All About Thrive: Part 4 - Missing Middle Housing
Image from the Sightline Institute
“Missing middle housing.” “Attainable housing.” “Multiplexes.”
What does it all mean?
In short, we’re talking about different types of buildings. A building in most neighborhoods is only allowed to house one family — this is a single family home. There are other types of buildings people live in, such as townhomes, duplexes, triplexes, quadplexes, and small multifamily buildings that contain between 5 to 12 homes. These are typically the housing types people mean when they talk about “missing middle housing.”
These housing types are missing, because they’re not allowed to be built in most neighborhoods in the United States. And they are "middle" because they exist in the middle of the spectrum between very low density housing (single family detached homes) to very high density homes (mid- and high-rise apartment buildings).
Image from Montgomery Planning
You can find examples of neighborhoods with a mix of housing types in places around the region that many of us know and love: East Silver Spring, College Park, Kentlands, Alexandria, the City of Frederick, Takoma Park. Homes in “missing middle” buildings are typically less expensive due to their smaller square footage and/or splitting the cost of land between multiple homes. Throughout American history, these types of homes provided a pathway to homeownership for many people who otherwise wouldn’t have been able to afford a single family home.
This changed during rapid suburbanization in the 1960s. Local governments zoned most of their land to only allow single family detached homes. Today, the vast majority of residential land in Montgomery County only allows single family detached homes and single family homes make up two-thirds of the county’s housing stock.
What does Thrive say about single family homes and other housing types?
Below are some direct quotes from the plan’s general text regarding single family zoning and duplexes, but you can read the plan for yourself to learn more about what it says (and doesn’t say) on this topic and others.
“The preservation and protection of neighborhoods dedicated exclusively to detached single-family houses has left residents disconnected from retail and other services, encouraged the construction of stand-alone public facilities, and perpetuated the inefficient use of land.”
“For empty nesters who want to downsize but cannot find a smaller, less expensive home in the neighborhood where they raised their family, a small apartment building or a courtyard bungalow could provide a welcome alternative to relocating from the area.”
“We need less expensive alternatives to single-family detached dwellings because a wider variety of options accessible across the spectrum of incomes, family sizes, and lifestyles will make the housing market function effectively for all of our residents at every stage of their lives.”
These are the two mentions of duplexes in the plan’s goals and policies:
“Examine options for allowing a wider variety of housing types such as tiny houses, cottages, courtyard clusters, duplexes, multiplexes, small apartment buildings; shared housing, cohousing and accessory dwelling units (ADUs).”
“Support creative housing options including personal living quarters and/or micro units; “missing middle” housing types such as tiny houses, cottages, duplexes, multiplexes, and small apartment buildings; shared housing, cooperative housing, co-housing, and accessory dwelling units (ADUs), to help meet housing needs and diversify housing options.”
A small apartment building and duplex in Seattle. Image from the Sightline Institute.
What does this mean for me and my neighborhood?
Thrive does not change zoning — it is a framework to guide future plans and policies. Any actual zoning changes to allow townhomes, duplexes, or other housing types would have to happen through subsequent master plans or zoning amendments with a public process. No one is going to tear down your house. (This is something we’ve heard a lot of people are concerned about! There is no risk of this happening, unless you choose to sell your house.)
Housing types like duplexes are most likely to be built in places already experiencing a high amount of existing single-family homes being torn down to build a new and larger single-family home. Areas where teardowns are primarily occur are mainly inside the Beltway surrounding Bethesda and Silver Spring.
However, even in the neighborhood where teardowns are the most prevalent (pictured below), if 30% of those teardowns were rebuilt as duplexes or triplexes, that would only affect six properties over 20 years. This moderate level of new helps add housing options and choices in neighborhoods but does not significantly change the overall character.
Sample neighborhood with active tear-down custom home market, from Montgomery Planning. Dots represent single family home rebuilds and stars represent multi-unit construction.
Multiplexes aren’t a silver bullet
Allowing different types of small multifamily buildings like duplexes will not provide enough housing to meet demand, nor will it fully address the county’s housing affordability needs. They are one tool in the toolbox, but we’ll need every strategy in order to ensure everyone has a home they can afford and that meets their needs. Thrive discusses these others strategies, too.