DIN 18065
The principal German standard for building stairs.
DIN 18065 'Building stairs — Terms, measuring rules, main dimensions' is the most important standard in German stair construction. It defines all relevant technical terms, establishes measurement and calculation methods and specifies minimum and maximum dimensions for rise, going, stair width, railing height and headroom. The standard distinguishes between required stairs (with stricter requirements) and non-required stairs (with relaxations). Every stair builder and architect must know and comply with DIN 18065.