Abstract
The thermo-radiative simulation on the basis of the realistic urban geometric model has a large of calculated amount. This paper suggests a simplified numeration for simulating a few hundred square meters area, and verifies the calculations compared to accurate calculations. It is original that the simplified numeration integrates mesh elements facing same direction when energy balance of urban surface is calculated. The effectiveness of the simplified numeration is confirmed from results of the verification. Moreover, this paper considers the classification of realistic urban geometric forms according to some parameters concerning radiation heat transfer.