Recently, we had the good fortune to interview University of Plymouth Professor Michael Wigginton, author of “Glass in Architecture” and “Intelligent Skins”, and a leading expert on building envelope engineering about the history and science behind sustainable building design and the integration of daylighting technologies.
SL: What do you understand and teach as the principal elements of sustainable architecture. Is the effective use of daylight essential to sustainable design?
MW: In the design algorithms I have developed, daylight has been an early morphological driver, because it enabled the building interior to be used optimally, exploiting the functioning of sight to operate in the spectrum it was evolved to use, without cost, except the cost of the window. The removal of the requirement for artificial light except during the hours of darkness means that the lights can be turned off. Conventionally lighting requires ~10 Watts per square metre.
SL: How do you view the value and importance of daylight in building design – offices, schools, hospitals and residences?
MW: I think it is fundamental. It is what we have evolved to see by, and it is free. Quantification of value is hard in relation to some spheres, but all research supports the notion that our buildings should be day lit. Our eyes interpret colour best in daylight, and the whole spectral distribution inherent in the perception of form is properly interpreted.
SL: What do you consider are the limiting factors on the use of daylight in architectural design?
MW: Daylight should be considered as a fundamental characteristic of building interiors, because the human system (and the eye) has evolved to respond to it. The use of daylight was fundamental to all building design until the invention of electric light. Windows make the interiors of buildings habitable. Unfortunately they also provide views of the sky which can be hundreds of time brighter than the interior, particularly in positions back from the window. The limiting factors are the ability of designers to enable daylight to reach building interiors whilst avoiding the problems of glare. The problem for design with daylight is the depth to which daylight extends to the interior, and the resulting large external wall: floor ratio, which opuses the cost of the external wall up. This is why the search for light bending has been so important.
