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

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.

A stair also has to pass the Schrittmaßregel — the step formula, twice the rise plus the going. DIN 18065 sets that between 590 mm and 650 mm. It’s a quick way to confirm a stair isn’t too steep or too shallow before you cut a stringer. (You’ll sometimes see a simplified “63 cm” target quoted — that’s a rule-of-thumb midpoint, not the standard’s actual band, so work to 590–650 mm instead.)

Two more numbers round it out:

• Headroom — at least 2000 mm clear, measured from the front edge (Vorderkante) of any tread. In a building with up to 2 dwellings, a reduced headroom is permitted at the edges of a stair, provided a central zone keeps the full 2000 mm clear — confirm the exact figures against DIN 18065 directly.
• Width — DIN 18065 recommends 800 mm usable width for a stair serving up to two dwellings (1000 mm for larger buildings). Read that as the standard’s own guidance figure, not a fixed legal minimum — for an ordinary house, most Länder only require a stair be “wide enough for the expected traffic,” with no fixed number in the statute itself.

Guarding — the number that changes by Land

The guard opening rule is the one figure that’s the same everywhere: a clear gap of no more than 120 mm (12 cm) between infill members, wherever unsupervised small children may be present.

Guard height is different. It isn’t set by DIN 18065 at all — it’s a matter of building law, so it’s set Land by Land. Most Länder pattern their guard clause on the same Musterbauordnung (MBO) §38 baseline:

Treat this table as the model, not the law — the MBO itself has no legal force. Confirmed cases show real variation: North Rhine-Westphalia spells out these exact centimetre figures in its own statute (§39 BauO NRW), so you can cite a clause number directly. Bavaria’s Art. 36 BayBO doesn’t state a number at all — it only requires a guard be “ausreichend hoch und fest” (sufficiently high and sturdy), leaving the figure to accepted technical rules. The other 14 Länder weren’t independently checked against their statute text for this specific figure — treat the table above as a reasonable working assumption, and check your Land’s page for the confirmed answer.

Work it out on site

Say your floor-to-floor height is 2800 mm and you’re setting out a residential stair.

1. Pick how many risers. 2800 ÷ 200 (the tallest a rise can be) = 14. Round up if it doesn’t divide evenly — 2800 ÷ 14 = 200 mm per rise exactly, right at the limit.
2. Set the going. Try 230 mm, the minimum. Fourteen risers means 13 goings, so the stair runs 13 × 230 = 2990 mm along the floor. Check it fits the space.
3. Check the step formula. 2 × 200 + 230 = 630 mm — inside the 590–650 mm band, so the pitch is comfortable.

The calculator does this rounding and the step-formula check for you, and keeps every rise even.

Do it in 5 seconds

Related

• German building rules hub — how the national DIN layer and the 16 Länder’s own building law fit together.
• Irish stair & barrier rules — a single national figure set, for comparison.

Sources

• DIN 18065:2020-08 — Gebäudetreppen, the Wohngebäude geometry table (rise/going/step-formula), headroom and the DIN’s own recommended width and guard-gap figures. DIN standards are commercial (Beuth/DIN e.V.) — verify at din.de / beuth.de.
• Musterbauordnung (MBO) §38 — Umwehrungen, the guard-height model most Länder pattern their own law on. Read the model text at bauministerkonferenz.de.

Read this first. DIN 18065 is a paid standard — DIN e.V. doesn’t publish free full text, so the figures above are drawn from consistent, repeated professional and technical guidance quoting the standard, not from din.de itself. Guard heights are set by each Land’s Landesbauordnung, not nationally — the table above is the common MBO-model baseline, confirmed directly in statute for North Rhine-Westphalia and confirmed absent from Bavaria’s statute text; the other 14 Länder haven’t been individually checked. Always confirm the current DIN edition and your Land’s current LBO text before you build to a figure here.