Method for determining the minimum width of exitways in means of escape, TR11 (1992)
- Valid from
- Information provider
- BRANZ Limited
- Information type
- Technical recommendation
This design method was intended to be used as an alternative method for determining the minimum width of exitways in buildings.
The method presented here provided an equivalent level of safety to Approved Document C2/AS1 that was valid at the time, assuming that a common stair with a maximum pitch (slope) is used as permitted in Approved Document D1/AS1, also from that time.
The method proposed provides the additional flexibility to make allowances for the ease of use of stairs depending on their gradient. Stairs that are generously proportioned and comfortable for people to use will result in a faster flow of people and therefore faster evacuation can be achieved. In many cases, the method will allow the exit width to be less than in Approved Document C2/AS1, for a given occupant load, but without any increase in evacuation time.
The method described here is applicable to all types of occupancy or purpose group, except open grandstands and similar types of open-air stadia. In these cases the method could still be applied in principle, but the calculations would be different.