This is a public building and there can be no presumption as to the capability of the wheelchair user or indeed any other impairment or disability of visiting members of the public. A general "PEEP" in the circumstances described would be nonsensical. It is noticeable from the above posts that there is a widespread presumption that transfer to an evac chair or ski-pad would be physically possible. The inescapable conclusion is surely that public buildings must provide for safe means of access AND egress which do not discriminate?