Daylight, urban density, and the role of regulation

If daylight guidelines were strategically implemented within building regulations, more naturally lit cities would evolve.

By Arup November 9, 2016

For many centuries, humans have designed buildings to make the best of the elements and resources around them: resisting the wind and the rain while taking advantage of the sun’s heat and light. But in modern cities, design is driven by a more complex agenda, with a strong emphasis on commercial value, leading to cities full of taller, more densely packed buildings. I believe that if daylight guidelines were strategically implemented within building regulations, more naturally lit cities would evolve.

The tall glass and steel towers that dominate the skylines of New York, Hong Kong, Sao Paulo, or New Delhi not only often make poor use of daylight, but they also cause secondary issues. Strong wind effects are amplified by buildings’ proximity and height, and overheating and overshadowing are other common problems. As a result, the job of urban planners has become more focused on mitigation of these problems, rather than applying regulations to work with and welcoming natural environmental factors.

Geometrically speaking, the more spread out a city is, in terms of lower building heights and greater distance between buildings, the more daylight can be harvested. Consequently, the more concentrated and dense a city is, the less daylight is available for its buildings and interiors.

Electric light has made this level of urban density possible. This pivotal invention has transformed the traditional rhythm of day and night building use, making interiors usable at any hour. Once artificial light became a mass commodity, buildings could become deeper and taller environments, leaving occupants further from windows. In the era of the light bulb, design seems to have lost sight of the beneficial role played by natural daylight.

But perhaps the 20th century’s focus on highly populated buildings is no longer relevant. Modern technology, like email and video-conferencing, potentially reduces the need for high-density office environments. This raises the possibility that cities could embrace lower-rise buildings that make better use of natural light. And with improved natural daylight performance, buildings could also use the sun’s power as an energy source.

The tools and technology to achieve these goals already exist. Today’s parametric design practices allow the dynamic and interconnected aspects of a proposed design to be modeled and understood. This helps designers to incorporate natural daylight considerations relevant to the proposed location and orientation of a building, street, or site in ways never possible before.

I believe that with the right building regulations, a more strategic citywide approach to maximizing daylight could be taken. Vertical as well as horizontal surfaces (e.g., façades and rooftops) have a vital role to play. Regulatory encouragement for innovations like bio-reactive facades (where sunlight activates natural photosynthesis to provide power and heat) and solar panels would encourage building design that emphasizes natural daylight’s value. This could change the visual experience of our cities dramatically in the coming decades.

-Paula Longato is lighting designer at Arup. This article originally appeared on Arup Thoughts. Arup is a CFE Media content partner. Edited by Joy Chang, Digital Project Manager, CFE Media,