The building law required width of stairs

In building law according to the valid staircase DIN 180565 stairs are subdivided into necessary and not necessary stair types. In addition, a distinction is made between a general rule for buildings and regulations for stairs in residential buildings and apartments.

Minimum widths and walking area

In general, a usable minimum running width of the stairs of one meter applies to stairs required by construction law. In residential buildings and apartments, it is eighty centimeters.

With unnecessary stairs, usually additional stairs to the main floor connections, fifty centimeters are defined as the minimum width both in general and in the living area.

For stairs in public spaces and in stairwells of apartment buildings special rules apply to the width of the stairs. If up to 150 people are expected to be users, the minimum size is set to 1.25 meters in many cases. Walking area is defined as twenty percent of the step width from the center.

Video Board: Stair Treads and Risers Building Code Update - 2012 International Building Code