This paper examines the possibility of constructing the district heating and cooling facilities in the central area of built-up areas in Saitama Prefecture in terms of heat load density as an examination from the viewpoint of the present heat demand. As the data of total floor area for each use of buildings were not made by local governments. I made the data of every 100m square area in the whole area of seven major commercial districts in the prefecture. By multiplying the data by the amount of energy consumption per 1m^2 of floor for each use, I measured the heat load density of each district. I made it clear that the heat load density of some 100m square areas in each district are high though the values of the restriction of floor area ratio are almost same.