This Study places emphasis on obtaining the distribution of the entire wall surface for measurement of the heat transfer coefficient on the outer wall surface of a building. An experiments is carried out on a smooth surfaced wall of a small building model (1.1m × l.lm × 1.1m) made of a SAT meter set up outdoors. Development of a method of obtaining the density of heat flow rate and the convective heat transfer coefficient at each part of a building using the measurements from the SAT meter, infrared radiant energy thermometer, and net pyrradiometer is attempted. As part of this study, the thermal image of a wall surface captured by the infrared radiant energy thermometer is divided into 10cm × 10cm grids, and the heat transfer coefficient is obtained from the heat balance of each area. This method shows the possibility of measuring the heat transfer distribution rate of an entire wall surface so long as multiple SAT meters can be attached to the wall of a small building whose surface is smooth while the measurement accuracy may be slightly inferior.