Manufactured Housing in Montana
A review of the impact of Zoning Regulations


  1. Overview………………………………………………..
  2. What is a Manufactured Home?……………..
  3. City Zoning Ordinances………………………….

**** Helena……………………………………………….3.1

**** Billings……………………………………………….3.2

**** Great Falls………………………………………….3.3

  1. Code Requirements………………………………….
  2. Objectives of Zoning Ordinances…………….
  3. Appearance Comparisons……………………….
  4. Value Considerations………………………………
  5. Suggested Zoning Language……………………


The nature of Montana‚s economy creates an expanding market for affordable housing. As we move toward a more service-oriented society, average wages are falling well below national averages. With only marginal industry to provide higher paying jobs, the demand for affordable housing is here and will continue into the foreseeable future. As this downward shift occurs, we are seeing expanded efforts to provide a safer and healthier living environment. Tighter development controls are increasing costs by requiring higher levels of development that include paving, curbs and gutters, street lighting, open space, parks, landscaping, improved fire protection, advanced sewage treatment systems and dependable water supplies.  Though desirable, these amenities do not come without cost.

Decreasing wages combined with increasing land development costs create a marketing dilemma with the home in the middle of the equation. Manufactured homes have, by the nature of their method of assembly, been able to produce quality homes at competitive prices to serve the affordable housing market. As demand increases, the need for more manufactured housing will also increase. Servicing this demand will require more opportunities to locate manufactured homes in neighborhoods that provide for the needs of those that will reside there.

Land use restrictions, primarily zoning regulations, play a key role in where manufactured housing may be sited. The demand for affordable housing encourages us to re-evaluate the limitations that are placed on this type of housing and examine options to improve the opportunities to utilize manufactured housing in a manner that will best serve the market demand. This document examines the regulatory position of manufactured housing and presents information to assist those involved with zoning and land use regulation so they may better understand what manufactured housing is and how it can best be utilized to serve an increasing market.

What is a Manufactured Home?

In its most general sense, manufactured housing can mean any home built in a factory setting and installed or assembled on a home site. This definition would include trailer houses, mobile homes, manufactured homes, modular homes, and recreational vehicles that serve as residential units. Since there are significant and recognizable differences in each of these types of structures, it becomes necessary to refine the definitions so that each may be treated accordingly. Without clear definition, the difference between the types of factory-built homes leads to regulatory language that, in some instances, does not make a distinction. Though frequently referred to in the same context, manufactured housing is defined separately from „mobile homes, „trailer houses, and „modular housing. Montana Code provides some guidance in distinguishing between the various types of homes that are „manufactured off-site:

Title 15-1-101(2)(l), MCA (Taxation)
The term „manufactured home means a residential dwelling built in a factory in accordance with the United States department of housing and urban development code and the federal Manufactured Home Construction and Safety Standards. A manufactured home does not include an mobile home as defined in 61-1-501 and in subsection (1)(m) of this section, a house trailer, as defined in 61-1-501, or a mobile home or house trailer constructed before the federal Manufactured Home Construction and Safety Standards went into effect on June 15, 1976.

Title 15-1-102(2)(m), MCA
The term „mobile home means forms of housing known as „trailers, „house trailers, or „trailer coaches exceeding 8 feet in width and 45 feet in length, designed to be moved from one place to another by an independent power connected to them, or any trailer, house trailer, or trailer coach up to 8 feet in width or 45 feet in length used as a principal residence.

Title 61-1-501, MCA
„Mobile home or „house trailer means a trailer or semi trailer that is designed, constructed, and equipped as a dwelling place, living abode, or sleeping place (either permanently or temporarily) and is equipped for use as a conveyance on streets and highways or a trailer semi trailer whose chassis and exterior shell is designed and constructed for use as a house trailer but that is used permanently or
temporarily for the advertising, sales, display, or promotion of merchandise or services for any commercial purpose except the transportation of property for hire or the transportation of property for distribution by a private carrier.

Title 61-1-513(1), MCA
„Manufactured home means any residential dwelling built in a factory in accordance with the United States department of housing and urban development code and the federal Manufactured Home Construction and Safety Standards.

Title 76-2-203(6), MCA (municipal and county zoning statutes)
… „manufactured housing. means a single-family dwelling, built offsite at a factory on or after January 1, 1990, that is placed on a permanent foundation, is at least 1,000 square feet in size, has a pitched roof and siding and roofing materials that are customarily, as defined by local regulations, used on site-built homes, and is in compliance with the applicable standards of the United States department of housing and urban development at the time of its production.

Though not referred to specifically as a, modular home, state building code regulations consider modular homes to be „factory-built buildings that are regulated under ARM 80.70.500, et al. Unlike manufactured homes, they must conform to the requirements of the Uniform Building Code and be inspected at the factory where they are assembled. Each design must be reviewed by the Building Codes Bureau and each unit must carry a data plate that describes design loads and an insignia issued by the Bureau.     Manufactured housing is required by state codes to comply with a health and safety standard by satisfying the requirements of the national Manufactured Housing Construction and Safety Standards. When placed in areas that have zoning regulations, they are also required to satisfy an appearance standard by providing a pitched roof, a minimum size, and roofing and siding that is equivalent to what is required for site-built homes.

City Zoning Ordinances:


3.1 Helena. The City of Helena is in the process of revising their zoning regulations. Current zoning regulations do not define manufactured homes separately from mobile homes. As such, manufactured are restricted in R-1 and R-2 districts without a conditional use permit. The Helena ordinance does not conform to the language in the current state codes.

3.2 Billings. The Billings ordinance defines three classes of manufactured homes. All must meet the HUD standards, be composed of one or more components, each of which was substantially assembled in a manufacturing plant and designed to be transported to the home site on its own chassis, and exceeds 40 feet in length and 8 feet in width.

Manufactured home, Class A. A manufactured home constructed after July 1, 1976, that meets or exceeds the construction standards promulgated by the U.S. Department of Housing and Urban Development that were in effect at the time of construction and that satisfies each of the following additional criteria:a. The home has a length not exceeding four (4) times its width;b. The pitch of the homes roof has a minimum vertical rise of three (3) inches for each twelve (12) inches of horizontal run (3:12), and the roof is finished with a type of shingle that is commonly used in standard residential construction;c. The exterior siding consists of wood, hardboard, aluminum or vinyl siding comparable in composition, appearance, and durability to the exterior siding commonly used in standard residential construction;d. A continuous, permanent perimeter foundation, which complies with the Uniform Building Code, is installed under the home; ande. The tongue, axles, transporting lights, and removable towing apparatus are removed after placement on the lot and before occupancy. Manufactured home, Class B: A manufactured home constructed after July 1, 1976. That meets or exceeds the construction standards promulgated by the U. S. Department of Housing and Urban Development that were in effect at the time of construction but that does not satisfy the criteria necessary to qualify the house as a Class A Manufactured Home. Manufactured home, Class C: A manufactured home that does not meet the definitions criteria of a Class A or Class B manufactured home.The Billings ordinance also provides a definition for a modular home:

Modular home: a dwelling unit constructed in accordance with the standards set forth in the Uniform Building Code and bearing the insignia of the State of Montana, applicable to site-built homes, and composed of components substantially assembled in a manufacturing plant and transported to the building site for final assembly on a permanent foundation. Among other possibilities, a modular home may consist of two sections transported to the site in a manner similar to a manufactured home (except that the modular home meets the Uniform Building Code Standards applicable to site-built homes), or a series of panels or room sections transported on a truck and erected or joined together on the site.

The Billings codes limit placement of manufactured homes to a Residential Manufactured Home District within the city and to county districts.

3.3 Great Falls. The Great Falls ordinance permits manufactured houses in Suburban, B residential, Residential and O/R transition districts. Manufactured housing is defined as:

17.09.364 Manufactured house. Manufactured house means a factory assembled double wide or multi-section structure (excludes single-wide units with or without an expandable room) transportable in sections to a site for installation and use as a dwelling unit when connected to required utilities and designed as a module for combination with other elements to form a dwelling unit and which has been certified as having been constructed after June 15, 1976, in accordance with the construction standards of the U. S. Department of Housing and Urban Development and which also meets the appearance standards provided in Section 17.09.366.

17.09.366 Manufactured house appearance standards. A. The main body of the structure as defined in Section 17.09.364, must consist of two or more sections when assembled being basically rectangular in plan and having a minimum square footage of nine hundred fifty square feet.
B. The roof must have a minimum pitch of two and one-half to twelve covered with a nonmetallic wood shake, fiberglass or asphalt shingle.
C. The siding must be metal lap siding, or simulated wood siding, or wood or masonry veneer siding.
D. Attached to the roof of the house must be an eave (excluding rake) of at least twelve inches in width, which may include and be partially comprised of a maximum four-inch gutter.
E. The house shall be set on a foundation that is approved by the City Building Official. A complete perimeter enclosure is required that will match or coordinate with other conventional foundations in the neighborhood and conform to the Montana Energy Code.

Code Requirements:

Most cities have adopted the Uniform Building Code (UBC) of the International Conference of Building Code Officials (ICBO). All construction within these cities must satisfy the requirements of the UBC and are inspected for compliance by the local building inspector.

Manufactured housing is constructed to HUD requirements which, in turn, are required to meet the Manufactured Housing Construction and Safety Standards of the Congress of American Building Officials (CABO). Both codes address issues of public health and safety with regard to home construction. The primary difference between the two codes lies in the types of structures they encompass and referenced standards. The CABO code that applies to manufactured housing is limited only to single-family residential homes that are constructed in a factory setting. It includes requirements for building materials and assembly as well as plumbing, heating, and electrical installations.       The UBC is a broad range building construction code that includes all anticipated occupancies and, as such, is more voluminous than the CABO code. Plumbing, heating and ventilating are generally regulated under the Uniform Mechanical Code (UMC) and electrical work is regulated under the National Electric Code (NEC).

In local jurisdictions that adopted a building code enforcement program, each home constructed on-site and each modular home assembled on-site are subject to inspection for code compliance by the local Building Official. When a building code enforcement program has not been adopted, local inspection of home construction seldom occurs and is frequently limited to electrical and plumbing inspection. The CABO code requires each manufactured home to be inspected at the factory before it is shipped. Each home must bear a certification label attesting that it was inspected and found to comply with the requirements of the CABO code. This inspection will occur on all manufactured houses whether they are located in an area that has adopted a building code enforcement program or not.

Modular housing is required to follow a similar process in that certification in the form of an insignia and a data plate that defines the design loads be attached to each home before it is shipped. The State Building Codes Division monitors the enforcement of applicable codes as authorized and described in ARM 8.70.501-577.

Objectives of Zoning Ordinances:

Review of the various zoning ordinances reveal a wide disparity in the understanding of manufactured housing and the role it plays in the housing market. Few of the ordinances fully conform to the language of applicable Montana State Codes. To better understand the role of manufactured housing, the primary objectives of zoning should be re-visited, particularly those areas that involve (1) construction and safety, (2) appearance, and (3) property values.

The issue of construction and safety as applied to manufactured housing is resolved in the language of state law and case history. So long as the manufactured house meets the requirements of state law and each house is certified to comply with the standards of the national Manufactured Housing Construction and Safety Standards, the issue becomes moot. The HUD-referenced CABO standards are considered equivalent to any adopted building code. Local codes, such as the Uniform Building Code, may apply only to those additions to a manufactured home that are constructed on-site or without CABO certification such as foundations, porches, decks, and garages. Issues of appearance can be and are considered in a variety of ways. The Billings code defines issues of appearance in a Class A manufactured home but severely, by comparison, restricts placement of manufactured homes. The Great Falls code addresses appearance, but departs from the language of Title 70-2-203(6) by being both more and less lenient.

Appearance standards can be impacted positively or negatively regardless of the type of construction. They should be developed carefully and applied equally to all types of construction with the intent of establishing the aesthetic value of neighborhoods.
Property value issues are valid and are a necessary part of zoning regulations. There is, however, a need for caution in assuming that manufactured housing will negatively impact property values. Title 70-2-202(3) refers to a Rebuttal presumption that the placement of a manufactured home will not adversely affect property values of conventional housing. This would suggest that manufactured housing should not be assumed to reduce property value. Appraisal comparisons should be made to demonstrate whether property values will be affected or not.

Manufactured housing is directed toward the affordable housing market, a sector that comprises a significant number of home buyers in the State of Montana. Restricting the use of quality affordable housing without due consideration is a disservice to those that need access to this market. When there are valid reasons to restrict placement of manufactured housing, efforts should be made to provide opportunities for sitting these homes elsewhere. This can be achieved through the use of Manufactured Home Park districts and transitional zones between districts. Some areas may be expanded to allow manufactured homes that demonstrate their ability to match other types of permitted homes in appearance and value.

Appearance Comparisons:

Appearance issues are elusive and subjective. Frequently, the appearance of a home is determined by external influences such as landscaping, sidewalks and decks. It is common to see site-built homes constructed with identical dimensions and floor plans, differing only in color or orientation.

When compared side-by side, a distinction between types may be difficult to make.

The appearance of a manufactured home can be influenced by the detail surrounding the home itself. Note the influence that landscaping has on the overall appearance of this manufactured home.

Modular homes are very difficult to distinguish from manufactured homes. This modular home could easily be mistaken for either a site-built home or a manufactured home.

Site-built homes, in an effort to achieve comparable economy, are generally very conservative. This example of a site-built home could be mistaken for a manufactured home.

Value Considerations:

The value of any home relates to the quality of construction and the purchase price. It also relates to the long term cost for maintenance and operation and the resale value. From the Arkansas, Planning and Zoning Quarterly;

Manufactured homes are constructed with virtually the same materials used in site-built homes. In contrast, however, manufactured homes have the advantage of using engineered design applications and the most cost-effective assembly line techniques to produce a quality home at a much lower cost per square foot.

To ensure quality, the design and construction of the home are monitored by both HUD and its monitoring contractor, the National Conference of States on Building Codes and Standards (NCSBCS). The familiar red seal, or certification label attached to the exterior of a manufactured home indicates that it has passed the various stages of design review and monitoring.

Much of the concern relating to the value of manufactured homes evolves from the development of manufactured homes as trailer houses. The industry has advanced significantly by incorporating solid wood framing, comparable exterior siding and roofing, and the use of alcoves, roof overhangs, and architectural window treatment.

Suggested Zoning Language:

Zoning ordinances designed to restrict placement of manufactured housing should be considered only after fully evaluating the legal ramifications and the impact that such restrictions may have on the affordable housing market. Generally, zoning that specifically restricts manufactured housing and not other forms of housing should be avoided. Montana law has defined a minimum standard of size and appearance for manufactured

Title 76-2-203(6), MCA (municipal and county zoning statutes) … „manufactured housing. means a single-family dwelling, built offsite at a factory on or after January 1, 1990, that is placed on a permanent foundation, is at least 1,000 square feet in size, has a pitched roof and siding and roofing materials that are customarily, as defined by local regulations, used on site-built homes, and is in compliance with the applicable standards of the United States department of housing and urban development at the time of its production.

This standard effectively assures that manufactured housing will be comparable or better than conventional housing that would be permitted in similar circumstances, particularly for housing that
is directed toward the affordable housing market.

Manufactured housing can compete at mid- and high-end markets, as well. Because a home is fabricated under controlled and monitored conditions should not be a reason to deny its availability to any market. The test should be one of construction quality and comparable appearance. If a factory built home can compare to conventional housing, the market should not be denied the value and cost saving inherent in controlled construction. It is that standard of quality and appearance that should appear in zoning regulations without any intention of denying one particular method of construction.