Class B RVs are built in a van platform. In the past they were built on passenger van chassis (right) but Eurovan chassis have become more common as their market share increases.

Class B motorhomes present several design challenges that make the cost surprisingly high. First, the RV amenities are built within the existing chassis and skin, which limits access for workers and fitment.¹⁾ Second, the available space is much smaller than on class A or class C.

The payoff is a more durable, leakproof motorhome with higher build quality.

• PRO
  • highly maneuverable, can be parked in normal parking spaces
  • best MPG of motorhomes
  • highest quality build
  • best leak resistance due to steel body
• CON
  • expensive
  • most expensive per square foot of living space
  • can be tight for 2+ people
  • limited standing space; often around 6'

Some Class B vans have dropped floor sections that may increase effective standing room.

• RoadTreks (1998 - 2003²⁾)“have a 3” deep pan between the frame rails about 5' long by 32“ wide”.³⁾. This is a drainage section for the in-aisle shower. When not in use the dropped floor has a cover so it looks like a normal floor. Taller folks may leave the pan exposed.
• Dodge Xplorer 224 models had a deeper dropped section near the side door, perhaps a foot deep.⁴⁾

These motorhomes blur the lines between large class B and small class C. They often have somewhat widened fiberglass body panels but lack the cabover sleeper that defines a class C.

• Wikipedia: Motorhome
• RVwiki.org: Class B
• Video discussion:
  • Robert Witham #11
  • Carolyn's RV Life #3