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

The requirement

For a home (Wohngebäude) stair, DIN 18065 caps the rise at 200 mm and sets the going at 230 mm or more. The step formula, 2 × rise + going, must land between 590 mm and 650 mm. Guard heights are not in DIN 18065. Each Land sets those in its own building law.

The rise (Steigung) is how tall each step is. The going (Auftritt) is how deep each step is, the flat part you stand on. DIN 18065 is the German standard for building stairs (Gebäudetreppen), current edition 2020-08. Like every DIN standard, it only binds where a Land’s building law brings it in. In practice, builders across the country work to these numbers.

For a home stair, the standard allows a 140–200 mm rise and a 230–370 mm going. Stay at the binding edges. Do not build a rise over 200 mm. Do not 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. Take twice the rise, then add the going. DIN 18065 wants that sum between 590 mm and 650 mm. It is a quick check that a stair is not too steep or too shallow. You may see a simple “63 cm” target quoted. That is a rule-of-thumb midpoint, not the standard’s band. Work to 590–650 mm.

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, reduced headroom is allowed at the edges of a stair. A central zone must still keep 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, and 1000 mm for larger buildings. Read that as the standard’s own guidance figure, not a fixed legal minimum. For a normal house, most Länder only ask that a stair be “wide enough for the expected traffic”. The statute itself has no fixed number.

Guarding: the number that changes by Land

One guard figure is the same everywhere. Leave no clear gap wider than 120 mm (12 cm) between infill members. That applies wherever small children may be around without an adult watching.

Guard height is different. DIN 18065 does not set it at all. It is a matter of building law, so each Land sets its own. 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. The confirmed cases show real spread. North Rhine-Westphalia writes these exact centimetre figures into its own statute (§39 BauO NRW). There you can cite a clause number directly. Bavaria’s Art. 36 BayBO gives no number at all. It only asks that a guard be “ausreichend hoch und fest” (sufficiently high and sturdy). The other 14 Länder were not checked against their statute text for this figure. Treat the table as a fair working guide, and check your Land’s page for the confirmed answer.

Work it out on site

Say your floor-to-floor height is 2800 mm. You are setting out a home stair.

1. Pick how many risers. 2800 ÷ 200 (the tallest a rise can be) = 14. Round up if it does not divide evenly. Here 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. That sits inside the 590–650 mm band, so the pitch is comfortable.

The calculator does this rounding and the step-formula check for you. It also 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: one 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.