A barn raising, also historically called a raising bee or rearing in the U.K., is a collective action of a community, in which a barn for one of the members is built or rebuilt by members of the community. Barn raising was common in 18th- and 19th-century rural North America. A barn was a necessary building for any farmer. Yet a barn was also a big and expensive building. Building a farm needed many people than a typical family could provide. Barn raising addressed the need by getting members of the community, unpaid, to help in the building of their neighbors' barns. Because each member was entitled to recruit others for help, the favor would eventually return to each participant.
One or more people with experience or with specific skills are chosen to lead the project. Young people helping for the first time have watched many barn raisings and know what is expected of them.