Daylighting Metrics for Residential Buildings

It is now widely accepted that the standard method for daylighting evaluation - the daylight factor – is due for replacement with metrics founded on absolute values for luminous quantities predicted over the course of a full year using sun and sky conditions derived from standardised climate files. The move to more realistic measures of daylighting introduces significant levels of additional complexity in both the simulation of the luminous quantities and the reduction of the simulation data to readily intelligible metrics. The simulation component, at least for buildings with standard glazing materials, is reasonably well understood. There is no consensus however on the composition of the metrics, and their formulation is an ongoing area of active research. Additionally, non-domestic and residential buildings present very different evaluation scenarios and it is not yet clear if a single metric would be applicable to both. This study uses a domestic dwelling as the setting to investigate and explore the applicability of daylighting metrics for residential buildings. In addition to daylighting provision for task and disclosing the potential for reducing electric lighting usage, we also investigate the formulation of metrics for non-visual effects such as entrainment of the circadian system.