Width of two metres—D3D10

Most people using stairways tend to move in easy reach of a handrail or barrier. This tendency is particularly pronounced during an emergency evacuation. The D3D10 maximum of two metres (effectively permitting a reach of one metre to either side) is considered reasonable.

Wider stairways are permitted, with more than two metres between the handrails. However, for the purposes of calculating required widths, such stairways are deemed to add no more than two metres to the aggregate required width.

Examples

If a building is required to have a path of travel to an exit with a width of four metres, a stairway with four metres of width between its handrails will not comply, as it will be deemed to only provide two metres of width. Therefore, an intermediate handrail should be provided or a further two metres must be provided by other means.