Local Jurisdiction (City or County) Mobile or Manufactured Home Installation Requirements
Does a local jurisdiction have any control over how and to what specifications a manufactured home is built?
- Yes. The local jurisdiction issuing the placement permit is required to inspect MH installations. RCW 43.22.440 requires counties and cities to enforce manufactured home installation rules and charge fees in the same manner the state building code is enforced, including site preparation.
If a manufactured home is being altered in anyway, is a special permit required?
- No. Manufactured homes are built in a factory to the Federal Manufactured Home Construction and Safety Standards, HUD Code 3280.
Does the local inspector receive a copy of the installation instructions for inspection purposes?
- Usually. Additions or changes to the home’s structure, such as installation and replacement of furnaces, wood stoves, electrical or plumbing systems, etc., are alterations to be permitted and inspected by the Department of Labor & Industries. WAC 296-150M. Please contact us for more information on alterations.
- WAC 296-150I-0380 requires installation instructions to be placed under the home and to be returned to such place upon completion of inspection.
Prior to skirting - the instructions are to be located between the I-beam and the bottom board within five feet of the main electrical feeder.
After skirting – the instructions are to be located between the I-beam and the bottom board within five feet of the access opening.
Can the local jurisdiction set special installation requirements?
Can local jurisdictions set special requirements for plumbing, electrical, or smoke detectors included in the home’s construction?
- Yes, according to WAC 296-150I, Sections 0300 and 0340, local jurisdictions may impose requirements for:
Installation of homes in floodplains;
Homes installed in hazardous areas
Requirements for earthquake protection
- Frost-line depth
Automatic sprinkler systems for fire protection
- Local snow and wind load requirements. NOTE: All structures in the jurisdiction must be required to meet the same requirements and options for meeting those requirements must be given.
Example: According to WAC 296-150I-0300, if the local roof snow load requirement is set at 50 psf, the local jurisdiction may require the home to have a ramada, snow removal plan, or some other option – the jurisdiction may not require the home to be built with a 50 psf roof load.
Who has jurisdiction over auxiliary structures such as carports, garages, etc?
- No. Plumbing systems, electrical systems, and smoke detectors are covered by the Federal HUD Code and are designed and built in the factory according to the HUD Code. The HUD Code does not cover plumbing and electrical outside of the home’s construction, such as electrical and plumbing supply to the home site.
Is the local jurisdiction required to verify that testing of water lines, waste lines, gas lines and electrical systems has been performed?
- Auxiliary structures are built to the building code in effect at the time and governed by the local jurisdiction. To avoid requiring an alteration permit and inspection by L&I, they must be self-supporting and not use any of the mechanical systems of the home. They may be flashed to the home. Questions regarding whether a building is an auxiliary structure vs. alteration may be directed to the Department of Labor & Industries, Factory Assembled Structures.
May the local jurisdictions require a specific foundation design or anchoring method be used?
- Yes. If the instructions used to install the home require testing of a particular system, WAC 296-150I-0310 requires the local inspector to verify that the individual installing that system has performed the test.
Can local jurisdictions adopt additional requirements to protect manufactured homes in hazardous areas?
- No. WAC 296-150I in Section 0300 (2)(a) prohibits local jurisdictions from dictating a foundation design and construction which is built according to either the manufacturer’s installation instructions or a design created by an engineer or architect licensed in Washington. The WAC in Section 0310 (c) states that local jurisdictions may not prescribe anchoring methods.
- Yes. WAC 296-150I-0340 (2)(b), local jurisdictions may set a requirement for earthquake protection. Many professionally designed earthquake resistant systems exist on the market today.
For more information:
RCW 43.22 Sections 335-495 - Manufactured/mobile homes, factory-assembled structures. (apps.leg.wa.gov)
RCW 43.22A - Mobile and Manufactured Home Installation. (apps.leg.wa.gov)
WAC 296-150I - Manufactured Home Installer Training and Certification Program, Installation Code. (apps.leg.wa.gov)
WAC 296-150M - WA Manufactured Home Code. (apps.leg.wa.gov)