Earlier this month, Oregon’s legislature passed House Bill 2001, a measure that will require cities of more than 10,000 people to permit duplexes in areas currently zoned for single-family usage.
The bill, which received bipartisan support, is set to go before Gov. Kate Brown, D-OR, who is expected to sign it, therefore positioning Oregon as the first state to ban single-family-only zoning.
“Hypothetically, the bill could help create 14,000 new homes—the equivalent of an entire spring’s worth of new listings in the Portland metro, which would nearly triple the available housing supply in the area—if all the new homes were built at the same time,” Redfin writes.
In order to determine this, the company calculated that there are roughly 500,000 single-family homes in the Portland metro area. Then they assigned each property a “redevelopment score” of 0 to 100, with 100 having the highest potential for redevelopment.
Redfin then decided that about 7,000 homes have redevelopment scores of 75 to 100, making them more likely to be either demolished or rebuilt.
“The homes that are likely to be redeveloped would be turned from single-family homes into duplexes, triplexes, fourplexes, townhomes or cottage clusters,” Redfin writes. “We assumed that on average, one home on a lot with high redevelopment potential will be turned into three homes.”
According to the company, there are currently around 8,000 homes for sale in the Portland metro. If 14,000 new units all came on the market at once, Redfin claims it could nearly triple the total available inventory.
“Portland has massive amounts of incoming residents, especially from Seattle and the Bay Area, and not enough new homes being built to keep up with demand. The homes that are being built are mostly unaffordable for the typical local,” Redfin agent Matt Novak said. “Portland’s housing market needs a workable way to increase housing density so new and existing residents can find affordable homes that aren’t too far away from the city center.”
Novak says adding duplexes, triplexes and townhomes, along with some backyard accessory dwelling units is one way to help keep the city’s housing costs affordable for people who aren’t able to spend more than a half-million dollars on an expensive home.
Note: In order to calculate Portland’s market potential, Redfin created a model to determine which properties in Portland were most likely to be redeveloped.