There are nearly 600,000 portable classrooms across the country. These “temporary” structures are plagued with problems: poor ventilation, water intrusion, high levels of formaldehyde, and insufficient building maintenance. The problems are particularly worrisome given that recent studies have shown that poor indoor air quality can reduce cognitive performance. This grant funds a team led by Professor Kerry Kinney at the University of Texas, Austin, to construct a case study examining how “hidden spaces” in a temporary-yet-permanent building influence the indoor microbiome. Hidden spaces like ceiling plenums and crawl spaces can be important vectors for the spread of microbes indoors. Dark, moist, and infrequently cleaned, such spaces often contain high levels of contaminants, which may subsequently be spread throughout the building by drafts. Studying actual portable classrooms, Kinney and her team plan to identify where microbes and other contaminants come from and where they go within classroom and hidden spaces, and then determine how positive and negative pressurization from ventilation systems affects the microbiota and other contaminants in various parts of the portable classroom The researchers will share their findings by publishing in building science, life science, and trade journals; in web posts; and by using social media to direct readers to these postings. The team will also make presentations at national and international meetings. Both a graduate student and a postdoctoral fellow will be trained in indoor microbiome and building science studies during the research.