Prior to inviting workers to return to office buildings that have been abandoned during the coronavirus crisis, companies should explore ways to boost their buildings’ defenses against the disease, say John D. Macomber, senior lecturer at Harvard Business School, and Joseph G. Allen, a professor of Harvard’s T.H. Chan School of Public Health, who have co-authored the book "Healthy Buildings: How Indoor Spaces Drive Performance and Productivity." After all, buildings that don’t bring in enough fresh air can put employees at greater risk of getting sick and can also reduce worker productivity. In a post-COVID-19 world, a healthy building—complete with improved ventilation and air quality, plus new technologies like touchless elevators and sinks—will be seen as the first line of defense against the disease.