1.9.4 Design Guidelines
Several independent authorities publish guidance material and set the criteria for best practice in the profession.These are the Chartered Institution of Building Services Engineers (CIBSE), UK and the Illuminating Engineering Society of North America (IESNA), USA. As an example, CIBSE has published its Lighting Guides on Daylighting and window design, and IESNA has published a standard on approved method: IES Spatial Daylight Autonomy (SDA) and Annual Sunlight Exposure (ASE) (IESNA, 2013), which describes a new suite of metrics of daylighting performance in an existing buildings and new designs, from concept to construction documents.
Several established and much-used methods of assessing, rating, and certifying the sustainability of buildings, such as LEED (Leadership in Energy and Environmental Design), BREEAM (Building Research Establishment Environmental Assessment Methodology), and DGNB (Deutsche Gesellschaft für nachhaltiges Bauen), make recommendations for daylight as part of their assessment schemes. Overall, daylight factor is the most common indicator in most of them, but the calculation methods and benchmarks are different. Apart from daylight factor as an indicator, a view to the outside, glare control, and illuminance levels are frequently used parameters for describing visual comfort.