Regulatory Ceiling Height Calculator (Decent Housing)
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/9/2026
France's decent housing decree requires at least one main room to have a floor area of at least 9 m² and a ceiling height of at least 2.20 m, or failing that a habitable volume of at least 20 m³. A 12 m² room with a 2.5 m ceiling height (30 m³) meets both criteria.
Explanation
Decree n°2002-120 of January 30, 2002 on the characteristics of decent housing, codified in article R.111-2 of France's Construction and Housing Code, requires housing to include at least one main room meeting one of the following two criteria, which are alternatives, not cumulative: either a floor area of at least 9 m² combined with a ceiling height of at least 2.20 m, or, failing that, a habitable volume of at least 20 m³ for the whole room. This second path allows, for example, an attic room or one with reduced height but sufficiently large floor area to still be considered decent, as long as its total volume reaches the threshold. This decency criterion governs whether housing can be legally rented in France: housing that doesn't meet it exposes the landlord to tenant recourse (bringing it up to code, rent reduction) — a consequence worth knowing before any purchase intended for rental or any attic conversion project. This calculator applies the rule as codified but doesn't cover the other cumulative decent-housing criteria (natural lighting, utilities, safety), which must be checked separately — much like our required insulation thickness calculator covers another of these independent performance criteria. When in doubt about an existing property — especially when the Carrez law floor area already excludes certain low-height parts from the count — an assessment by a professional remains the only reliable way to confirm a home's full decency.
Example: a 12 m² room with a 2.0 m ceiling height
Inputs
Floor area: 12 m². Ceiling height: 2.0 m.
Calculation
The 2.0 m height is below the 2.20 m threshold, but the habitable volume (12 × 2.0 = 24 m³) exceeds the 20 m³ threshold.
Result
The room is compliant thanks to the alternative habitable-volume criterion.
Frequently asked questions
Must both criteria (area+height and volume) be met at the same time?
No, these are two alternative paths: only one of the two conditions needs to be met for the room to satisfy the decent housing height criterion. A room can therefore be compliant solely through its habitable volume even if its ceiling height is below 2.20 m.
Is this criterion enough to make housing decent under the law?
No, a home's decency depends on several distinct cumulative criteria (floor area and height or volume, but also natural lighting, absence of safety hazards, presence of basic utilities and fixtures). This calculator covers only the floor area, height, and volume criterion, one element to check among others.
Does this criterion apply room by room or to the whole home?
The decree requires that at least one main room in the home meet this criterion, not necessarily every room. Housing with, for example, a large compliant living room and a lower attic bedroom can therefore still be considered decent on this specific point.