A decade ago, factories and hotels were the prime targets for adaptive reuse. Now, former offices comprise 41% of all US apartments converted during the past two years, according to RentCafe. They are also the most popular building type for future adaptive reuse projects, creating one-quarter of the 52,700 residential units expected to become available in the US in 2022 (a figure that’s up from 6,960 in 2012).