Montana Tiny House Builders

In the section 24.301.154 of the State’s official building code, the department vows to officially recognize and regulate tiny houses as their own category of dwelling, effective in all areas of the state beginning on December 7, 2019, and onward. This is great news for those who are looking to live tiny in the state of Montana.

Are Tiny Houses On Foundation Legal In Montana?

The official building code for the state of Montana explains that the state defers to the Appendix Q in the 2018 International Residential Code, while adding a few of its own amendments to the code. These amendments are listed below and can also be read in the Administrative Rules of Montana.

Appendix Q is the tiny-house friendly Appendix in the IRC. It legalizes lofts, lowers the minimum ceiling height for traditional dwellings, creates egress requirements specifically for lofts, and allows the building of stairs and ladders in small spaces. It applies to tiny houses used as single-dwelling units.

Here are some of the regulations worth noting from Appendix Q:

• Habitable space and hallways in tiny houses shall have a ceiling height of not less than 6 feet, 8 inches.
• Bathrooms, toilet rooms, and kitchens shall have a ceiling height of not less than 6 feet 4 inches.
  Obstructions such as beams, girders, ducts, and lighting shall not extend below the minimum ceiling heights.
• Lofts may have ceiling heights less than 6 feet, 8 inches.
• Lofts shall have a floor area of not less than 35 sq. ft. and shall not be less than 5 ft. in any horizontal dimension.
• The loft guards shall be located along the open side of the lofts.
• Loft guards shall not be less than 36 inches in height or one-half of the clear height to the ceiling, whichever is less.
• Tiny houses shall meet the requirements of Section R310 in the One-and-Two-Family Dwelling Building Code for Emergency Escape and Rescue Openings (Read the PDF here).
• In sleeping lofts, egress roof access windows shall be deemed to meet the requirements of Section R310. (Read the PDF here)
• Windows shall be installed such that the bottom of the opening is not more than 44 inches above the loft floor, provided the egress roof access window complies with the minimum opening area requirements of Section R310.2.1. (Read the PDF here)

In Montana, Appendix Q applies to any city, county, or town building code jurisdiction. In addition to the regulations from the IRC, Montana’s secretary of state has amended certain sections of the code to apply specifically to Montana.

Here of the parts of Appendix Q that have been changed in the state of Montana:

• Chapters 11 through 14 of Appendix Q have been deleted.
• Subsection R102.7 has been deleted and replaced with “The legal occupancy of any structure existing on the date of this code shall be permitted to continue without change, except as is specifically covered in this code or the legally adopted fire code as administered by the fire authority having jurisdiction.”
• Subsection R301.6 is deleted and replaced with the following “Snow loads shall be determined by the building official. In areas of the state outside of certified city, county, or town jurisdictions, the design snow load shall be based on the ground snow loads.”
• In Subsection 302.2.2 delete “Chapters 34 through 43” and replace with “the adopted electrical code in ARM Title 24, chapter 301, subchapter 4.”
• In Subsection 302.2.4 delete exception number five and replace with the following “Townhouses separated by a common two-hour fire-resistance-rated wall as provided in Section R302.2.”
• Subsection R302.13 is deleted.
• Subsection 309.5 is deleted.
• Subsection R311.7.5.1 is amended to allow a maximum riser height of 8 1/4 inches.
• Subsection R311.7.5.2 is amended to allow a minimum tread depth of nine inches.
• In Subsection 312.1.1, delete the first sentence and replace with the following: “Guards shall be located along open-sided walking surfaces, including stairs, ramps, and landings, that are located more than 30 inches measured vertically to the floor or grade below.”
• Section R313 is deleted in its entirety.
• In Subsection R403.1.1, add the following: “Exception: The building official may allow footings to be designed in accordance with Section R403 of the 2012 IRC or may allow footings engineered by a design professional.”
• Subsection 403.1.6 is deleted.

If these regulations are followed, your tiny house on foundation should be legal in the state of Montana. However, if you’re unsure, you can always call the department in your local municipality that deals with building laws and ask them for clarity.

Are Tiny Houses On Wheels Legal In Montana?

Not only is the State of Montana at the top of their game when it comes to tiny houses on foundation, they also officially recognize tiny houses on wheels as their own independent dwelling category, sperate from recreational vehicles or traditional dwellings.

If you don’t know, it’s extremely common for tiny homes on wheels to kind of get lost in the shuffle when it comes to building laws. Some states categorize them as recreational vehicles, some as mobile homes, and others don’t have a solid category for them at all. Montana is leading the charge.

The State of Montana classifies tiny houses on wheels in House Bill No. 494 (Read the PDF Here), created in 2019 through the Montana legislature. Essentially, this bill revises statewide travel trailer laws to explicitly all the development of tiny homes on wheels.

Section 15-24-201 of the bill defines a tiny home on wheels as a home exceeding 8 feet in width or 45 feet in length designed to be moved from one place to another by an independent power connected to the tiny house, or a tiny house up to 8 feet in width or 45 feet in length, or tiny home on wheels that is used as a principal residence.

While Montana does have its own section for tiny houses on wheels, they still belong under the larger umbrella of travel trailer laws. This means tiny houses on wheels will still need to comply with all relevant regulations and restrictions on an RV.

Tiny House Building Codes In Key Counties Of Montana

Some counties are more friendly to tiny homeowners while others prohibit the lifestyle. County building laws have a lot of power in the state of Montana when it comes to what is and is not allowed.

Missoula County, Montana

Missoula County, Montana, is welcoming of tiny house enthusiasts. They were one of the first counties to vote yes on the introduction of Appendix Q.

Tiny House Building Codes In Key Cities Of Montana

Some cities are especially accommodating of the tiny house lifestyle. Other cities, particularly the more urban ones, tend to make it harder to live tiny.

Missoula, Montana

Missoula, Montana, is highly in favor of tiny housers. The city allows tiny houses and defines them as any residential structure on a permanent foundation with a surface area of 320 square feet or less.

Bozeman City, Montana

Bozeman City, Montana, is also accommodating to the tiny house lifestyle. The city has even welcomed a tiny house village, Housing First Village, which actively works to prevent homelessness through the provisions of tiny homes.