In this paper hour-by-hour computer simulations of cooling load for a public building were carried out under local weather conditions using TRNSYS building computer simulation software. Different passive measures to reduce the cooling load were investigated. These include the envelope insulation, space ventilation, shading, glazing, artificial lighting variation, and evaporative cooling of the structure. The results show as high as 43% reductions in peak cooling load can be achieved using a combination of well-established passive cooling techniques and technologies. The significance of these results stems from the fact that they were obtained under local weather conditions, a matter of importance to building architects, designers, contractors, and builders as well as air-conditioning equipment manufacturers. Although this work was undertaken to improve the thermal performance of school buildings the results were extended to cover the summer school vacation months so that they will benefit public buildings as well.