Portland’s Metro Council recently had a briefing about growth in the Portland  over the next 20 years. The numbers are even bigger than Seattle’s growth numbers. From the Portland Tribune:

Portland planners say the city can house half the people expected to move to the metropolitan area during the next 20 years. They predict 123,000 new housing units will be built in Portland by 2035.

The Metro Council heard that prediction from Portland Bureau of Planning and Sustainability Director Susan Anderson and Principal Planner Tom Armstrong last Tuesday. Anderson and Armstrong had been invited to give the council an overview of the comprehensive plan update that will guide Portland’s growth until 2035.

“Portland has essentially half of the region’s capacity over the next 20 years,” Anderson said.

Seattle’s growth is modest in comparison. This is from the capacity report produced by the Department of Planning and Development (DPD) in preparation for revisions of the Comprehensive Plan.

State and regional agencies estimate that Seattle will add 70,000 housing units (120,000 people) and 115,000 jobs between now and 2035 – an increase of 20% population and 23% in jobs.

In Portland, the discussion is similar to the one we’re having here. Recently, Mayor Murray issued a challenge to his Housing Affordability and Livability Agenda (HALA) Committee to produce 50,000 units of housing, 20,000 units of subsidized housing and 30,000 non-subsidized units. That level of production is ambitious according to a review of housing production data done by the Coalition for Housing Solutions.

According to data from the King County Assessor (see graph on page 3), there has never been a ten-year period in which Seattle has produced 50,000 units.  The closest Seattle has approached this rate of housing production was in the post-War boom of 1945-1956, during which 34,889 units were constructed (see chart below).

A similar objection to the ambitious housing numbers has been voiced in Portland too. Also from the Portland Tribune story:

But the housing projection is based on a controversial premise. According to [planners Susan] Anderson and [Tom] Armstrong, the vast majority of the new housing — 75 to 80 percent — will be multifamily housing. For that to happen, multifamily construction will have to more than double the rate of the past 14 years.

BPS defines multifamily housing to include apartments, condominiums, auxiliary dwelling units, duplexes, rowhouses and townhouses. The vast majority are apartments and condominiums. According to the Bureau of Development Services — which issues construction permits — 31,563 such permits were issued between 2001 and 2014.

That’s an average of 2,254 such permits a year. But to reach the draft comp plan update goals, between 4,612 and 4,920 such permits will have to be issued every year for the next 20 years.

That rate has been questioned by the Home Builders Association of Metro Portland, which does not believe such a building boom can be sustained for so long. In fact, the highest number of multifamily permits issued so far was 4,486 last year. The home builders argue that much of the construction is the result of pent-up demand caused by the slowdown during the Great Recession, not a trend that will increase and continue for two decades.

And what’s the emerging worry in Portland?

A greater concern to Anderson was the increase in housing costs likely to result from all the new construction. In fact, several recent studies have found Portland already is becoming increasingly unaffordable. A recent study by the Zillow real estate economists found that 50.3 percent of Portland homes for sale are unaffordable by historic standards. Zillow also found Portland rents increased 7.2 percent last year, the fifth-highest increase in the country.

“People with money are going to keep moving to Portland, and I’m worried sick that a lot of families are not going to be able to continue living here,” said Anderson, who suggested lower-income people may need to move to communities like Beaverton and Milwaukie.

Sounds familiar. It will be interesting to watch how Portland struggles with the same issues Seattle has been over the last few years. Will Portland choose to increase housing supply? Or will it make more rules so that building all the housing planners say they need will be more costly to build, fulfilling the very thing planner Anderson is worried about: higher costs. Portland has always claimed to be a city with a plan, not afraid to promote bikes over cars and energy efficiency for buildings. But they will have to overcome some of the same misconceptions about housing price to avoid our stumbles in Seattle, making it harder to do what we should, build more housing.