Concession trailer
A concession trailer is a towed trailer fitted out as a kitchen or serving stand, also called a food trailer. Sizes are named width by length in feet, such as 6x12, 7x14 or 8.5x20, and the length counts the box, not the tongue.
Trailers often give more room for the money than a step van. Concession Nation notes they're about a foot wider than step vans with taller ceilings. A Renown 8.5x20 cargo trailer is 96 inches wide inside, 78 inches tall and 23 ft 6 in long with the tongue.
Health departments generally hold trailer kitchens to the same sink, tank and plan review rules as trucks. Maricopa County, Arizona, for example, writes its mobile guidelines for a truck, trailer or unit alike. Compare the options in food trailer sizes, then try one of the trailer presets in the layout maker.