PLU Cannes UB: Non-Compliant Ground Coverage – How to Appeal

URBAN PLANNING — FRENCH RIVIERA

You bought a plot in Cannes, zone UB. The building permit mentions a ground coverage of 180 m². You build a pool, a covered terrace, a garden shed. Everything seems normal. Then one day, a neighbor points out that your slab extends beyond the limit. You measure: 192 m². 12 m² too much. The PLU Cannes zone UB allows 40% coverage on your 450 m² plot, i.e., max 180 m². You are already in violation. And the developer says it’s a survey error? Not so simple.

Why Your Ground Coverage Is Often Underestimated

The permit’s site plan shows dimensions. But ground coverage is not limited to exterior walls. The PLU Cannes defines ground coverage as the vertical projection of all constructions, including roof overhangs, unenclosed terraces, pools (except buried basins), and exterior stairs. Many forget these elements. On a file in Cannes last year, I measured an 80 cm roof overhang that added 14 m² of unaccounted coverage. The owner had followed the builder’s plan, but the actual calculation was different.

The Calculation That Tips the Scale: Ground Coverage According to PLU Cannes

The formula is simple: Ground coverage = Σ (vertical projection area of each construction). But the devil is in the details. For your 450 m² plot in zone UB, the PLU Cannes allows 40% i.e., 180 m². Let’s recalculate: 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? No, the overhang only counts for the roof projection beyond the walls. If the roof overhangs 0.80 m on all four sides, the overhang coverage 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 buried basin): if the surrounding deck is 12 m², total coverage becomes 160+48+44.16+12 = 264.16 m², i.e., 58.7% of the plot. Well above the allowed 40%. This type of exceedance is common on the French Riviera, where owners add terraces and pools without recalculating coverage.

Consequences of Non-Compliant Ground Coverage in Cannes

Exceeding ground coverage can lead to a building permit refusal, an obligation to demolish, or a fine of up to €6,000 per excess square meter (Article L.480-4 of the French Urban Planning Code). Moreover, the sale of the property can be blocked: the notary is required to verify compliance. In a case in Nice, an owner had to demolish a 30 m² terrace to regularize, costing €15,000 in work. In Antibes, another owner negotiated a PLU modification after proving a calculation error. But these appeals are lengthy and costly. Better to anticipate.

What to Do If Your Ground Coverage Exceeds? Solutions and Appeals

If you are already in violation, several options are available:

• Regularization: file a modified building permit if the exceedance is less than 5% and height, setback, etc. rules are respected. In Cannes, the city hall examines each case.
• Partial demolition: remove non-compliant elements (terrace, shed) to fall back under the threshold.
• Graceful appeal: contest the decision if the error comes from the administration (e.g., miscalculation of floor area).
• Expertise: hire a surveyor or architect for an accurate measurement. In a case in Cannes, I found that the builder had forgotten to account for exterior stairs, which reduced the coverage by 8 m².

To avoid these problems, before any purchase or construction, have a professional calculate the ground coverage. The PLU Cannes zone UB is strict, but good preparation will save you surprises. Need advice? Contact an urban planning expert specialized in the PACA region.

📅 Mis à jour le 26/07/2026 — Par Cassini Expertise, expert bâtiment indépendant 06 & 83. Devis gratuit : 04 22 46 06 04.

Questions fréquentes

How to appeal PLU Cannes UB ground coverage refusal?

To appeal, you must file a recours gracieux with the mairie within two months of the refusal, explaining why your project complies or why the rule is misapplied. If rejected, you can then file a recours contentieux with the administrative court within two months of that rejection.

What is the maximum ground coverage in zone UB Cannes?

In zone UB of Cannes, the maximum ground coverage (emprise au sol) is typically 50% of the plot area, but this can vary based on specific sub-zones or plot size. Check the exact PLU regulations for your parcel, as corner plots or those over 1000 m² may have different limits.

Can I exceed the UB ground coverage limit with a permit?

Exceeding the limit is only possible if you obtain a formal derogation (dérogation) under specific conditions, such as for accessibility or architectural heritage, but this is rare. Otherwise, you must adjust your project to comply or appeal the refusal if you believe the limit was miscalculated.

📅 Mis à jour le 19/09/2026 — Cassini Expertise, expert bâtiment indépendant (06·83·13·40).