NonePrefab modular homes are known as such because they are constructed using three-dimensional boxes or modules. These modules are nearly complete when they come off the assembly line. The finished home is set together by connecting these individual modules. The number of modules used in a single home depends upon the size of the home being built. Hence there could be two, three or even four modules that make up one single home. Roofs on these homes are usually hinged to allow for easy transportation. Different designs in roofs can also be made to order.Prefab modular homes are built in a controlled environment inside factories. This reduces the time and effort involved in building a home on site. Though prefab modular homes have a certain kind of prejudice associated with them, there is no denying the fact that the conditions under which they are manufactured ensure better quality control and a greater number of inspections. This is also the reason there are fewer instances of vandalism or damage from the weather. Prefab modular homes are also accompanied by a warranty though the terms of the warranty may vary depending upon the manufacturer.These prefab modular homes must be in accordance with state and local building codes. The Building Officials and Code Administrators National Building Code is the one most manufacturers revert to.  Plans need to be approved by local authorities before the construction of the home commences. Approval by third party inspectors follows this before certification is issued. After approval and certification of the design, only minor changes can be made. If more changes are required the procedure will have to be repeated all over again.  This is one reason why many manufacturers of prefab modular homes offer very few design choices.Most of these homes also offer living space of less than 2,400 square feet each. Though the homes can be customized as per buyer requirements, it often proves economical to stay with the design offered by the manufacturer. The manufacturers sell the completed homes to dealers who in turn find consumers. As a buyer you will need to evaluate and study the contract and the warranty that go with your home. The usual warranty period will be of a year or so and manufactured components will be covered under it. Last but not least make a checklist of all the things you need to make sure your home has.