This is to propose the measure of dissimilarity on room layout patterns. The key concept is to measure it with the distance between two patterns located by the normalised vector which represents the given layout characteristics named as room association vector. Here three types of vector are presented. Each component takes 1) binary value according to the presence of edge in adjacency graph of the given pattern, value of 2) sum of the mean first passage time for going and returning, or 3) number of steps required for the shortest path, between every pair of vertices.