An accessible means of egress can be defined as a ‘continuous and unobstructed way of egress travel from any point in a building or facility that provides an accessible route to an area of refuge, a horizontal exit, or a public way’ (ADA 2010).
Some international building codes detail the requirements for an accessible means of egress, including areas of refuge. Generally, where regions mandate for an accessible means of egress they will require at least one accessible means of egress for every accessible space and at least two accessible means of egress are required where more than one means of egress is required.
One can surmise that if an evacuation lift is provided, all occupants have some ability to independently evacuate a building – but when an evacuation lift is not provided, a person who cannot negotiate an escape stairway would have to wait in a safe refuge for assisted evacuation, unless friends, family or co-workers can assist them down the stairway.
The use of exit stairways, in conjunction with stairway evacuation devices (i.e. evacuation chairs) could also be a reasonable solution if an evacuation lift is not provided.