Abstract
Cooling load of building can be reduced, when solar reflection of roof surfaces is kept to be high. Such high reflective roof is called as “Cool Roof”. The cool roof is also expected to be one of countermeasures of heat island phenomena, because cool roof reflects solar radiation and prevents heat storage of urban surfaces. The cool roof has a private benefit and a public one. The former is reduction of air conditioning cost and the latter is decrease of urban temperature. This paper focuses the private benefit which is depends on seasons and areas. The private benefit is difficult to be recognized precisely without special knowledge so that simple evaluation system of cool roof is studied in this paper. The system can inform the building owner of the private benefit, and they can decide to apply it or not appropriately.
