Shade-Z: An extension for static solar shading in building information modeling

Proper sizing and location of widows is crucial for creating adequate daylight conditions indoors. However, often windows are also a source of excessive solar gain and glare which have negative impacts on user comfort and well-being, and the energy efficiency of a building. The development of daylight simulation and shading optimization tools date back to the 1970s. However, none of these tools can manage naturally free-form buildings with free-form windows. This paper presents Shade-Z (SZ): A design support tool for architects to use for free-form architecture in early stages of design for improved protection from the excessive insolation. The user provides the shell of a virtual model of a building with geographical location (including time zone), and shading periods of the year and days. SZ automatically detects the window aperture and in a series of logic operations on sunbeam solids creates a static shading. SZ blocks completely undesired parts of the direct sunlight, the so called high sun positions, and allows the desired parts that is at the low sun positions. The methodology is explained and illustrated with an example of a free-form building with a free-form window placed in Warsaw, Poland. The currently functional version of SZ is programmed in Mathematica. However, in order to reach the architectural audience, it is being implemented in Building Information Modeling (BIM) using parametric modeling and scripting.