Virtually any type of vehicle can be converted into a motorhome, though vans and buses are some of the most commonly used platforms. Vans and minivans often use roof extensions or pop-up sections to increase headroom when these vehicles are used as motorhomes. There have also been smaller car motorhome conversions that also use pop-up sections, though these are less common. Buses typically have more than enough room to be converted into a motorhome with as many different modern amenities as the owner desires. Motorhome conversion companies can take stock vehicles and modify them, but individuals can also purchase vans or buses to create their own motorhome conversions.
Most commercially available motorhomes are built on incomplete vehicle units. The process typically involves a vehicle manufacturer providing a bare frame and drive train unit to the coach manufacturer, though these units will sometimes come with an attached van or truck cab. These motorhomes are built from the frame up by the coach company. A class C motorhome will typically have a van or truck cab with an aftermarket coach unit behind it, while class A units retain only the frame, drive train, and sometimes the steering wheel and instrument cluster of a stock vehicle.
Motorhome conversions are typically built out of a stock vehicle rather than a frame, drive train, and cab. This results in most motorhome conversion units retaining the exterior profile of a stock vehicle, which can make them more aerodynamic and easier to park. Some conversion companies have turned cars into very small motorhomes by having the back end expand in the same manner as a tent trailer. Smaller motorhome conversions are more commonly made out of vans.
Some motorhome conversion companies perform each job to order, but others have a yearly slate of models like any other vehicle manufacturer. These vehicles are sometimes referred to as conversion vans, camper vans, or class B motorhomes. Large cargo vans will often have a raised, solid roof and a lowered floor to allow for easier movement through the converted motorhome. Smaller profile vans can have a top that pops up with either solid or flexible sides.
The other main type of motorhome conversion uses a bus as the base platform. Some high end motorhome companies use large diesel buses as their conversion platform, though it is possible to convert just about any type of bus. The main benefits to using these vehicles as motorhome conversions are that the diesel engines and heavy duty transmissions are often well suited to the extra weight added by a motorhome conversion, and there is typically plentiful interior space. Diesel bus conversions are some of the largest motorhome conversions.
