Be sure to contact Labor & Industries (L&I) to get approval for your plan before you start converting a mobile unit into a food concession unit or modify a mobile medical unit.
Portable structures are regulated by L&I for such things as electrical wiring, the water supply and waste water systems, and any mechanical systems such as gas piping or heating and cooling equipment.
It is not L&I's jurisdiction to regulate what elements you might need to satisfy health department requirements — the health department can require a hand-washing sink, for example — but it is L&I's responsibility to be sure it is plumbed correctly.
Here's the process for getting your conversion vendor unit or mobile medical unit alteration plan approved and the work inspected and approved by L&I:
The conversion vendor unit (or mobile medical unit) plans you submit for plan review must contain enough information to determine conformance with the applicable conversion vendor and medical unit codes.
Structural: Only concentrated loads of 500 pounds or more in a 16-square-foot area need to be addressed. Compliance can be accomplished by means of WAC 296-150V-0350. This would apply to units that were either built or converted from another structure as a Vendor Unit" under WAC 296-150V. If you wish to build or convert a structure into a "Commercial Coach," please contact the Department at FactoryAssembldStruc@Lni.wa.gov or 360-902-5218.
Electrical: Show the general location of outlets, lights, switches, and the main distribution panel box (this may be combined with the floor plan drawing or done as a separate drawing). Include a schedule showing what the breakers in the main panel box are, including breaker sizes and what they control. Provide electrical load calculations that show the overall electrical demand in amps. (See sample Electrical Floor Plan.)
Plumbing (Water): Show the locations of all sinks, holding tanks, and other plumbing fixtures. Include pipe sizes for water supply. Provide information on the operating pressure in the water supply system as well as the length of water piping from the inlet or pump to the furthest fixture. (See sample Water plan.)
Plumbing (Drain): Show the locations of all sinks, holding tanks, and other plumbing fixtures. Include pipe sizes for drainage, waste, and vent pipes. Show the location and size of the drainage system outlet. (See sample Drain plan.)
Mechanical: If you have gas appliances in your
commercial coach, you must show the gas piping layout and size. You will
be required to supply the BTU/H input requirements for all gas appliances.
Show the location of the gas supply inlet or tank. Provide the type of fuel
(i.e.: natural gas or propane) and the length of the piping run from the
tank or inlet to the furthest appliances. If you have a heating or air conditioning
appliance, you will have to show conformance to the state energy code on
the forms provided. (See sample Gas plan.)
See all these printable Sample Plans.
Note: Be sure to check with all local building departments where you plan to use your unit. Some building departments may not allow the use of conversion vendor units in their jurisdiction. You may be required to have a commercial coach in that jurisdiction.