EVALUATION METHOD OF OPTICAL ENVIRONMENT FOR BUILDING

PROBLEM TO BE SOLVED: To acquire an energy-saving effect easily, with precisely and quickly determining whether moderate indoor illuminance can be provided or not, and with saving trouble and time needed for completion of a plan, in an evaluation method of optical environment which is applied when designing a building like an office building and so on. SOLUTION: When data of a light transmittion member and a light source attached to an opening in the building is inputted (step S2, S3), spectral distribution of the light source is divided into a plurality of wave length areas (step S7-S9). An amount of energy of each wavelength area of the light source is calculated (step S10), then transmittance and reflectivity of each wave length area of the light transmittion member are calculated (step S11). Transmission quantity and reflection quantity of each wavelength area are calculated, based on the amount of energy, the transmittance and the reflectivity. These are added over the whole wave areas, then the indoor illuminance is calculated (step S12) and indicated (step S13). The precise indoor illuminance where optical characteristics of the light transmittion member and wavelength dependence of the transmittance are considered, is acquired in a moment, and is indicated so as to be easy to be seen.