What should be included: Mobile or manufactured homes are built in a factory and transported to the site they occupy. Overall size is limited by what can be towed by a tractor-trailer on public highways. Single-wide mobile/manufactured homes are a maximum of 18 feet wide and 90 feet long. Double-wides are at least 20 feet wide and a maximum of 90 feet long, and are towed in two separate units that are joined together at the site. There are triple-wide and homes with four or more units, but they are less common.