Second in a two-part series

In addition to letting modern-day developers skirt the Growth Management Act and other laws, Washington’s provisions for vesting development rights over years and even decades pose a potentially ruinous development problem: thousands of building lots established before the growth law was passed in 1990.

For those lots, the vested building rights never expire. The same goes for small subdivisions — up to nine homes in areas designated for urban growth, and four houses otherwise.

Add courts' reading of the U.S. Constitution as prohibiting government from taking private property without just compensation, and you have a recipe, growth planners fear, for suburban sprawl that overtaxes roads and water supplies and other services in what are supposed to be rural areas.

Vesting protects thousands of building lots subdivided decades ago, many far too small to support a house under current codes. Statewide, there could be tens of thousands. But no one knows how many there are, or where. Generally, county governments allow a single house to be built on any lot, no matter how small. (The exception comes when it would be unhealthy, such as a lot so small that drinking water would have to be drawn from near a septic tank. Some builders, though, try to find ways to use even these tiny lots. One in Kitsap County proposed to serve 78 homes on 12 acres with a small sewage treatment plant.)

In 2008 alone in just two counties — Pierce and Snohomish — building permits for more than 800 homes were issued for old lots established before the state Growth Management Act took effect, research by the Puget Sound Regional Council indicates. The vast majority of homes constructed recently in the rural stretches of Kitsap, Pierce, and Snohomish counties were built on lots where modern-day development rules don’t all apply, according to research council, a government growth-planning agency.

Tracking of building permits suggests that development is occurring in those counties’ rural areas at rates far higher than what the counties set as their growth targets under the Growth Management Act.

Kitsap appears to be the most problematic, with one-third of the homes approved in 2008 outside areas designated for urban development. And 2008 actually represented an improvement; half the new homes approved in Kitsap in the decade before that were outside the urban areas.

In Snohomish in 2008, one in seven new homes went outside the urban-growth area, and in Pierce the figure was one in four. Less than 4 percent of King County’s growth occurred outside its urban growth boundaries in 2008. (King County’s efforts to shape growth started significantly earlier than other counties’ and King has worked hard in recent years to limit rural building that will harm the environment.)

The building adds up fast. From 1998 to 2008, more than 40,000 homes were built outside areas designated for urban growth in King, Pierce, Snohomish and Kitsap counties, the council’s tracking of building permits indicates.

Although some of those rural homes were envisioned under county plans developed under the Growth Management Act, not all of them were. And vesting remains a significant challenge to making Washington’s growth-management law work in rural areas, according to Carol Naito, principal planner and demographer with the regional council.

Her colleague, council staffer Ivan Miller, said counties need to get a handle on how many of these old lots are out there, because they could significantly hamper efforts to prevent suburban sprawl that threatens to choke the rural areas.

Miller asks: “What’s in the pipeline? What’s been added to the pipeline?”

No one knows.

The first part of the series is here. InvestigateWest is a nonprofit investigative journalism center based in Seattle. For information on how you can support independent investigative reporting for the common good, go to invw.org.