Senior people spend most part of a day in their houses. Even by day, they need an ever brighter environment than younger people do. The designer answered the need by use of metal-halide lamps and daylight-color fluorescent lamps, which achieve high performance in luminosity and durability. The designer's plan comprises three points:
(1) Supplementary lighting in daytime.
Senior citizens need more time to adjust their vision to darker circumstances when returned from outdoors. 150W metal-halide lamps and 100W compact krypton lamps are installed in the entrance; the metal-halides cast bracing light by day, while the kryptons lay soft incandescent light by night. In bedside, fluorescent wall washers provide sufficient luminance for reading books. The fixtures are carefully designed so they would not shine directly in the eyes. Shoji, papered sliding doors, is illuminated to make rooms visually bright.
(2) Concentrated lighting for high illuminance.
Senior people need three times as much illuminance as the younger. Downlights and table lamps achieve 1000lx at maximum.
(3) "At home" lighting.
It is often said that metal-halide lamps and fluorescent lamps are not very suitable for a residence's lighting source. The designer used natural, warm-colored materials for interior furnishing and avoided making the atmosphere feel chilly.
