🧮 Surface Measurement
🏢 The Carrez Law Diagnosis: Essential for selling in co-ownership
🔹 Definition
Stemming from Law No. 96-1107 of December 18, 1996, the Carrez Law requires the seller of a co-owned property to indicate the exact private surface area of the dwelling in the deed of sale.
It aims to protect the buyer by guaranteeing transparency on the real square footage of the property.
🔹 What is measured?
The Carrez surface corresponds to the private floor area, after deducting walls and partitions, steps and staircases, technical conduits, door and window openings.
Surfaces with a ceiling height of less than 1.80 meters are excluded from the calculation.
👉 Therefore not counted: balconies, terraces, cellars, parking spaces, garages, unfinished attics or common areas.
🔹 When is it mandatory?
Carrez measurement is mandatory when selling: an apartment or a house located in a horizontal co-ownership (residential subdivision), as long as the private surface exceeds 8 m².
Individual houses not subject to a co-ownership agreement are therefore not concerned.
🔹 In case of error?
If the actual surface is less than more than 5% compared to what is stated, the buyer can request a proportional price reduction.
Below 5% difference, no action is possible.
If the Carrez mention is absent, the sale can be canceled.
🔹 Validity
Carrez measurement has no limited duration, as long as the configuration of the property does not change.
However, in case of work modifying the surface (renovation, partition, extension), a new measurement is necessary.
Its legal value is generally recognized for 12 months for a claim.
🏠 The Boutin Law Diagnosis: Mandatory for rental
🔹 Definition
Introduced by Law No. 2009-323 of March 25, 2009 (known as the "Boutin Law"), this regulation requires the landlord to indicate the habitable surface of the dwelling in any unfurnished lease for use as a primary residence.
The objective is to guarantee the tenant reliable information on the size of the dwelling they occupy.
🔹 How is it calculated?
The habitable surface (article R.111-2 of the Building and Housing Code) corresponds to the constructed floor area, after deduction of walls, partitions, steps, stairwells, conduits and door and window openings.
Not included: rooms with a height of less than 1.80 m, unfinished attics, cellars, garages, storage areas, as well as balconies, terraces, loggias or unheated verandas.
🔹 When is it mandatory?
Boutin Law measurement is mandatory for all unfurnished rentals for use as a primary residence, whether it is an apartment, an individual house or a co-owned dwelling.
On the other hand, it does not apply to furnished rentals, seasonal rentals or secondary residences, unless the landlord chooses to indicate it voluntarily.
🔹 In case of error?
If the actual surface is less than more than 5% compared to what is stated in the lease, the tenant can request a proportional reduction in rent.
If the surface is larger, the landlord cannot claim a supplement.
The absence of surface mention is a formal irregularity, but does not cancel the lease.
🔹 Validity
The Boutin diagnosis has no fixed duration, except in case of work modifying the surface of the dwelling.
It is therefore necessary to have it established by a certified professional in order to avoid any future dispute.
📎 In summary
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Carrez Law: mandatory for the sale of a co-owned property (private surface area).
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Boutin Law: mandatory for unfurnished rental for use as a primary residence (habitable surface area).
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Two different methods, two distinct obligations, but one common objective: to guarantee transparency and protect both buyers and tenants.
