Escape stairs - slope and step depth are required

For an escape staircase, the dimensions are initially prescribed by the building supervision exactly. The most important data are, for example, in the staircase standard or in the workplaces ordinance. Both the width of the stairs and the depth of the steps are exactly prescribed. What gradient an escape stairway must have, we show here.

Necessary stairs

The construction law refers to the escape and fire stairs as a legally required staircase. A distinction is made between general buildings and residential buildings with no more than two residential units. The houses are far from being as strict as the other general buildings.

Gradient and step depth

  • legally required stairs - at least 14 / at the most 19 centimeters slope
  • legally required residential staircase - at least 14/20 centimeters maximum slope
  • Legally necessary stairs - at least 26 / maximum 37 centimeters of landing depth
  • legally required residential staircase - at least 23 / at most 37 centimeters in depth

The width of the residential staircase can also be significantly lower than the prescribed minimum width of one meter of the common staircase. In the residential buildings only a width of 80 centimeters is required.

Additional stairs

However, in the case of the additional stairs, which are not considered as necessary stairs, the regulations are the same in general buildings and in residential buildings. The additional staircase must not be less than a width of 50 centimeters.

  • additional stairs - at least 14 / at the most 21 centimeters slope
  • additional stairs - at least 21 / maximum 37 centimeters of landing depth

Other regulations

However, other regulations may require stricter stair planning. The sales place ordinance or the workplace regulations provide special measures especially with regard to the width of escape stairs. However, some special regulations also limit the slope and the depth of the steps of an escalator even further.

Example prescribed width according to workplace regulations

  • Stair width 87.5 centimeters - catchment area up to 5 persons
  • Stair width 100 centimeters - catchment area up to 20 persons
  • Stair width 120 centimeters - catchment area up to 200 persons
  • Stair width 180 centimeters - catchment area up to 300 persons
  • Stair width 240 centimeters - catchment area up to 400 persons

Tips & Tricks

If the staircase is to be used as a fire escape, you can not use natural stones. These would be shattered by the combination of high heat and extinguishing water and thus do not constitute a safe staircase.

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