Want a snapshot of the region’s changing shape? Look at 2026.

Seattle, once our undisputed growth engine, posted a meager 0.8% population increase last year, according to the state Office of Financial Management. Bellevue was even more sluggish: 0.2%. Meanwhile, the fastest-growing sites in the region were places many Seattleites couldn’t find on a map — Stanwood and Carnation, both topping 4% growth in a single year.

It’s a broad national trend that’s been dubbed the “Donut Effect”: remote work pulling growth away from city centers and close-in suburbs and dumping it on the exurbs.

The state’s data support this. Since 2020, Black Diamond, nestled in the foothills of the Cascade Mountains in Southeast King County, has been the fastest-growing city in the Seattle area. Its population is up 61% — a gain of more than 2,800 residents. The rest of the Top 5 are in Snohomish County. Sultan is up 45%, adding more than 2,300 people. Stanwood grew 21%, Lake Stevens 20%, and Arlington 18%. Some growth in these Snohomish County communities came from annexation, in addition to new development.

Compare that to the 2010s. Over that entire decade, Black Diamond grew just 13%. Sultan and Arlington grew 11% each. Stanwood and Lake Stevens grew faster — 24% and 27% — but that was over 10 years, not six. These towns are nearly matching or beating their whole previous decade’s growth in about half the time.

It’s not that these places are cheap. Plenty of buyers are paying a premium for homes in Black Diamond or Lake Stevens. What they’re buying is a different kind of lifestyle than they might have gotten in Seattle: small-town feel, mountains and water at your doorstep, a newer house with a yard instead of a town home stacked three stories on a postage-stamp lot.

Remote work is the obvious driver. I wrote recently about the fall in Seattle-bound commuting since 2020, as working from home went from a rare perk to a routine arrangement. The exurban data tells the same story from the other end: in Black Diamond, for example, 25% of employed residents now work from home, according to the latest census figures. Before the pandemic, it was 8%.

And that likely understates things. The census question only asks how someone commuted most days the previous week — so a person working from home two days and driving in three doesn’t count as remote in the data. But two remote days a week can be enough to change where someone decides to live.

For tech workers and other deskbound professionals chasing square footage, trading a daily commute for an occasional one is easy.

Growth like this doesn’t come free, though. Seattle learned that in the 2010s. Now it’s the exurbs’ turn.

Take Black Diamond, a former coal town filling in fast with master-planned subdivisions. That development was approved and in motion well before the pandemic — but remote work has supercharged it, delivering a wave of buyers suddenly fine with living around 30 miles from downtown. Two-lane roads built for a fraction of the traffic are far more congested, and schools are strained.

Black Diamond Mayor John Adler says the city has adapted remarkably well, but acknowledges the growing pains. “Adding thousands of residents in a relatively short period of time has put additional pressure on transportation, infrastructure and city services,” he said in an email, “and there have certainly been differing opinions in the community about the pace and impacts of that growth.”

In Black Diamond and other fast-growing exurban towns that used to measure growth in decades, the pace of change has become the lead story.

Moving forward, Adler says the city’s challenge is finding balance — keeping infrastructure and services on pace with growth while diversifying revenue streams for long-term financial stability.