New Study Confirms That Modernists Were Right About Sunlight – It Is the Best Disinfectant


This is how we got modern architecture and minimalism.

After the First World War, a new form of modern architecture appeared, modelled after the new tuberculosis sanitariums where they fought disease with design. They didn't have antibiotics, but they had light, fresh air and openness.

Neutra, Le Corbusier and Chareau all designed iconic houses for doctor clients around these principles. And now Noel Kirkpatrick of TreeHugger points to a new study that confirms they were right; as Supreme Court Justice Louis Brandeis noted, sunlight really is the best disinfectant. The researchers of the study, Daylight exposure modulates bacterial communities associated with household dust, built little model rooms with little model windows and then "inoculated them with dust collected from residential homes in Eugene, OR, USA." The windows were variously clear glass, UV blocking glass, UV transmitting glass, or a solid aluminum plate.

Little model rooms

Ashkaan K. Fahimipour et al/CC BY 2.0

After 90 days the dust was collected and checked. As Kirkpatrick recounts, "In the dark rooms, they found that 12 percent of the bacteria was still alive and able to reproduce, while the rooms exposed to daylight only had 6.8 percent viable dust bacteria. Rooms that received only UV light had 6.1 percent of viable bacteria."

Co-author Kevin Van Den tells NPR that, "Until now, daylighting [illuminating a building with natural light] has been about visual comfort or broad health. But now we can say daylighting influences air quality."

©. Maison Ozenfant/ Le Corbusier

© Maison Ozenfant/ Le Corbusier

Kevin Van Den should read Paul Overy's book Light, Air and Openness; he would find that architects and doctors have known for many years that sunlight had this effect, and that it has profoundly influenced modern design. It's why we got modern architecture and minimalism. Overy wrote about the basic rules of design:

Dirt and dust harboured germs that must be destroyed by fresh air and sunlight. Homes should be cleaned thoroughly every day and windows and doors opened each morning to let in the sun and air, to destroy the germs. Heavy drapes and curtains, thick carpets and old furniture with decorative features that harboured dust and microbes should be thrown out and replaced with simple, easily cleaned modern furniture and light, easily washed curtains.
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Thonet Chair ad/via

Don't give dust a place to gather. Keep furniture light and mobile and easy to clean so that sunlight can penetrate everywhere. As Mies van der Rohe noted about his tubular furniture:

It therefore promotes comfortable, practical living. It facilitates the cleaning of rooms and avoids inaccessible dusty corners. It offers no hiding place for dust and insects and therefore there is no furniture that meets modern sanitary demands better than tubular-steel furniture.
Public Domain. Lovell Health House, 1929. Credit: Department of Special Collections, Charles E. Young Research Library, UCLA.

The new study authors conclude that "architects and lighting professionals designing building facades and rooms with more or less access to daylight may play a role in influencing the microbial communities of indoor dust." Indeed, architects and lighting professionals have known this for years. In his first major book, Towards a New Architecture, Le Corbusier wrote that you should "teach your children that a house is only habitable when it is full of light and air, and when the floors and walls are clear."

This is where minimalist design came from; it is all about creating a healthy, easy-to-clean environment where dust and dirt can't hide. And this new study shows that the modernists were right about light, too.