This page is dedicated to the discussion of Accessory Dwelling Units in Missoula.

The Missoula City Council is currently considering an amendment to the text of our zoning code to allow ADU's as an accessory use in all zones. They are currently allowed in the "multi-family" zones but prohibited in the "single-family" zones. I put that in quotes because that term is something of a misnomer even though it is the common term. In Missoula, and Montana for that matter, law prohibits defining a family in the traditional sense. So it just means a household of people who live together. That "family" could be a group of blood and marriage related people or it could be a "family" of college age friends.

The arguments for encouraging ADU's generally fall into the following categories:

  • Provide affordable housing
    An ADU is generally a small unit that rents for less money. The associated rental income also makes the primary home more affordable for the home owner.
  • Increase home ownership
    When associated rental income is factored into the financing, the primary unit is more affordable, bringing ownership into reach of more people.
  • Help the elderly stay in their homes longer
    As the elderly find their space needs reduced and their incomes fixed, renting out space can help them stay in their homes.
  • Increase diversity in neighborhood
    As real estate in our core neighborhoods becomes more expensive, it becomes harder and harder for young families to buy into the neighborhood. The trend is to split the neighborhood between people in their 50's and 60's who purchased into the market 15 or more years ago, and investors that rent out to the homes to the maximum number of young occupants. ADU's will provide options for families of moderate income to buy into the neighborhoods and the small rentals appeal to people of all demographics looking for smaller living space.
  • Encourage resource efficiency and "green" homes
    Building small homes close to the core is more efficient in terms of city infrastructure and transportation requirements. 
  • Respect private property rights
    At least in the context of an internal ADU like and attic or a basement, people should be able to rent out part of their home if they want to.
  • Maintain neighborhood character
    The increasing price of housing in our core neighborhoods creates a significant threat to the character of these neighborhoods. As young families become priced out of the neighborhoods, all we have left are the wealthy, the elderly, or those willing to live in group housing situations. We lose diversity and we lose children, which leads to the closing of our neighborhood schools which serve as the anchors of neighborhood cohesion. This interpretation considers the people who live in a neighborhood to be an important element of that neighborhood's character.
  • Decrease overcrowding
    Under our current laws there is nothing stopping a person from buying a home in one of these "single family" neighborhoods and renting that home to 11 college students. In fact, in the neighborhoods close to the campus, this is clearly the highest and best use of these structures and just about the only way to justify the price that they sell for. Since the ADU proposal requires owner occupancy, this creates an opportunity for a traditional family to buy one of these homes and rent a small unit to one or two people to help pay for it. This should reduce the incidence of overcrowding and create an alternative to the economics that encourages it.

The arguments against ADU's appear to fall into these categories:

  • They change the neighborhood character
    In this case, folks define neighborhood character as the physical form of the buildings and percent of lot coverage commonly found in the neighborhood. If we allow accessory structures this will change the pattern of land use and therefor the character of the neighborhood.
  • Will bring overcrowding
    The extra unit means more people.