Background:

A zero lot line subdivision is a way to create zero lot line homes, a type of single-family home that is attached to another, sharing a common wall. Zero lot line homes can take various forms, such as a townhouse, attached cottages or duplex/fourplex. But unlike condominiums, the homeowner has separate ownership of the unit, the ground beneath, and often ownership of a private front and back yard.

Zero lot line homes are created by subdividing the land into small “unit lots” about the size of the unit. This special subdivision process creates single-family attached housing units that are sold fee-simple (meaning the structure and land underneath are both owned by the homeowner, just like a detached single-family home). These subdivisions typically have shared access driveways, smaller and narrower lot sizes, and reduced setbacks.

The zero lot line subdivision process creates more affordable owner-occupied units. The zero lot line homes offer a better variety of single-family housing options, a downsize option for seniors, and an affordable entry into ownership for first-time home buyers. The subdivision process is like a regular subdivision, and is much simpler to finance, construct and regulate than condominiums.

What’s proposed: Code changes to expand options

Zero lot line homes are already allowed in Sumner. But the process to create them is cumbersome. Creating a streamlined zero lot line subdivision process is a City Council priority for addressing housing needs. The City is looking at ways to encourage unit zero lot line homes in more areas around town. Strategies and concepts being explored include:

• Improve the permit process to make the zero lot line subdivision process simpler.
• Reduce minimum lot widths to allow a lot to be as narrow as a unit.
• Reduce side setbacks to allow for shared walls.
• Increase lot coverage allowance.
• Require yards & landscaping to ensure privately owned open space.
• Update rules for private driveways to allow narrow access drives to serve clusters of homes.

Add flexibility to the process and standards to create more design options.

September-October 2022 Update

July-August 2022 Update

Example of private drive and zero lot line lots fit into odd-shaped site: