Benefits of natural light & rooflights in building design
"Light is not only an amount of energy," said Marilyne Andersen of MIT’s Department of Architecture. "It also provides us with the means to reveal spaces and volumes and interact with our environment."
Andersen and others in the Building Technology Program have been working on how to better incorporate natural light into building design, believing that light has many positive effects, including considerable financial savings in energy bills and the overall effects of natural light on health and well-being. According to their findings, natural light improves mood, and even health – by regulating human circadian rhythms, for instance. “Natural light is part of our biological needs. Intuitively, we prefer daylight to electric light,” she said.
The importance of natural light in South Africa came into focus last year when the National Building Regulations and Building Standards Act was revisited to include special focus on energy efficiency. The goal of this regulation is to reduce Green House Gas emissions by reducing operational energy use of new buildings without reducing comfort and amenity. The building orientation, roof assembly (including insulation), walls and windows would have to meet minimum requirements to prevent heat loss in winter, or heat gain during summer, in order to meet the energy efficiency targets.
Architects worldwide are making use of translucent materials, such as plastics, to light up homes, offices and warehouses. New Zealand firm Mitchell and Stout used plastic translucent to build a roof and walls resembling a sail at their eco-friendly beach house in Auckland.
Translucent materials can also electricity costs – which accounts for 25-40% of energy consumption – drastically by letting natural light through. Designers should therefore, unless there are specific over-riding reasons for artificial lighting, always assume that natural lighting during daylight hours will be the primary source of light in a new building to reduce waste. There are other benefits too: the “perfect white light” that natural lighting provides creates an atmosphere of warmth, openness and tranquillity.
According to leading consultants, horizontal rooflights prove two and a half times more light than vertical windows as they are not obstructed by trees, buildings or other structures. They also provide occupants with views of the sky and promote a sense of well-being.
Rooflighting can also be used to balance existing sources of natural light, for example, it can be added above the furthest wall from a window to even out natural light, or central rooflights can be installed to give consistent light distribution.
Rooflights can be made from any material, but polycarbonate is considered to be one of the most popular materials. It has exceptional impact resistance, high levels of light transmission, high levels of UV resistance, good fire resisting properties and a wide range of clear, tinted and opaque finishes. A co-extruded UV protective layer can also eliminate up to 95% of UV radiation. The sheet can be moulded into domes, pyramids or other shapes.
In short:
- The benefits of using natural light in building design can be felt on a human, environmental and economic level.
- Benefits to humans include improved mood, concentration and healing.
- Benefits to the environment are primarily reduced carbon dioxide emissions due to diminished reliance on artificial heating and lighting.
- Benefits to the economy include improved workforce productivity and sales, and reduced expenditure on energy for heating and lighting.
