Preservation efforts date from the early years of the 20th century. The first legal protection of buildings in Røros was effected in 1923. Legal protection now extends to 80 buildings. In 1936 land was purchased for the development of an open-air museum, and the first old building was moved to the site in 1947. However, the museum impetus was overtaken by a movement, dating from 1938, that led to the preparation of plans for the preservation of the town and copper works in situ .