Civil Code regime
CC arts. 1469-1471. The sale of real estate by surface implies the price is set on the surface. If actual is smaller:
- Difference below 5%: the buyer cannot refuse full price (the 'corridor' rule).
- Difference 5%-10%: proportional price reduction.
- Difference over 10%: option between proportional reduction or termination.
Which surface to compare
Compare the surface stated in the contract (private or deed) vs. actual measured under a uniform criterion. Typical categories:
- Useful surface: habitable, excluding walls and common elements.
- Built surface: includes walls and pro-rata of common areas.
- Terrace, balcony, storage or garage surface: measured independently.
Caution: if the contract says 'useful' but the developer measured 'built', the technical survey reconciles the figures.
Procedure
- Independent technical measurement.
- Difference and reduction calculation.
- Pre-litigation letter to the developer with amounts.
- If unattended: civil claim (CC art. 1471) for reduction and/or termination.
Typical cases
- Property advertised as 110 m² useful, actual 98 m² (-11%): termination option.
- Terrace 25 m² delivered as 18 m² (-28%): proportional reduction.
- Linked storage 8 m² delivered as 5 m² (-37%): reduction + functionality loss compensation.
Frequently asked questions
What if the deed says 'as measured' without specific square metres?
It's an unfair clause if used to dodge the difference. Technical survey + claim for material breach.
When to measure?
Best to measure before completing. If already completed, measure as soon as you suspect and keep photos with tape.
Does the difference include walls?
Depends on contractual criterion. The survey must use the same criterion as the contract. If unspecified, majority case law favours useful habitable surface.