The cooling effect of various kinds of greenery cover was investigated by both experimental model and computer simulation. Four concrete roof models were constructed and different coverings were arranged for each: bare concrete, soil layer, soil layer with turf, and soil layer with ivy. Temperature profiles, including air temperature in the air space under the roof were measured along with other environmental parameters to calculate the cooling effect. A computer model to simulate the systems and to evaluate cooling load was constructed using the simulation language CSMP. The simulated results matched reasonably well with the measured ones, and the cooling effect increased with increase in leaf area per unit roof area (LAI). (C) 2000 Elsevier Science S.A. All rights reserved.