If you’ve heard that Washington townhouses will no longer have “Unit A” or “Unit B” in their addresses, there’s an important distinction to understand.
Washington has changed its rules around unit lot subdivisions, which can allow homes within a development to be sold on separately owned lots. But the legislation does not establish a statewide ban on unit letters or automatically change existing townhouse addresses.
For buyers in Lake Stevens and Snohomish County, the useful question is: What exactly will you own, and what responsibilities come with it?
What Is a Unit Lot Subdivision?
Think of a larger property being divided into smaller lots associated with individual homes.
Washington’s Department of Commerce explains that these “unit lots” are individual legal lots that can be sold separately and have their own tax or parcel identification numbers.
Certain development standards are evaluated across the original larger property, called the parent lot, rather than requiring every smaller lot to meet those standards independently.
That flexibility can support housing such as townhomes on smaller lots.
A parcel number, however, is not the same thing as a street address. Having an individually owned lot does not, by itself, tell you how the home will be addressed.
What Changed Under SB 5559?
Engrossed Senate Bill 5559 took effect July 27, 2025. It establishes additional requirements for unit lot subdivision procedures in cities and towns fully planning under Washington’s Growth Management Act.
Among other changes, it calls for clear, objective development regulations and better coordination between subdivision review and the underlying housing project. It also requires recorded plat notes explaining important limitations affecting the individual lots.
Implementation is phased. Cities with comprehensive plan updates due in 2027 generally adopt the procedures with those updates; other covered cities generally have two years from the law’s effective date.
This is not an automatic approval for every property. Health, safety, environmental, and other applicable development requirements still matter.
Will “Unit A” and “Unit B” Disappear?
SB 5559 does not require every townhouse to lose its unit letter.
The change concerns land division and ownership. It does not automatically rename existing homes, convert existing condominiums, or establish one address format for all townhouses.
If a particular development advertises separate street addresses, verify its approved addresses and recorded ownership documents.
The address alone should never be your proof of what you are buying.
Does a Separately Owned Lot Mean No HOA?
No. Separate lot ownership can still come with shared property and responsibilities.
Washington’s subdivision framework contemplates remaining common portions of a parent lot being owned collectively by the individual lot owners or by their homeowners association.
For buyers, that makes the documents worth reading carefully.
Questions to Ask Before Purchasing
- Who maintains shared driveways, landscaping, and drainage?
- Who pays for roof, siding, or shared structural repairs?
- What insurance must each owner carry?
- Are there dues, shared maintenance agreements, or anticipated expenses?
- What do recorded easements and plat notes allow or restrict?
A low monthly payment to an association is only one part of the ownership picture.
What Does This Mean in Snohomish County?
Unit lot subdivisions are not entirely new here. Snohomish County has previously used them to create individual townhouse lots.
The newer state legislation builds on that broader approach. The applicable process still depends on the property’s jurisdiction, approved development, and recorded documents.
A Lake Stevens mailing address is a starting point. Confirm which city or county department actually governs the property.
My Advice for Townhouse Buyers
As a Lake Stevens native and real estate broker, I want buyers to understand the home beyond its layout and listing photos.
Before you make an offer, establish what land you own, what you share, and how future expenses will be handled. Have your lender and insurance provider review the actual ownership structure early, too.
If you’re comparing townhomes in Lake Stevens or Snohomish County, reach out through TaylorStefani.com. I can help you identify the documents and questions that matter before you commit.
Sources and References
- Washington Legislature – ESB 5559 Final Bill Report
- Washington Department of Commerce – Planning for Middle Housing
- Snohomish County – Updating Urban Residential Development Regulations
Disclaimer: This article provides general information. Property-specific legal questions should be reviewed with a Washington real estate attorney.
