Cannes UB Zoning: Non-Compliant Ground Coverage – Legal Recourse

URBAN PLANNING — FRENCH RIVIERA

You bought a plot of land in Cannes, zone UB. The building permit states a ground coverage (emprise au sol) of 180 m². You build a pool, a covered terrace, a garden shed. Everything looks fine. Then one day, your neighbour points out that your slab goes beyond the line. You measure with a ruler: 192 m². 12 m² too much. The Cannes UB zoning plan (PLU) allows 40% ground coverage on your 450 m² plot, i.e. 180 m² maximum. This limit is calculated by vertically projecting the entire footprint of the constructions onto the ground, including any overhangs. You’re already in breach. And the developer tells you it’s a surveying error? It’s not that simple.

Why your ground coverage is often underestimated

The site plan attached to the permit shows measurements. But ground coverage isn’t limited to the exterior walls. The Cannes zoning plan defines ground coverage as the vertical projection onto the ground of all constructions, including roof overhangs, uncovered terraces, swimming pools (excluding buried basins), and outdoor staircases. This definition stems from Article R.431-5 of the French Planning Code (Code de l’urbanisme). Many owners overlook these elements. It’s not unusual to measure an 80 cm roof overhang that added 14 m² of uncounted ground coverage. The owner had followed the builder’s plan, but the actual calculation was different.

The calculation that tips the balance: ground coverage under the Cannes zoning plan

The formula is simple: Ground coverage = Σ (ground projection area of each construction). But the devil is in the details. For your 450 m² plot in zone UB, the Cannes plan allows 40%, i.e. 180 m². Let’s redo the math: house 160 m², covered terrace 48 m² (8×6), roof overhang (0.80 m on each side): (10+2×0.8)×(16+2×0.8) – 10×16 = 11.6×17.6 – 160 = 204.16 – 160 = 44.16 m². The overhang only counts for the roof’s projected area beyond the walls. If the roof overhangs by 0.80 m on all four sides, the overhang’s footprint is: (10+0.8+0.8)×(16+0.8+0.8) – 10×16 = 11.6×17.6 – 160 = 204.16 – 160 = 44.16 m². Add the pool (excluding the buried basin): if the surrounding deck is 12 m², total ground coverage becomes 160+48+44.16+12 = 264.16 m², or 58.7% of the plot. Far beyond the 40% allowed. This kind of overrun is common on the French Riviera, where owners add terraces and pools without recalculating ground coverage.

The consequences of non-compliant ground coverage in Cannes

Exceeding the ground coverage limit can lead to a building permit refusal, a demolition order, or a fine. Penalties are set out in Articles L.480-4 and R.480-1 of the French Planning Code, with amounts scaled to the severity of the breach and the illegally built surface area. What’s more, the sale of the property can be blocked: the notary is required to verify compliance. These obstacles can be overcome with an objective expert assessment and a strategy tailored to your situation.

What to do if your ground coverage exceeds the limit: solutions and remedies

If you’re already in breach, several options are available to you:

• Regularisation: file an amended building permit if the overrun is under 5% and the height, setback, and other rules are respected. In Cannes, the town hall reviews each case individually.
• Partial demolition: remove the non-compliant elements (terrace, shed) to bring the property back under the threshold.
• Administrative appeal: challenge the decision if the error originated with the administration (e.g. an incorrect floor area calculation).
• Expert assessment: bring in a planning expert or architect for a precise, documented survey of the constructions. A rigorous recalculation can reveal misinterpretations of the zoning plan or the original blueprint.

To avoid these issues, have a ground coverage calculation carried out by a professional before any purchase or construction. The Cannes UB zoning plan is strict, but proper preparation will spare you unpleasant surprises. Need an opinion? Contact an independent planning expert covering the PACA region.

📅 Updated 25/07/2026 — By Cassini Expertise, independent building expert covering 06 & 83. Free quote: 04 22 46 06 04.

Frequently Asked Questions

What is the maximum ground coverage in zone UB in Cannes?

In zone UB of the Cannes zoning plan, the maximum ground coverage varies by sector. For your plot, the allowed percentage is stated in the written regulations and the zoning map. Check directly with the Cannes town hall’s approved zoning plan or with the planning department to confirm the applicable percentage.

What should I do if my ground coverage exceeds the UB limit?

If your existing or planned construction exceeds the allowed ground coverage, you can file an administrative or judicial appeal against the building permit, or request a minor adjustment if conditions justify it. It’s advisable to consult a planning lawyer.

Can non-compliant ground coverage in zone UB be regularised?

Regularisation is possible if the construction predates the zoning plan and you apply for a regularisation permit, but it will only be granted if the non-compliance is minor and doesn’t undermine planning rules. Otherwise, partial demolition may be required.

📅 Mis à jour le 25/09/2026 — Cassini Expertise, expert bâtiment indépendant (06·83·13·40).