The Microbiome of Green Design Sustainable building practices may have unforeseen consequences for microbial communities and human health.

J as our bodies teem with microbial life, so, too, do the homes, offices, schools, and other indoor spaces where we spend the majority of our lives. Scientists across the globe are now taking a closer look at the bacteria and fungi that live alongside us. They want to better understand whether indoor microbes affect our health and whether we—through the ways we design and live in buildings— shape their communities. Researchers in this emerging field known as the microbiome of the built environment come from varied backgrounds, including architecture; ecology; evolution; and heating, ventilation, and air-conditioning (HVAC) installation. But many of them share the same goal: to design buildings to encourage microbial ecosystems that benefit human health. Considering these microbes may be especially critical for designing healthy green buildings. “Green buildings have generally focused on energy efficiency and the carbon footprint,” explains Jeffrey Siegel, a mechanical engineer who studies the microbiome of building materials at the University of Toronto. “What we can end up with is a building that is better for the world in the sense of carbon emissions but is less healthy for the inhabitants.” Research exploring the micro biome of the built environment began in earnest in the early 2000s, when the Alfred P. Sloan Foundation began recruiting scientists to join the field. The Sloan Foundation had previously funded researchers who were looking for ways to protect buildings from biological threats. The foundation and the scientists soon realized that buildings were full of microbial life—both good and bad. “It seemed that looking for the biological threats in a building was like looking for a needle in a haystack of all sorts of other things,” explains Paula Olsiewski, the program director for the Sloan Foundation’s microbiology of the built environment research portfolio. “Given that we spend 90 percent of time indoors, we thought it would be interesting to study the haystack,” she says. The Sloan Foundation has awarded $45 million in grants to ecologists, building scientists, engineers, and others in this emerging field.