Tiny houses on wheels are included in the definition of "occupied recreational vehicles" when inhabited and parked on a developed residential lot with a primary dwelling unit or house. "Occupied recreational vehicles" are defined in Chapter 33.260 of the Portland Zoning Code and include:
- Recreational vehicles
- Fifth-wheel recreational trailers
- Campers attached on a vehicle
- Constructed tiny houses built on a trailer with wheels
Some similar forms of accommodation are not considered as occupied recreational vehicles or tiny houses on wheels, including:
- Campers or structures that do not have wheels attached
- Accessory structures such as accessory dwelling units (ADU), detached sleeping rooms and other similar structures built on foundations
- Occupied recreational vehicles or tiny houses on wheels that are permitted as hotels, motels or recreational vehicle parks
Land Use and other requirements
- In order to remain mobile, the wheels must remain on occupied recreational vehicles or tiny houses on wheels.
- Only one occupied recreational vehicle or tiny house on wheels is allowed on a residential lot with a house, attached house or manufactured home. Up to four occupied recreational vehicles are allowed in the parking lots of religious institutions.
- Occupied recreational vehicles, including tiny houses on wheels, are not permitted on undeveloped lots.
- Occupied recreational vehicles, including tiny houses on wheels, must comply with parking requirements for recreational vehicles on residential lots. This generally means a tiny house on wheels must be parked on a paved surface if it has a motor and it cannot be located in front of the street-facing façade of the house, attached house or manufactured home.
- An occupied recreational vehicle, including a tiny house on wheels, does not count toward residential density.
- In most cases development standards for houses, attached houses and manufactured homes do not apply to a tiny house on wheels.
- A tiny house on wheels is prohibited from being used as an accessory short-term rental.
Building code requirements
Although occupied recreational vehicles are not considered buildings, there are some building code requirements related to the vehicle’s location relative to other dwelling units. These vehicles must be parked at least five feet from the primary dwelling.
All occupied recreational vehicles will be required to have electrical connections. Electrical connections must be made through a dedicated outlet on a service pedestal or on the primary dwelling, which must be a minimum 20-amp, GFCI-protected, dedicated circuit. (An electrical permit is required if a circuit is not already installed.) The extension cord connection must be with an extension cord rated for the correct voltage, amperage and load as well as for exterior use. The extension cord’s length should be adequate to maintain voltage and provide an uninterrupted connection between the vehicle and the outlet connection. Multiple extension cords may not be used.
If the occupied recreational vehicle has internal plumbing, it must be connected to potable water and sanitary sewer services.
For required plumbing utility connections:
- Water connections may be made through a campground-style faucet connection. This allows the water connection to be closer to the occupied recreational vehicle.
- Water connections may also be made through an anti-siphon hose bibb on the primary house.
- Connections from the vehicle to the hose bibb must be with a flexible hose rated for potable water.
- Sewer connections may be made through a campground-style dump station attached to the sanitary sewer line of the primary house. A plumbing permit is required for the sewer connection. A concrete pad will be needed around the cleanout dump connection.
- If the occupied recreational vehicle or tiny house on wheels does not have internal plumbing, the occupants must have access to potable water, toilets and showers in the primary house.
If the occupied recreational vehicle does not have internal plumbing, the occupants must have access to potable water, toilets and showers in the primary house.
System development charges and loan programs
- System development charges are not part of the electrical and plumbing permit costs.
- The Bureau of Environmental Services has two loan programs for the installation of sewer connections for those who qualify.
Helpful safety tips
- Create as much fire separation distance as possible between the dwelling and the occupied vehicle.
- Keep three feet between electric space heaters and belongings.
- Don’t smoke inside vehicles.
- Install and maintain fire extinguishers, smoke detectors and carbon monoxide detectors.
- Make sure propane tanks are in proper working order. Store tanks outside of the living space.
- Sewer gases can be harmful to health. If holding tanks are being used, have them serviced regularly. Check for leaks along the outside of the tank and at fittings.
- Freshwater supply tanks should be disinfected regularly and filtered before drinking.
- Make sure secure garbage and recycling containers are available and emptied regularly.
Be a good neighbor
- Be courteous with off-street parking.
- Keep noise levels down, especially at night and in outdoor areas.
- Make sure vehicles are parked legally.
- Look after pets and clean up behind them.
Enforcement of requirements
Regulations on long-term rental units
Additional property maintenance regulations (Portland City Code Title 29) may also apply if the occupied recreational vehicle is a rental dwelling unit and not occupied by the property owner.
Driver and Motor Vehicle Services (DMV) regulations
Oregon Driver and Motor Vehicle Services (DMV) regulations only apply if the recreational vehicle is being pulled or driven on a street, road or highway. Oregon DMV may register a tiny house on wheels as a camper, a travel trailer, or a park model RV, depending on its size and configuration. Please contact Oregon DMV if you have any questions about its registration requirements for tiny houses on wheels.
- Utility assistance and housing referrals: 2-1-1
- Linking property owners needing roommates with home-seekers: Metro Home Share, 971-271-5195
- Home repair assistance: Reach Community Development, 503-231-0682
- Free mediation of neighborhood conflict: Resolutions Northwest, 503-595-4890