Evaluation of Dynamic Daylight Metrics, Based on Weather, Location, Orientation and Daylight Availability

Abstract

This paper demonstrates that it is possible to achieve 3 daylight credits of Leadership in Environmental and Energy Design version 4 (LEED v4) in all latitudes and orientations. This study uses a space with sidelight windows and shading devices representing a section of a typical office in a multistory building. To comply with LEED v4, the space has been simulated under different weather, location, orientation, and daylight availability conditions. Simulations were done using the DIVA-for-Rhino and Grasshopper plugins. Twelve selected locations with their vertical facades facing the cardinal directions were simulated. The design variables were window size, geometry, and optical properties of the shading devices. Findings show that to comply with the Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE) metrics of LEED v4 daylight credits, the south-facing facades require minimum shading devices in low latitude locations (0º–25º), extended shading in intermediate latitudes (25º–50º), and shading that extensively blocks the window glass in high latitudes (> 50º). In general, north-facing facades do not require shading except at equatorial locations. East- and west-facing facades at all latitudes require extensive shading devices similar to south-facing facades in high latitudes.