preliminary contract:

Diagnostic	What it covers
Loi Carrez	Precisely measured surface area of the property
Lead (plomb)	Presence of lead paint or materials, mainly relevant in pre-1949 buildings
Asbestos (amiante)	Presence of asbestos, relevant in buildings constructed before July 1997
Termites	Presence of termite activity, required in certain designated zones
Electrical installation	Condition and safety of the property’s electrical system
Gas installation	Condition and safety of any gas installation
Energy Performance Rating (DPE)	Energy consumption and emissions, graded A to G
Natural and environmental risk	Exposure to flood zones or other designated risk areas

These reports give you recourse if a result later proves inaccurate, but the seller isn’t obligated to fix anything the tests reveal. It’s important to thoroughly understand these tests to make an informed purchase decision. Buyers can opt at their expense for a property inspection, although these are not common on Paris apartment sales. Buyers will also want to consider renovation, restoration and repair costs when setting their offer price.  

What Is the Loi Carrez, and Why Does It Matter So Much?

What is the loi Carrez?

The loi Carrez is a French law requiring sellers to state a property’s exact surface area, measured according to a specific legal method that excludes areas with ceilings under 1.8 meters, along with stairwells, garages, and cellars. It applies to any sale of a unit within a co-owned building (an apartment, essentially any Paris purchase).

Why it matters more than it sounds like it should

Unlike a casual square-footage estimate, the loi Carrez measurement has real legal weight. If the stated surface area in the final deed turns out to be more than 5% smaller than what was measured, the buyer can seek a price reduction proportional to the shortfall, within one year of the signing. This is a genuinely useful protection, but only if you actually check the number against the measurement report rather than taking the listing’s stated size at face value. Note that this only applies to lots in a copropriété (condo-style ownership) – not to houses sold outright.

What does carrez mean in practice for a buyer?

Ask for the loi Carrez certificate before you offer, not after. Compare it to the listed square meterage. A small discrepancy is normal (the 5% tolerance exists for a reason), but a larger gap is worth raising before you’re under contract, when you still have full negotiating leverage.

Vetting the Building, Not Just the Apartment

The diagnostics above cover the unit itself. The building’s overall condition and finances are a separate, and just as important, layer of due diligence, one that isn’t legally mandated the same way but is arguably more likely to affect your long-term costs.

Co-ownership meeting minutes (last 3 years)

Every co-owned building holds an annual general assembly (assemblée générale) where major decisions get voted on: planned renovations, special assessments, disputes between owners, and the building’s overall financial health. Reviewing the last three years of minutes tells you whether a major (and expensive) renovation is already voted and scheduled, since that cost typically falls on whoever owns the unit when the work is billed, not necessarily the seller. This is the default rule absent agreement. Buyer and seller can negotiate a different allocation in the promesse and acte de vente, but that arrangement only binds the two parties to each other. It’s not opposable to the syndic, who will still send the appel de fonds to whoever is the titled owner at exigibilité, and the parties would need to settle up between themselves per their private agreement.

Building regulations (règlement de copropriété)

This document governs what you can and can’t do with the unit: whether short-term rentals are permitted, whether you can renovate structurally, and how shared costs are allocated between units. Worth reading before you offer, not after you’ve committed.

Building management company and fees

Confirm who manages the building (the syndic), what the current monthly charges de copropriété are, and whether there’s a history of missed payments or disputes among other owners, since unpaid charges from other unit owners can sometimes affect the building’s overall financial stability.

Building condition itself

Look past the apartment’s own finish and check the building: the state of the stairwell, elevator (if any), the façade, and the roof. A beautifully renovated apartment inside a building with a crumbling façade or elevator that’s been “temporarily out of service” for two years is a real and common surprise, and it’s a signal the co-ownership may be underfunded or slow to act on maintenance.

What Renovation Scope to Expect

Many Paris apartments, particularly in older buildings, need some degree of renovation, from cosmetic updates to full structural work. A few things worth checking specifically:

• Plumbing placement: older Haussmannian buildings sometimes have structural or plumbing constraints that limit where a bathroom or kitchen can be added or moved, worth confirming with a contractor before assuming a layout change is possible
• Air conditioning: mini-split systems can now be installed in many Paris apartments, but co-ownership rules may govern where exterior units can be placed, worth checking the building regulations. If there is no room to conceal an air handler above a false ceiling, we recommend building a wall mounted minisplit it into custom cabinetry. 

Frequently Asked Questions

What is the loi Carrez?

• A French law requiring sellers to disclose a property’s precisely measured surface area before sale. If the actual measurement is later found to be more than 5% smaller than stated in the purchase contract, buyers can seek a proportional price reduction within one year of signing.

What diagnostics are sellers required to provide in France?

• Eight reports: loi Carrez surface measurement, lead, asbestos, termites, electrical installation, gas installation, energy performance rating (DPE), and natural/environmental risk exposure.

Is the seller required to fix issues found in the diagnostic reports?

• No. The reports create a paper trail and give buyers grounds for recourse if results later prove inaccurate, but there’s no obligation for the seller to repair anything the tests reveal. Any repairs are a negotiation point, not a requirement.

How do I check a building’s financial health before buying?

• Request the last three years of co-ownership general assembly minutes, the current règlement de copropriété, and details on the building management company and current charges. Look specifically for any voted-but-unfunded major works and a history of missed payments from other owners.

Can I get a price reduction if the apartment is smaller than listed?

• Yes, if the loi Carrez measurement is later found to be more than 5% smaller than what was represented in the purchase contract, buyers can seek a proportional price reduction, but only within one year of the signing date.

---

Vetting a Paris apartment properly means looking well past the finishes, at the legal surface measurement, the building’s finances, and its physical condition, all before you’re under contract. For the full purchase process these checks fit into, see French Purchase Process: Step by Step. Learn more about working with Miranda, or see our full buyer’s agent services.

Contact with Paris Property Group to learn more about buying a property in Paris.