A computer model was developed to predict the black globe humidity index (BGHI) to simulate different resultant conditions in designing poultry buildings. The simulated BGHI values were compared to experimental measurements, obtained in a poultry facility at Viçosa, MG, Brazil, giving a mean deviation of 1.31 %. The model was then used to predict BGHI values as affected by roof slopes of 25º, 30º, and 35º, and column heights of 3.0 and 3.5 m. The results showed that BGHI can be reduced by 0.12 units per 5º increase in roof slope, or 0.10 units per 0.5 m increase in column height. The maximum reduction of BGHI, 0.33 units, was obtained when comparing the extreme conditions of 25º roof slope and 3.0 m height vs. 35º slope and 3.5 m height.