French Building Regulations: One National Code on Chippy Tools

French Wet-Room Waterproofing: NF DTU 52.2 and the SPEC System

Wed, 05 Aug 2026 00:00:00 +0000

The requirement

In France, NF DTU 52.2 is the rule book for wet-room tiling. It rates each room by how wet it gets. The wettest rooms, like shower and bath zones, need a membrane under the tile. That system is SPEC, set out in CSTB’s CPT n° 3714. Both are paid standards.

France does this its own way. Australia’s NCC prints its rule in a public code clause. France does not. The rule sits in a DTU instead. DTU is short for Document Technique Unifié. That is a trade standard you must buy, not free public guidance.

France's Minimum Ceiling Height: the 2.20 m Décence Rule

Wed, 05 Aug 2026 00:00:00 +0000

The requirement

In practice, the minimum is 2.20 m for a main room (pièce principale). That comes from Article 4 of Décret n°2002-120 du 30 janvier 2002, the décence (decent-housing) rule. If the height is under 2.20 m, the room can pass instead with a habitable volume of 20 m³. France has no separate building-permit clause for ceiling height.

This “logement décent” (décence) rule is housing law, not a permit-stage design clause. It says when a dwelling is decent enough to rent out. Strictly, it is a tenancy and habitability floor. It is not a technical new-build clause, the way a Building Regs Approved Document might set one. But it is the number every French professional reaches for. No separate construction-stage figure exists. So use the 2.20 m figure. It is real, current, and citable. Just know what kind of rule it is.

French Foundations: No Fixed Depth — Soil Study & Frost Zones

Wed, 05 Aug 2026 00:00:00 +0000

The requirement

France sets no fixed foundation depth. There is no single number in the Code de la construction et de l’habitation, and none in any free official text. Depth comes from a ground study and your site’s frost zone. The rules are NF DTU 13.1 and NF P 94-261. Anyone quoting one centimetre figure as “the French rule” is guessing.

Here is how it works. NF DTU 13.1 (September 2019) covers shallow strip footings. It is read with NF P 94-261 (June 2013, amended February 2017). That second standard is the French rule book for Eurocode 7. It splits France into hors-gel (frost-free) climate zones. The further from the coast and the higher up your site sits, the deeper your footing must go.

French Ramp Gradients: No General Rule for a Self-Build

Wed, 05 Aug 2026 00:00:00 +0000

The requirement

France has no general ramp slope rule for a self-built house. No 1:12, no percentage, nothing in the Code de la construction et de l’habitation. The 5%, 8% and 10% figures you see quoted are accessibility rules. By law, those rules exempt a house built by or for its own owner (CCH art. L111-7-1).

So who do those rules bind? A house built for sale or rent. Also collective buildings and ERP, which are public-facing buildings. Building your own home? Then that whole regime is not your rule. The numbers in it are a guide for you, not the law.

French Stair Rules: No Fixed Dimensions, a Real Guard-Rail Law (CCH)

Wed, 05 Aug 2026 00:00:00 +0000

The requirement

France sets no fixed rise, going or pitch for a private house stair. The Code de la construction et de l’habitation (CCH) has no maximum rise or minimum going for a self-built home. Builders use the loi de Blondel instead: 2h + g ≈ 60–64 cm. That is a trade rule, not law.

Websites that quote you a fixed “French code number” are guessing. Or they are quoting the access rules, which is a different scope. More on that below.