In neighborhoods across Mercer Island, Bellevue, Kirkland, and Snohomish, a quiet but powerful shift is underway. Backyards, driveways, and empty side lots may soon take on new life, thanks to House Bill 1110 (HB 1110)—a bold new law reshaping residential zoning across Washington State.
Passed in 2023 and now taking effect, HB 1110 requires many cities to update zoning codes to allow two to six housing units on parcels previously limited to a single home. That means duplexes, triplexes, fourplexes, and cottage-style clusters could soon sit side by side with traditional houses.
The question isn’t whether change is coming. It’s: How ready are we to shape it?
A Law Born of Urgency
Washington’s housing shortage didn’t happen overnight. For years, demand has outpaced supply, pushing home prices beyond reach for many families. Zoning restrictions that limit development to one home per lot—particularly in job-rich cities like Bellevue and Kirkland—have made it difficult to accommodate growth.
“Three-quarters of Seattle’s land is still zoned single-family,” says Dean Jones, President and CEO of Realogics Sotheby’s International Realty (RSIR). “That model worked in the 20th century—but not for the realities of today. HB 1110 is potentially offering more attainable ways to live where you work.”
And this is not optional. For cities with populations over 25,000—including all four featured in this magazine—HB 1110 is a mandate.
So, What Will It Look Like?
Picture this:
• A homeowner builds a backyard cottage for a parent or tenant.
• A single-level home is thoughtfully redeveloped into a triplex.
• A corner lot transforms into a small cluster of homes, designed to complement the neighborhood.
This is called “missing middle housing”—a style of gentle density that fills the gap between single-family homes and large apartment buildings. And it’s exactly what HB 1110 encourages.
According to real estate economist, Matthew Gardner, , “The lack of attainable housing is not just a supply issue—it’s a zoning issue. Missing middle housing helps solve both by increasing inventory without changing the character of our communities overnight.”
Innovation at the Forefront
Still, navigating these changes isn’t easy. That’s where technology and expertise come in—and why RSIR has become a recognized leader in this space.
Dean Jones and his team aren’t just interpreting the law—they’re building the future. RSIR is piloting AI-powered tools that analyze zoning, land potential, and market value—helping brokers and property owners understand what’s possible.
At the center of this innovation is Tadashi Shiga, Co-Founder of Realtie, an AI platform built to streamline infill development. Realtie lets users visualize development potential, model financial returns, and identify risks—all before the first permit is filed.
“Most homeowners don’t realize they’re sitting on untapped potential,” Shiga says. “With the right insights, a single lot can become a retirement plan, an income source, or a multigenerational solution.”
He and Jones are working closely to train brokers, educate communities, and connect residents with a full-service ecosystem—from planning to permitting to resale.
Who Can Benefit?
This new framework opens doors for:
• First-time buyers priced out of traditional homes
• Multigenerational families wanting to stay close
• Empty nesters seeking to downsize or generate rental income
• Longtime residents who may want to develop or sell strategically
Gardner emphasizes, “The shift isn’t just about affordability. It’s about retaining community. These homes allow the people who serve, teach, and support our cities to live here too.”
For sellers, these changes can dramatically increase the value of their land. For buyers, they open up new paths to homeownership. For neighborhoods, they bring fresh energy—while preserving the spirit of place.
What Are the Concerns?
Naturally, some residents worry about traffic, parking, and infrastructure. Others fear rapid development or disruption of neighborhood character. These are real concerns—and cities are taking them seriously with implementation timelines, design standards, and public input.
Gardner asks,
“How can we encourage companies to move to the Pacific Northwest if housing prices are so high that they simply cant afford to pay employees enough for them to be able to own a home?”
What You Can Do Now
✅ Explore your city’s plans – Each municipality is rolling out its own approach. Visit planning websites, attend open houses, and stay informed.
✅ Talk to a professional – From architects to lenders, planners to Realtors, the right team can help you understand your property’s true potential.
✅ Start the conversation – With neighbors, with family, with city leaders. This is a shared journey, and your voice matters.
Final Thoughts
This isn’t about density for density’s sake. It’s about building a future where our children can afford to live nearby. Where aging parents can move into a backyard cottage. Where creative solutions meet real needs.
As Gardner puts it: “The neighborhoods we build today will shape the lives of the next generation.”
House Bill 1110 invites us to rethink the boundaries—of our lots, our zoning, and our assumptions.
It’s about rewriting the neighborhood, yes.
But more than that—it’s about reimagining what community can be.
“The lack of attainable housing is not just a supply issue—it’s a zoning issue." Matthew Gardner