Reducing Glare on Building Facade by Implementing Vertical Greenery Shading – user-sensation vs luminance-measurement

Abstract

The user of high-rise office building usually feel discomfort glare because of high luminance from glass facade. This experimental research has an objective to find out how vertical greenery can reduce the sensation of glare. Using here a cubicle that represent one person workstation in 2m x 4m x 3.45m dimension with opening from clear glass, WWR 50%. The base case was the condition without vegetation compared to condition with Vernonia elliptica plant LAI 0.75 and LAI 1.5 which implemented as shading. The result found that vegetation LAI 1.5 can reduce luminance 54.3-56.1% compared to without vegetation. The sensation of glare from Uncomfortable becomes Perceptible (for direct light); from Perceptible-Acceptable becomes Imperceptible-Perceptible (for diffuse light). Vegetation LAI 0.75, for direct light, can reduce luminance 35.3-53.6% compared to condition without vegetation. The glare sensation vote becomes Acceptable. Whilst for diffuse light, although the luminance measurement was increase because of the reflected glare from surroundings, the natural aesthetic and green colour of leaves was relaxing, so that the sensation of glare still at the same vote, between Perceptible-Acceptable compared to without vegetation. This result proof that for biotic shading, besides the quantitative, the qualitative variables play the role.