This paper discusses a design method for calculating pedestrian movement developed by two persons and provides an egress model based upon this work for the evacuation of multistory buildings via staircases with regard to real evacuation tests in high rise office buildings. Futhermore, it briefly compares its predictions with regulatory requirements on means of escape. En matematisk modell redovisas med tabeller och diagram för utrymning, utrymningshastighet, flöde mellan våningar, flöde i korridorer, antal personer m.m.