The recently ended session of the Oregon Legislature is best known for the climate bill that got away. Republican senators fled the state to block a plan to cap and trade carbon emissions, and Democrats abandoned the idea.

But after persuading the GOP to eventually return, Democrats did pass a different piece of environmental legislation last month with Republican help.
House Bill 2001 makes Oregon the first state to end single-family zoning in cities larger than 10,000 people. While it is thought of as a housing bill, it also could have major carbon benefits. The bill could increase the density of Oregon's cities—which in turn could decrease carbon emissions.

"It's an important piece of the puzzle," says Steve Novick, who championed dense housing while on the Portland City Council. "A huge percentage of carbon emissions comes from cars, and from heating and cooling houses.

"We know that when enough people live within walking distance of each other, a grocery store will spring up that they can all walk to instead of drive to. We know that when people live in smaller multifamily units with shared walks, they use less power for heating and cooling than people who live in single-family houses."
But some worry the environmental benefits of HB 2001 would be undermined if the metro area responds by expanding the urban growth boundary, the invisible belt within which development must occur.

House Bill 2001 compels Oregon cities of more than 25,000 to allow buildings as large as four units in neighborhoods currently zoned for single-family housing. Large cities have until 2022 to come up with plans.

That could have a big effect on housing affordability but also the use of fossil fuels.

"The sooner cities are able to implement these changes, the sooner we will see those benefits to address both the housing crisis and the climate crisis," say House Speaker Tina Kotek (D-Portland).

The Sightline Institute, a Northwest-based sustainability think tank, projects that a shift from single-family dwellings to multi-unit buildings on one city block would result in about 20 percent less energy use by households in those buildings, assuming dwelling sizes were smaller.

And that doesn't factor in savings from reductions in miles driven. Increased density means more walking and less driving, resulting in less emissions from cars.

Another Sightline analysis found that increasing density by one-third on a block of 21 single-family homes could cut vehicle miles by 1,000 miles per household per year.

But the impact of the bill could be blunted. The real estate industry joined in supporting the bill thanks to a provision that could ease its push into the suburbs.

Every six years, Metro, the regional government responsible for land use planning, is required to determine if the Portland area has a sufficient inventory of buildable land. If not, Metro must expand the urban growth boundary.
But HB 2001 gives developers a new weapon in their fight to expand the boundary. It creates new math for how Metro calculates how much land is needed for housing. And it gives developers more opportunities to challenge Metro's decisions.

Metro is alarmed.

"The amendments demanded by the Realtors are part of their effort to force expensive sprawl onto farm and forest land, to rig the land use system in ways that turn Portland into Houston," says Metro lobbyist Randy Tucker. "While Metro opposed these amendments, we continue to believe that smart reforms to the system, like HB 2001, can improve housing opportunity while protecting the farms, forests and clean water we all value about this place."
Kotek doesn't see a problem.

"The intent of the bill was to address the barriers to more diverse development in cities, within urban growth boundaries," she says. "Oregonians value their land use system, and the intent of the bill was not to change the process for setting UGBs."

Mary Kyle McCurdy, deputy director of the land use nonprofit 1000 Friends of Oregon, says Metro's analysis was already "rigorous." "I don't think it's going to lead to different conclusions."

But the real estate industry likes the opportunity it created.

"[HB 2001] made significant improvements to how they calculate buildable land and housing needs," says Shaun Jillions, a lobbyist for the real estate agents. "That was the bigger carrot."

The changes got the real estate industry on board—and, with them, Republicans who might have been reluctant to vote for a bill championed by the Democratic leadership.

Michael Andersen, a senior researcher at the Sightline Institute, says HB 2001 could be a significant step forward. But that won't be enough to address global warming—Oregon must also restrict carbon emissions.

"Climate action requires every viable tool to reducing carbon," says Andersen. "One of those tools is to use carbon pricing to make the prices of our purchases tell the truth about environmental costs. Another of those tools is legalizing energy-efficient housing. We should do both."