Apartment buildings: the complete regulatory picture 2026

A collective residential building is defined in the construction code as any building containing more than two dwellings one above another. The technical regulation applicable varies with the family, determined by the height of the lowest floor of the highest habitable level: families 1 to 4 up to 50 m, then the high-rise regime beyond, with its own regulation.

The order of 31 January 1986 as amended fixes the fire resistance of structures, floors, walls and doors. Floors between habitable levels are REI 60. Partitions separating two dwellings are EI 60. Service risers passing through the dwellings are classified EI 60 to EI 90 according to the family. Flat entrance doors are at least EI 30, rising to EI 60 in family 4.

From family 3, stairs must be enclosed, with the shaft separated by EI 60 construction and EI 30 doors. Stairs may be ventilated naturally, through a roof light of at least 1 m², or pressurised. In family 4, pressurisation of the stair shaft above 20 Pa is mandatory to guarantee escape despite smoke.

ℹ Pressurising the stair shaft The rule: a differential pressure of at least 20 Pa between shaft and landing with the door open. Supply rate: sized to compensate leakage plus one open door. Automation: linked to a detector or the fire safety control equipment. Commissioning: an in-situ pressure measurement by the technical control office.

Basement parking in a residential building falls under the same order, in its articles on covered car parks. The structuring requirements are compartments of at most 3,000 m², smoke extraction at 900 m³/h per vehicle or per circulation aisle, and REI 90 separation of the car park from the dwellings.

The acoustic order of 30 June 1999 fixes the minimum insulation between dwellings and between dwellings and common parts. It applies to every new apartment building and to substantial refurbishment.

Acoustic performance requires constructional choices from the design stage: floating screeds at 10 to 20 €/m² extra, acoustic linings to lightweight partitions, movement joints between blocks. Lifts must be isolated from the dwellings by anti-vibration mountings.

Every common part of a new apartment building must be accessible. External routes, entrance halls, corridors, communal rooms — cycle stores, bin stores, cellars — and lifts must respect minimum widths, tactile floor guidance above 50 dwellings, and controls at an accessible height.

ℹ Accessibility in the common parts: the key points External route: gradient at or below 5 %, up to 8 % over 2 m, width at least 1.40 m. Halls and corridors: at least 1.20 m, with 0.90 to 1.20 m possible below 10 dwellings. Lift: door at least 0.80 m, car at least 1.00 × 1.30 m, controls between 0.90 and 1.30 m. Cycle stores: accessible above 15 dwellings. Entryphone: at 0.90 to 1.30 m, with visual contrast and audible feedback.

The environmental regulations have applied to apartment buildings since 1 January 2022. The key indicators are the bioclimatic need, tied to compactness and insulation; non-renewable energy consumption; and the carbon impact of the materials across the life cycle. Communal gas heating has been prohibited since 1 January 2022.

ℹ The principal constraints Communal heating: a water-source heat pump, a district network supplied from renewables, or cogeneration. Gas is prohibited. Construction carbon: standard reinforced concrete is penalised, so consider low-carbon cement, a mixed concrete and timber structure, or timber frame. Summer overheating, below 1,250 degree-hours: solar protection mandatory on south and west façades. Thermal bridging: external insulation is preferable to internal, to limit bridging at continuous slabs.

ℹ ✔ Summary for the economist Construction cost of a standard new apartment building: 1,630 – 2,450 €/m² of floor area, excluding land and external works. From family 3, technical control covering soundness and safety is mandatory, at 0.5 to 1 % of the works. On acoustics, allow a budget for in-situ testing to clear the handover defects, at 510 to 2,040 € per dwelling. On the environmental regulations, anticipate the low-carbon structural choice at brief stage: the effect on the structural cost is + 5 to + 15 %.

The new apartment article treats the regulation from the angle of the individual flat. Accessibility standards are covered in detail in the accessibility article. Fire safety is developed in the fire article. The environmental regulations have their own article. For buildings above 50 m, see the high-rise article.

ℹ The construction economist on demand. Your apartment scheme needs an estimate that takes in fire, acoustics, accessibility and the environmental regulations. Submit your programme on quostra.com and an economist prices the regulatory constraints from the brief.

Reference basis of the figures

The ratios per square metre and per item on this page are stated in January 2026 values. They were updated from January 2025 values, the basis adopted for the whole cocoon, using the BT01 all-trades index published monthly by INSEE on its 2010 base: 132.0 in January 2025, 134.7 in January 2026, a coefficient of 1.0205.

The global amounts quoted as examples, and any rents, charges or receipts expressed per year or per night, remain on their own basis: a building cost index does not apply to them.

To bring the ratios forward, apply the usual revision formula: updated value = page value × (BT01 for the month in question / 134.7). The BT01 measures contractors' input costs, labour at 44.9 % and materials at 36.5 %, not the prices actually tendered.