A kit home contains prefabricated components put together on site by the contractor. This type of home is a permanent structure set on a solid foundation. The kit home involves a company cutting all materials for the project, numbering them, and sending them to the construction site. On site, the construction manager uses provided plans to put the home together. This type of home differs from a modular home because the manufacturer does not create modular units. Instead, they send only the pre-cut materials with plans. This house option was quite popular in the first half of the 20th century. A number of companies offered these homes to customers all over the country. The kit would arrive packed in box cars to the nearest train station. After unloading, the materials went to the building site for construction. Today, no kit home companies remain active in the United States.