Until recently, makers of buildings had little choice but to respond directly to local daylight conditions in order to gather or control daylight. In regions where there are extreme daylight conditions, the highest and lowest latitudes for example, architects continue to generate insightful daylighting strategies, approaches that often lead to eloquent spatial and formal ideas. Happily, these responses turn out to be more than local idiosyncrasy and are found to be widely relevant, even in mild, middle latitudes.

Meaningful and sense-rewarding architecture is a product of gathering local daylight and the use of that knowledge to generate architectural space. Our most accomplished architects have always known this and have used their understanding of the sky to receive daylight, organize space, bring coherence to buildings, select materials, and invest architecture with meaning. Appropriately daylighted space generates its own interior light, a kind of light that can only happen in that place in the world. In this way, daylight helps us develop meaningful architectural form. Gunnar Asplund’s design for the Stockholm Public Library is one such example of careful thinking about how a building is daylighted and how meaningful space is organized. Asplund’s understanding of daylight, his lifelong interest in the use of the ceiling as a sky, and his engagement of the Nordic sky to design the library’s lending room, resulted in his substitution of a flat ceilinged cylinder for his first proposal, a glazed dome over that space. Observers have generally favored a functional and economic explanation for this change. This is reasonable, as far as it goes, but it is not the whole story. Asplund himself specifically cited his interest in illumination with clear daylight as the motive for this refinement. Additionally, the flat ceiling and the tall windows in the drum’s walls control sun and daylight better than the glazed dome. This is not just because the great expanse of glazing was eliminated or due to the availability of clear glass for the windows. The white, plastered drum walls provide substantially more diffusing surface and, as our studies show, better distribute the low-angle sun and skylight – Nordic light. These decisions have never been fully recognized or investigated. The library, completed in 1928, offers Stockholm “illumination” in two senses. It admits daylight to the very center of the building, the lending room where the book collection resides, and, as Sweden’s first open-shelf library, the general public is given access with only limited supervision, to the world’s knowledge, the other kind of enlightenment. The windows encircling the lending room recognize this. It is these openings to the Nordic sky and its “midnight sun” that enable the space to be daylighted virtually twenty-four hours a day, on at least a few days every year – even if we are not always there to appreciate it. In this manner, the lending room, at the center of the library and in a building in the center of the city, is illuminated by knowledge and light from around the world.

Martin Schwartz is an architect, Associate Professor, and Associate Chair of the Department of Architecture at Lawrence Technological University in Detroit, Michigan, USA. His research concerns daylight and its broad influence on architectural and urban design. In 1991-1992, Martin was the Willard A. Oberdick Fellow at the Taubman College of Architecture and Urban Planning at the University of Michigan and, in 1994, he was the Frederick Charles Baker Distinguished Professor in Lighting at the Department of Architecture at the University of Oregon. He was guest Architect-in-Residence at the Department of Architecture, at the Cranbrook Academy of Art in 2004. Martin recently presented a research paper, “Form and Performance: Daylight as a Generator of Space and Form in Jorn Utzon’s ‘Can Lis’ at the Fourth International Utzon Symposium in Sydney, Australia, in 2014. He writes a blog about daylight, Architecture in the Light of Day, at www.architectureinthelightofday.blogspot.com. He is the author of the book, Gunnar Birkerts: Metaphoric Modernist, published in 2009.