As with officials in Toronto and Minneapolis, Portland planning commissioners appear poised to embrace gentle density.

In a series of straw votes last week, the planning commission endorsed a number of policy changes designed to cap the size of new single units, re-legalize structures that include more than one unit inside and allow buildings to get slightly bigger to include multiple units, Sightline reports.

The commission also recommended increasing the maximum number of allowable homes on a (previously single-family) lot to three or four.

The commission is an advisory body, so the changes still must go before the City Council. But its recommendations carry some weight, especially because the Portland City Council has been leaning pro-density in recent years, according to the website.

“The goal is to reduce demolitions of one small house for one big house, and incentivize things the public has an interest in having more of: homes, especially less expensive homes, especially ones that rehab old structures instead of demolishing them,” Sightline reports. The changes reflect a vision for the city “where more expensive detached homes and more affordable small plexes are all mixed together,” according to the website.

Minneapolis officials have been debating a similar long-range vision, As Next City has covered. Mayor Jacob Frey has voiced strong support for so-called “fourplexes” in single-family neighborhoods, with the goal of increasing density without massive new developments.

The concept is an example of gentle density — i.e., increased density from duplexes or garage apartments in areas zoned mostly for single-family homes. In Toronto, officials have also been eyeing the city’s network of alleys — or laneways — as a source of second units in neighborhoods that generally keep to one home per lot.

In Portland, planning officials see the smaller homes as a win not just for increased supply, but for sustainability as well.

“For all the talk about, ‘We can’t fit into this 2,500 square foot house,’ I kind of think, well, we did for most of human history, in houses half that size,” commissioner Eli Spevak said last week, according to Sightline. “I also think about the carbon issues. Oregon has studied this more than any state. The biggest carbon impact of new construction, over the lifespan of a house, is how big it is. Seventy, 80 percent of the carbon impact of a house is heating and cooling the space. … Attached housing is great for that also, and this code supports both those things: attached housing and small homes.”

Rachel Dovey is an award-winning freelance writer and former USC Annenberg fellow living at the northern tip of California’s Bay Area. She writes about infrastructure, water and climate change and has been published by Bust, Wired, Paste, SF Weekly, the East Bay Express and the North Bay Bohemian

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