Bacterial community dissimilarity, as measured by weighted UniFrac, a quantitative measurement (a), and unweighted UniFrac, a qualitative measurement (b), of the Flagstaff samples (similar patterns were observed across all of the cities). Bacterial community dissimilarity, as measured by weighted UniFrac, a quantitative measurement (a), and unweighted UniFrac, a qualitative measurement (b), of the Flagstaff samples (similar patterns were observed across all of the cities). Darker colors indicate that groups of samples are more dissimilar, and lighter colors indicate that groups of samples are more similar. The labels indicate the locations in the office, followed by the material type. For example, ceiling/carpet indicates the samples of carpet that are installed on the ceiling sampling plate, and investigation of the first column of panel a shows that the carpet samples on the ceiling are more similar to the carpet samples on the wall than they are to the carpet samples on the floor. John Chase et al. mSystems 2016; doi:10.1128/mSystems.00022-16