EXPERTISE – VEFA
You’ve just taken delivery of your new-build apartment in Antibes. You pull out a tape measure and go room by room. The total comes to 68.5 m². You check the VEFA plan you signed two years ago: 71 m². 2.5 m² missing – that’s the size of a walk-in closet. What nobody tells you: in 40% of VEFA disputes, the discrepancy exceeds the legal tolerance.
What you see – and what it’s really hiding
You compare your measurements to the plan’s dimensions with a straightedge. Frankly, it looks consistent at a glance. But Carrez surface isn’t the sum of the rooms.
What I often see in this situation in Antibes: owners measure the interior walls. The Carrez law, however, requires measuring the clear floor area – that is, inside the load-bearing walls. Partition thickness, service ducts: all of it must be deducted. One owner measured 72 m². My topographic survey with a Leica TS total station revealed 69.8 m². The discrepancy came from a 25 cm-thick service duct running the full length of the living room, never deducted on the original plan.
Main room Secondary room Load-bearing wall (20 cm) Carrez boundary Carrez boundary Apparent boundary (partitions) Surface lost in the wall
The calculation that reveals the real discrepancy
Take a concrete case in Antibes. VEFA plan: stated Carrez surface S_plan = 71.0 m². You measure with a laser: apparent length L_app = 10.50 m, apparent width l_app = 6.80 m. Apparent surface S_app = L_app × l_app = 10.50 × 6.80 = 71.40 m². Paradox? No.
The real Carrez surface formula is: S_Carrez = (L_app + Σe_walls/2) × (l_app + Σe_walls/2) – ΣS_ducts. Here, the load-bearing walls have a thickness e = 0.20 m on each side. The service ducts account for S_ducts = 0.85 m². So: S_Carrez = (10.50 + 0.20) × (6.80 + 0.20) – 0.85 = 10.70 × 7.00 – 0.85 = 74.90 – 0.85 = 74.05 m² (error – see below).
Common mistake: I added the thickness of both walls. In reality, Carrez surface is measured from inside the perimeter load-bearing walls. If the 20 cm wall is shared with another unit, only half of it counts. Let’s redo this with a perimeter load-bearing wall 0.20 m thick on two sides only: S_Carrez = (10.50 + 0.10) × (6.80 + 0.10) – 0.85 = 10.60 × 6.90 – 0.85 = 73.14 – 0.85 = 72.29 m².
Comparison: discrepancy Δ = |S_plan – S_Carrez| = |71.0 – 72.29| = 1.29 m². The Carrez Law (Art. 46-1) allows a tolerance of 5% of the stated surface, i.e. 71.0 × 0.05 = 3.55 m². Here, 1.29 m² < 3.55 m²: technically within tolerance. But a professional Carrez measurement requires millimetre-level precision on linear dimensions. If the dimensional error exceeds 1%, the surface can fall outside tolerance. What this means in practice: a 5 cm error over a 5 m length is enough to invalidate the plan.
If you do nothing, here’s what happens
In 6 months, you’ll have settled into the space. But your property’s value has already been cut. In Antibes, the price per m² averages around €7,500. That missing 2.5 m² is nearly €19,000 wiped off the resale value. No one will reimburse you for it.
Over 5 years, the problems compound. A miscalculated surface often masks design flaws. In Antibes it’s not uncommon to find homes where the surface shortfall was hiding a ceiling-height issue that didn’t comply with the co-ownership regulations. Secondary defects then appear: abnormal condensation because the air volume is reduced, degraded acoustics because the partitions are thinner than planned. The cost of correction then exceeds €15,000.
Remedies and guarantees: what you’re entitled to demand
The Carrez Law (Art. 46-2) applies: where the discrepancy exceeds 5%, you’re entitled to a proportional price reduction. For a 2.5 m² shortfall on 71 m² (i.e. 3.5%), the 5% threshold is not reached: a price reduction is not automatic, unless a contradictory Carrez survey reveals a larger shortfall. The Carrez rules (Decree No. 97-532) require the stated surface to match the as-built reality. Procedure: send the developer a formal notice by registered letter with acknowledgement of receipt, giving 30 days to respond. If they refuse, request a contradictory expert survey. As a last resort, the Grasse judicial court. Bottom line: don’t let this slide – developers are counting on you giving up.
Frequently Asked Questions
How do you correctly measure Carrez surface in a new-build apartment in Antibes?
Carrez surface is measured inside the load-bearing walls, excluding partitions, service ducts and non-habitable areas. Use a laser measuring tool and follow the method set out in Article 46-1 of the Carrez Law: measure the clear floor area and deduct any surfaces that don’t count. In Antibes, a 2.5 m² discrepancy from the VEFA plan justifies a contradictory survey by an expert.
What’s the legal tolerance for the gap between actual Carrez surface and the surface stated in a VEFA contract?
The Carrez Law allows a tolerance of 5% of the stated surface. For a 71 m² apartment, that margin is 3.55 m². Beyond that, the seller must reduce the price proportionally. In Antibes, where the m² sells for around €7,500, even a 1.29 m² discrepancy represents a loss of nearly €10,000.
What should I do if my new-build apartment’s Carrez surface in Antibes is smaller than the VEFA plan?
Have a contradictory survey carried out by a land or building surveying expert. If the discrepancy exceeds 5%, you can request a price reduction from the seller within one year of the deed of sale being signed. Keep all documents (VEFA plan, deed of sale). In Antibes, 40% of VEFA disputes exceed the legal tolerance.
How much does a contradictory Carrez surface calculation cost in Antibes?
A topographic survey by an expert costs between €300 and €800 depending on the surface area and complexity. In Antibes, this cost quickly pays for itself if the surface discrepancy exceeds 2 m², since the loss in value can reach €15,000. The turnaround is typically 1 to 2 weeks.
Why does my new-build apartment in Antibes have a smaller Carrez surface than the VEFA plans?
VEFA plans can contain dimension errors, undeducted service ducts, or mismeasured load-bearing walls. For example, a 25 cm-thick duct running the full length of the living room can account for a 0.85 m² loss. Total-station surveys often reveal these discrepancies, especially in recent developments in the Fontonne district.
Need an expert? Check out our dedicated page: Boundary disputes and land survey expertise – free quote within 24h across the Alpes-Maritimes and Var.
📅 Updated on 04/08/2026 – By Cassini Expertise, independent building expert covering the 06 & 83 departments. Free quote: 04 22 46 06 04.
Related reading:
Further reading: Undersized VEFA Parking Space in Nice: What Are Your Rights? · Carrez Area in VEFA Purchases: Measuring and Tolerance · Carrez Area in VEFA Off-Plan Sales: Calculation and Errors
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Survey carried out by Frédéric Faucouneau, independent building expert – Antibes, Alpes-Maritimes (06), Var (83), Bouches-du-Rhône (13). Find out more
📅 Last updated 06/11/2026 - Cassini Expertise, independent building expert – departments 06, 83 and 13.