A commercial roof can put sunlight to work in two ways. PV panels generate electricity, while rooflights introduce natural light, reducing the need for electric lighting. For large-span industrial and commercial buildings, daylight also supports the people working below. Light changing throughout the day connects occupants with the outside world and supports a healthy body clock. Daylight also improves alertness and concentration. Spaces well-lit with daylight are associated with better staff retention and reduced absenteeism. Sufficient exposure to daylight is also believed to support long-term health and wellbeing. There are property benefits too, with good daylighting shown to increase asset value and space utilisation.
For non-residential buildings, effective daylight provision typically requires rooflights across 10-20% of the roof area. The right balance between rooflights and PV depends how the space is used, the positioning of rooflights and the other equipment the roof needs to accommodate. In large-span buildings, daylighting performance is directly related to the proportion of roof allocated to rooflights.
Planning rooflights and PV together helps make the most of the available space and allows the needs of the building and its occupants to shape the design from the start. www.filon.co.uk