El Cajon, CA Accessory Structures: Tiny Homes (2026)

230 defines a movable tiny home (MTH) as a transportable dwelling unit built to recreational-vehicle standards that must be licensed and registered with the California DMV. The city treats an MTH strictly as a type of accessory dwelling unit, not as a standalone residence: it is permitted only in residential zones, must sit to the rear of the primary dwelling, and must meet the same location and parking standards that apply to any other ADU. Before placement, the owner must secure an Administrative Zoning Permit confirming the unit meets every general requirement in the section.

The unit cannot move under its own power and cannot exceed the size California law allows for movement on public highways. Floor area must fall between 150 and 430 square feet, and the unit must provide independent living facilities separate from the main house. It must be hooked up to water, sewer, and electric utilities rather than operating off-grid, and it must meet National Fire Protection Association standards for recreational vehicles, carrying a certification label showing compliance. Design rules layer on top: exterior cladding cannot be single-piece composite, laminate, or interlocked metal sheathing; windows must be at least double-pane with trim and no radius corners; at least half the roof area needs a slope of 2:12 or more to drain over the edge; HVAC equipment must be built into the structure rather than roof-mounted; slide-outs and tip-outs are barred; and the undercarriage, wheels, axles, tongue, and hitch must be concealed, with the unit resting on leveling or support jacks over a paved surface. Placement is barred in a Very High Fire Hazard Severity Zone unless the fire marshal signs off with added fire-protection conditions.