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Local Land Use Regulation of Manufactured Housing

This page provides an overview of local government regulations and limitations in Washington State related to manufactured housing.


Manufactured housing today is quite different from the mobile homes of the past. "Mobile homes," as they are commonly thought of, are no longer being built, and "manufactured housing" has taken their place.

Manufactured housing is much more like traditional site-built housing than was the traditional mobile home. The manufactured housing industry contends that there is no appreciable difference between the two. Being generally less expensive than site-built housing, manufactured housing can provide viable housing opportunities for low income families.

Local Government Regulatory Authority

State and federal laws limit local government regulation of manufactured housing. Local governments may not enact construction, safety, and energy standards that are stricter than those established the Department of Housing and Urban Development (HUD) since Congress passed the National Manufactured Housing Construction and Safety Standards Act of 1974. 

In an effort to provide for affordable homeownership and rental housing, the state legislature since 2004 has required cities and counties to regulate manufactured homes built to federal manufactured housing construction standards no differently than they regulate other types of homes. (See RCW 35.21.684RCW 35A.21.312, and RCW 36.01.225.) Previously, Washington cities and counties seemingly had the authority to regulate the location of manufactured homes through zoning and even to ban them entirely.

Nevertheless, cities and counties may under this legislation require that that these manufactured homes: (1) be new manufactured homes (but see below); (2) be set on a permanent foundation; (3) comply with any local design standards that may apply to all other homes in the neighborhood in which the manufactured home is to be located; (4) be thermally equivalent to the state energy code; and/or (5) otherwise meet requirements for a "designated manufactured home" in RCW 35.63.160. (Because a "designated manufactured home" under that definition is one that includes at least two sections, cities and counties may still regulate "single-wide" manufactured homes differently than other types of homes.)

In 2008, the legislature passed further restrictions providing that cities and counties may not prohibit a mobile or manufactured home from locating in an existing mobile home park or manufactured housing community (existing before June 12, 2008) based on the age or size of that mobile or manufactured home. Local jurisdictions are still permitted to place age and dimension criteria on manufactured housing that is sited outside of mobile and manufactured housing communities, or on housing to be sited in new mobile home parks or manufactured housing communities.

The 2009 legislature added a further limitation on the authority of cities and counties regarding manufactured/mobile home communities. Cities and counties may not have an ordinance that prevents the entry or requires the removal of a recreational vehicle used as a primary residence in manufactured/mobile home communities. However, cities and counties may enact requirements that utility hookups in manufactured/mobile home communities meet state and federal building code standards for these communities and that a recreational vehicle contain both an internal toilet and an internal shower (unless the manufactured/mobile home community provides toilets and showers).

Many local manufactured housing ordinances in this state have been on the books for a number of years and do not necessarily reflect the current state of the law or of the industry. The Washington Manufacured Housing Association has developed "model" regulations for local governments to adopt for the purpose of complying with SB 6593. See Documents below. The model regulations do not, however, address the 2008 or 2009 legislation.


  • Federal - U.S. Code, 42 U.S.C. § 5403
  • RCW 35.21.684 - Authority to regulate placement or use of homes - Regulation of manufactured homes - Issuance of permits - Restrictions on location of manufactured/mobile homes and entry or removal of recreational vehicles used as primary residences
  • RCW 35A.21.312 - Authority to regulate placement or use of homes - Regulation of manufactured homes - Issuance of permits - Restrictions on location of manufactured/mobile homes and entry or removal of recreational vehicles used as primary residences
  • RCW 36.01.225 - Authority to regulate placement or use of homes - Regulation of manufactured homes - Restrictions on location of manufactured/mobile homes and entry or removal of recreational vehicles used as primary residences
  • RCW 35.63.160 - Regulation of manufactured homes - Definitions
  • RCW 35A.63.145 - Prohibitions on manufactured homes - Review required - "Designated manufactured home" defined
  • RCW 35A.63.146 - Manufactured housing communities - Prohibitions of code city due to community status as a noncomforming use
  • RCW 35.63.161 - Manufactured housing communities - Prohibitions of city due to community status as a nonconforming use
  • RCW 43.22.340 - 43.22.495

Model Regulations

  • "Model" Regulations (Single-Family Homes; Manufactured Homes), Washington Manufactured Housing Association, 2004 - These model regulations, offered from an industry association perpsective, are still useful, although they predate the 2008 and 2009 statute amendments.

Court Decisions

  • Washington Manufactured Housing Ass'n v. Public Utility District No. 3, 124 Wn.2d 381 (1994) - Connection charge not pre-empted

    A public utility district's new facility charge for connecting electricity to electrically heated homes that do not meet certain energy efficiency standards does not impose a construction standard preempted by section 5403 of the National Manufactured Housing Construction and Safety Standards Act of 1974 (42 U.S.C. § 5401 et seq.) if the charge covers only the actual costs incurred by the district in providing new, less efficient homes with electrical power. Also, of interest here, the state supreme court, in dicta, noted that it is "clear that zoning laws that ban manufactured housing or limit them to certain areas are not preempted if they are silent as to construction or safety standards." This is still an important case, although subsequent legislation (SB 6593) eliminated local government ability to regulate the siting of HUD-compliant manufactured housing differently than other types of homes.

  • Lawson v. City of Pasco, 168 Wn.2d 675 (2010) - Recreational vehicle regulation

    Lawson allowed recreational vehicles to park in his residential mobile home park, contrary to a city ordinance. Lawson maintained that the Manufactured/Mobile Home Landlord-Tenant Act, ch. 59.20 RCW preempted the city ordinance because the state law authorizes, if not requires, recreational vehicles used as a primary residence to be allowed in mobile home parks. A divided supreme court affirmed a decision of the Court of Appeals, a decision that upheld the city ordinance. While the state legislature intended to act in the field of regulating mobile home park landlord-tenant relationships, it did not wholly preempted local action in this field. The legislature expressly conferred concurrent jurisdiction to local municipalities in the field of regulating landlord-tenant compliance with ordinances; the state act did not preempt the local ordinance. The court also found that the ordinance's operation did not conflict with the state law; each could operate distinctly without inconsistency. The ordinance was not unconstitutional. (Subsequent to the Court of Appeals trial on this matter, state law was changed; the city would not now be able to prohibit the RV from the mobile home park. The Supreme Court did not consider the effect of the 2009 legislation (EHB 1227 codified in RCW 35.21.684; RCW 35A.21.312 and RCW 36.01.225) that was enacted after it accepted the case for review.)

Examples of Local Codes

  • Anacortes Municipal Code Sec. 17.54.100 - Manufactured home - Addresses SB 6538
  • Black Diamond Municipal Code Ch. 18.90 - Manufactured Housing – Clearly organized code addresses SB 6538 and SSB 5524
  • Edgewood Municipal Code Sec. 18.100.90 - Manufactured homes on individual lots - Addresses SB 6538
  • Lacey Municipal Code - Directly addresses SB 6538, SSB 5524, and EHB 1227 
  • Marysville Municipal Code Ch. 22C.230 - Mobile Home Parks - Updated 2011 - Addresses SB 6538 and EHB 1227 and does not appear to be inconsistent with SSB 5524
  • Mukilteo Municipal Code Ch. 17.76 - Manufactured Home - Addresses SB 6538
  • Ocean Shores Municipal Code - Addresses SB 6538 and SSB 5524 
    • Sec. 17.16.020 - R-1 Zone - Single-Family Residential, Permitted uses
    • Sec. 17.16.070 - R-1 Zone - Single-Family Residential, Regulations for manufactured homes
    • Ch. 17.26 - R-6B Zone - Mobile Home and Manufactured Home
    • Ch. 17.27 - R-6C Zone - Manufactured Home-Double-Wide or Larger 
  • Pierce County Code - Addresses SB 6538 and SSB 5524 and definition sections address EHB 1227 
    • Ordinance No. 2010-7 - Addressing the Placement of Recreational Vehicles in Mobile Home Parks, passed 04/06/2010
    • Title 18, Sec. 18.25.030 – Definition of Mobile Home Park
    • Title 18A, Sec. 18A.33.210(D) – Mobile Home Park -Description of Mobile Home Park as a residential use category
    • Title 18A, Sec. 18A.38.050(E) – Temporary Occupancy of Recreational Vehicle, Travel Trailer or Tent
    • Title 18J, Sec. 18J.15.200 – Mobile Home Parks – Design standards
    • Title 18J, Sec. 18J.15.210 – Recreational Vehicle Parks – Design standards 

Last Modified: April 02, 2021