Architecture, Ask a Designer, Multifamily Residential
The Middle Housing Bill FAQ
Washington State’s HB1110 — also called the Middle Housing Bill — is setting the stage for big changes to code and zoning in Seattle. But what is middle housing? And what is the “missing middle” HB1110 seeks to fill? You have questions and we have answers based on our best, current understanding of this landmark legislation.
September 26, 2024
The implementation of Washington State’s Middle Housing Bill HB1110 is still developing. For the most up-to-date information, contact your local jurisdiction or designer to learn how HB1110 directly impacts your property or your project.
The State of Washington passed HB1110 back in 2023. This bill, also known as the Middle Housing Bill, defines middle housing as, “buildings that are compatible in scale, form, and character with single-family houses and contain two or more attached, stacked, or clustered homes including duplexes, triplexes, fourplexes, fiveplexes, sixplexes, townhouses, stacked flats, courtyard apartments, and cottage housing.”
A year on, the impacts of HB1110 are still playing out as cities, counties, and the state figure out what the new legislation means for upcoming ordinance adoptions and building code impacts.
So, what kinds of impacts will HB1110 have? Who will it affect? And, if you are affected, what will it mean for you if you plan to update your property? Here, we break down frequently asked questions about HB1110 to help you understand what it all means.
What is HB1110?
HB1110 was a house bill adopted by the state legislature that requires cities in the State of Washington, including Seattle, to allow more types of housing options in areas that have typically been reserved for single-family homes and detached structures.
This is designed to allow for more housing density within these single-family areas, accommodating housing needs for growing cities, like ours. The bill specifically looks to increase the availability of what is sometimes called “middle housing.”
What is middle housing?
Middle housing includes housing types that bridge the gap between single-family homes, which may accommodate one household, and multifamily developments, which might accommodate hundreds of households.
Cities like Seattle are sometimes said to have a “missing middle” because they have few of these smaller scale housing types. The prescriptive list of housing mentioned above is what HB1110 defines as meeting these in-between housing types that aren’t quite multifamily or quite single-family.
Will this change the character of our neighborhoods?
This is a complicated question with a complicated answer. Predominantly single-family neighborhoods will likely see more density, sometimes with new construction. This, by nature, will change how our neighborhoods look and feel.
Is that bad? We don’t think so. Middle housing is something our community needs. It’s a positive thing for our communities to have greater access to housing – especially family-sized housing options that middle housing can provide. With the right owner, developer, and designer, middle housing will find a way to fit into the existing fabric of our neighborhoods in ways that feel intentional and beautiful, and enliven our communities.
How do I know if my property is impacted?
In Seattle, if your property is in a residential zone, it will likely be impacted by HB1110. You can explore current zoning in Seattle using the City’s interactive GIS map.
Qualifying cities and counties are organized into three tiers based on their populations and interconnecting growth areas with the largest city in the county. The Middle Housing Law also provides flexibility in implementation timelines that work with a city’s unique barriers while aligning with the state’s Growth Management Act objectives.
Seattle, for example, is required to adopt the new zoning compliance by June 30, 2025, as part of the One Seattle Plan to outline the changes unique to the city.
If my property is eligible for middle housing development, how many units can I add?
To know exactly what is possible for your particular property, you’ll need to speak with an architect who can assist with a capacity and feasibility study to explore strategies and opportunities for the development of your property.
In general, the three tiers of cities and counties can be a starting place to see how many units you may be able to add.
- Tier 1 Cities with a population larger than 75,000 are allowed up to 6 dwelling units.
- Tier 2 Cities with a population between 25,000 - 75,000 are allowed up to 4 dwelling units.
- Tier 3 Cities with a population less than 25,000, located in a county with a population of more than 275,000, and in a contiguous urban growth area with the largest city in the county.
Be sure to check with your municipality directly or hire an architect to confirm. In Seattle, a Tier 1 City, the number of units you might be able to add to will depend on where your property is located. Things like whether your property is located within a quarter mile from a transit stop, or whether you’re proposing the inclusion of affordable units will impact how many units your property might be able to have.
How much parking would I need to provide?
Parking requirements for your property may vary once local land use and zoning codes are adopted. For now, there are a few rules that could be applicable to your lot.
- If you’re within one-half mile walking distance of a major transit stop, then no parking is required.
- If your lot is currently smaller than 6,000 square feet, then one off-street parking space is required per unit.
- If your lot is currently greater than 6,000 square feet, then two off-street parking spaces are required per unit.
Does a detached ADU count as a unit?
Yes, a detached ADU, or DADU, would count as a unit. A related bill, HB 1337, which also passed in 2023, requires all cities and counties, regardless of population, to legalize up to two ADUs on any lot. Since this law has overlapping features to the Middle Housing Law, its best to check with your local planning department to get more information about what might be possible for your specific property.
My home is in an impacted area. Will I be required to update my property?
No. Just because your property is rezoned doesn’t mean you will be required to add more units. But it does open opportunities for you, or future owners who do wish to explore options, for adding units that could be beneficial for multi-generational households or to add an income stream.
How is Seattle’s Mandatory Housing Affordability (MHA) different than HB1110?
Seattle’s Mandatory Housing Affordability Program, or MHA, is a developer contribution program. In land use zones that have an M, M1, or M2 suffix, developers are required to either pay a fee per square foot of new residential or commercial development or incorporate affordable units into their proposed project.
Seattle is actively amending their land use codes in accordance with this statute. You’ll get the most up to date information by contacting your city’s planning office.
When does the Middle Housing Law take affect?
A draft Model Ordinance and User Guide with public participation and comment period has recently concluded. We are keeping a close eye on an updated state-wide Model Ordinance and User Guide set to be published in September 2024 as a preview of what’s to come. With the proposed local rules in progress, check with your local planning department to get more information about how this will impact your property or project.
What tools or resources are available to me if I’m interested in developing middle housing on my property?
If you’re interested in developing your property to take advantage of this new law, there are several resources available to help you decide whether it is feasible to do so. Cities and counties throughout Washington are actively amending their land use codes in accordance with this statute. Accordingly, it is strongly advised to contact your city’s planning office for further information.
Architects & Designers
Local architects who have experience with multifamily, single-family, and other residential housing types can help determine the feasibility for middle housing on your property while adhering to local regulations. If you would like to learn more about how this legislation will impact your property, please reach out to us discuss your project goals.
State Resources
The Washington State Department of Commerce is providing guidance, technical support on middle housing adoption for local governments across the state. Their page includes presentations and tools to learn more about envisioning middle housing on your property.
Real Estate Agents
A real estate agent familiar with your area can provide insights into the demand for middle housing in your area and understand potential rental income or resale value.
Financing Options
Explore financing options for your project, such as construction loans, renovation loans, or home equity lines of credit. Some lenders offer specific products for property development.
Legal Advice
Consult with a real estate attorney to ensure you understand all legal aspects of developing middle housing on your property. This includes permits, contracts with builders, zoning variances, and tenant agreements.
If you’re curious to know more about adding middle housing to your property, we’d love to chat. Reach out to us and let us know about your project!
Notes & Credits
Research and copywriting in collaboration with the B&V Team.
