German Building Rules: National DIN Numbers, State-by-State Law on Chippy Tools

German Wet-Room Waterproofing: DIN 18534, the Quasi-Mandatory Standard

Mon, 03 Aug 2026 00:00:00 +0000

The requirement

Here’s the honest answer: no Landesbauordnung sets a wet-room waterproofing figure. Room height, natural light and ventilation each get a mention in the 16 Länder’s own building laws (see the room-height page below), but shower and wet-room membrane detail isn’t one of the things a Landesbauordnung itemises at all. For that, Germany points — quite firmly — to a single technical standard: DIN 18534, “Abdichtung von Innenräumen” (waterproofing of interior spaces).

Does Germany Have a Fixed Foundation Depth?

Mon, 03 Aug 2026 00:00:00 +0000

The requirement

Germany doesn’t set one national foundation depth. DIN 1054 — the geotechnical design standard — gives 0.80 m below finished ground level as its general baseline assumption. But that’s a starting point, not a minimum you can rely on everywhere: the depth that actually applies to your job is set by the ground itself, worked out under DIN EN 1997-1 (Eurocode 7) together with DIN 1054, via a geotechnical assessment of the site.

Does Germany Have a National Minimum Room Height?

Mon, 03 Aug 2026 00:00:00 +0000

The requirement

Here’s the honest answer: Germany sets no single national minimum room height. There’s no federal building code to set one — building law is made by each of the 16 Länder, and the figure genuinely differs from Land to Land.

Where the “2.40 m” figure comes from. The Musterbauordnung (MBO) — a model law published by the Bauministerkonferenz to keep the 16 Länder’s laws roughly aligned — uses 2.40 m as its illustrative minimum lichte Raumhöhe (clear room height) for a habitable room (Aufenthaltsraum). But the MBO has no legal force of its own. It only matters as a template, and several Länder diverge from it materially:

German Ramp Gradients: DIN 18040-2 Accessible Ramp Rules

Mon, 03 Aug 2026 00:00:00 +0000

The requirement

Germany’s fixed ramp numbers all come from one standard — DIN 18040-2, “Barrierefreies Bauen — Wohnungen” (accessible/barrier-free building — dwellings), current edition 2011-09 — and they apply specifically to an accessible ramp. Before you read off a gradient, know whether that’s actually what you’re building.

The accessible ramp run. DIN 18040-2 sets the longitudinal gradient at no steeper than 6% (1:16.7), with no cross-fall permitted on the ramp run itself. It also sets:

German Stair Rules: DIN 18065 Rise, Going & Guard Heights

Mon, 03 Aug 2026 00:00:00 +0000

The requirement

A German residential stair is set out to DIN 18065, the technical standard for Gebäudetreppen (building stairs), current edition 2020-08. Like every DIN standard, it only binds where a Land’s building law brings it in — but in practice, the geometry numbers below are the ones builders across the country work to.

Rise (Steigung) — how tall each step is.
Going (Auftritt) — how deep each step is, the flat part you stand on.

For a Wohngebäude (residential) stair, DIN 18065 gives a working band of 140–200 mm rise and 230–370 mm going. Ship the binding edges: don’t build a rise over 200 mm, and don’t build a going under 230 mm. Keep every step in a flight the same so the stair climbs evenly.