DIN 18065: The Complete Guide to German Staircase Standards
DIN 18065 is the German national standard governing the design, construction, and dimensions of stairs in buildings. First published in 1934 and most recently updated in 2015, it provides binding requirements for all new construction and major renovations in Germany. Understanding this standard is essential for anyone planning to build or modify a staircase.
Scope and Application
DIN 18065 applies to all permanently installed stairs in buildings that serve as access routes for people. This includes stairs in residential buildings, commercial and public buildings, industrial facilities, and outdoor access stairs to buildings. The standard does not apply to temporary stairs, ladders, escalators, or movable stairs.
The standard defines three categories of stairs, each with different dimensional requirements: stairs in residential buildings (the most common category), stairs in public and commercial buildings (stricter requirements), and secondary stairs and attic stairs (relaxed requirements).
Rise and Run Requirements
Residential Building Stairs
Rise height (h): minimum 14 cm, maximum 20 cm. Run depth (a): minimum 23 cm, maximum 37 cm. Step formula (2h + a): 59 to 65 cm. The ideal rise for residential stairs is 17 to 18 cm with a corresponding run of 27 to 29 cm. These values produce a step formula result of 61 to 65 cm, which falls squarely in the comfort zone.
Public Building Stairs
Rise height (h): minimum 14 cm, maximum 19 cm. Run depth (a): minimum 26 cm, maximum 37 cm. Step formula (2h + a): 59 to 65 cm. The reduced maximum rise and increased minimum run reflect the need for greater safety in high-traffic buildings used by diverse populations.
Secondary and Attic Stairs
Rise height (h): minimum 14 cm, maximum 21 cm. Run depth (a): minimum 21 cm, maximum 37 cm. Step formula (2h + a): 59 to 65 cm. The relaxed limits allow steeper, more compact stairs for spaces used infrequently.
Width Requirements
The clear width of a staircase is measured between the finished surfaces of the enclosing walls, or between a wall and the inner edge of a railing.
For residential buildings with up to two dwelling units, the minimum width is 80 cm. For residential buildings with more than two dwelling units, the minimum is 100 cm. Public buildings require a minimum of 125 cm, though specific building types may require more (for example, schools and hospitals often require 150 cm or wider).
These are minimum values. For comfortable two-person passing, a width of at least 100 cm is recommended even in single-family homes. Staircases narrower than 80 cm may only serve as secondary access routes.
Handrail Requirements
DIN 18065 requires handrails on stairs with more than three steps. For stairs up to 125 cm wide, a handrail on one side is sufficient. For stairs wider than 125 cm, handrails must be provided on both sides. In public buildings, stairs wider than 250 cm require an additional intermediate handrail.
The handrail height, measured vertically from the nosing line, must be at least 90 cm. For stairs where the fall height exceeds 12 meters, the minimum increases to 100 cm. Handrails must be graspable, with a cross-section that allows a secure grip (typically a round or oval profile with a diameter of 35 to 45 mm). Handrails must extend at least 30 cm beyond the top and bottom steps.
Headroom Requirements
The minimum headroom above any point on the stair is 200 cm, measured vertically from the nosing line to the underside of any overhead obstruction (ceiling, beam, or the underside of the flight above in multi-flight stairs). This 200 cm applies to all stair categories.
In practice, achieving adequate headroom often requires careful coordination between the stairwell opening size and the stair geometry. A common problem in renovations is that the existing stairwell opening is too small, resulting in insufficient headroom above the lower steps. The solution may involve enlarging the opening, which requires structural modifications.
Winding Steps (Gewendelte Stufen)
DIN 18065 permits winding steps in all stair categories but imposes specific requirements. The run depth of winding steps must be measured along the walking line, which runs at a distance of two-thirds of the stair width from the inner edge (or at a maximum distance of 40 cm from the inner edge for stairs wider than 120 cm).
At the narrowest point (the inner edge), the tread must be at least 10 cm wide. At the walking line, the run depth must comply with the standard minimums (23 cm for residential, 26 cm for public). At the outer edge, the tread should not exceed 40 cm to prevent an unnaturally long step.
The number of winding steps should be kept to a minimum to maintain safety. DIN 18065 recommends that winding sections be limited to 90 degrees (quarter-turn) or 180 degrees (half-turn) per flight.
Landings (Podeste)
Landings serve as rest points and directional changes in multi-flight stairs. DIN 18065 requires that landing depth (measured in the direction of travel) be at least equal to the clear width of the staircase. For residential stairs with an 80 cm width, the landing must be at least 80 cm deep. For public stairs at 125 cm width, the landing must be at least 125 cm deep.
Doors opening onto landings must not reduce the required clear width. This means the door swing must be accounted for in the landing dimensions, a point frequently overlooked in residential planning.
Lighting and Visibility
While DIN 18065 does not specify exact lighting levels (these are covered by other standards), it does require that stairs be adequately illuminated for safe use. In practice, this means both natural and artificial lighting should be provided, steps should be clearly visible and distinguishable from one another, and nosings should contrast visually with the tread surface to prevent missteps.
Many modern building codes and accessibility guidelines go further, requiring illuminated nosing strips, consistent lighting without harsh shadows, and emergency lighting for stairs in public buildings.
Compliance and Enforcement
DIN 18065 is referenced by all German state building codes (Landesbauordnungen), making it legally binding for new construction and major renovations. Building inspectors check stair dimensions during the approval process and during construction inspections.
Non-compliant stairs may result in denial of the building permit, orders to modify or rebuild the staircase, liability issues in case of accidents, and reduced property value. For existing buildings that predate the current version of the standard, there is generally no obligation to retrofit unless a major renovation triggers compliance requirements. However, it is always advisable to bring stairs as close to current standards as practical when renovating.