For years, Portland, Oregon has gained attention for becoming one of America's best cities to live and work. But as its popularity increases, so does its cost of living.

A recent report from The Milken Institute ranked Portland as one of the most economically promising cities in the U.S. for its environmentally-friendly lifestyle, spunky neighborhoods and tech jobs that rival those in Silicon Valley but come without the hefty cost of living. But longtime residents who made the city the funky place where everyone wants to be say they can't afford to live there anymore, and that affordable housing options are few and far between.

Portland locals are all too familiar with rents that have been rising faster than ice in a cup of cold brew. The trend shows no signs of stopping anytime soon.

"Prices are outrageous," said Bryan Downes, a former professor at the University of Oregon's Department of Planning, Public Policy and Management. "There's a major transformation going on here."

Bob Pool via Getty Images Snow-covered Mt. Hood looms over buildings in downtown Portland, Oregon.

SURGING RENTS

Some economic analysts say the lack of housing is due to migration from other parts of the country. A handful of community planning experts say affordable options are dwindling due to swanky new apartment buildings. And still others, including real estate brokers, blame tech companies moving to the city for all sorts of woes.

NEW NEIGHBORS

Companies including Apple and Google have offices in town, bringing educated young employees along with them.

Hewlett Packard-owned Aruba Networks, a mobile networking enterprise, recently opened an office in Portland as an extension of its hub in California.

"There were a lot of resources there we could tap into [in Portland]," said communications director Pavel Radda. "And of course, the cost was less than Silicon Valley."

The influx of new renters in Portland drives up demand and prices for a limited amount of rental units. Houses that real estate agent Kim Minasian Sparks rented for $2,295 per month last year are now up to $2,800, she told HuffPost. It's an incredible jump.

The average one-bedroom apartment on Sparks' list rents for $1,400 per month. According to Zumper's National Rent Report, the rent is much less than the one-bedroom median rent of $3,530 in San Francisco, but within striking distance of Los Angeles' one-bedroom median rent of $1,830 .

Anthony Pidgeon via Getty Images Festival in Cathedral Park, below the St. Johns Bridge in the St. Johns neighborhood of North Portland.

LOW-INCOME RESIDENTS HIT HARDEST

Heidi Martin is a loan officer at the Portland Housing Center, a nonprofit that launched with financial support from the city. The organization secures houses for first-time homeowners. She says that while most of her clients have low incomes, it's also tough to find affordable housing for young professionals with middle incomes.

"Supply and demand has driven prices way, way up," Martin told HuffPost. "We don't know why we have this housing shortage, but we do."

"There are multiple factors, and what’s going on varies from neighborhood to neighborhood," Downes told HuffPost. "That's why people have a hard time saying it’s a function of just this or that."

Some neighborhoods lack the affordable housing that low-income residents need, and others are attracting enough middle-class residents to drive prices way up.

Even if a renter secures a price upon signing, it could change in a snap. In November, after a string of renters were kicked out of their apartments with little-to-no notice, city officials approved a rule that landlords must give tenants at least 90-days notice before evicting or raising rent by more than five percent.

Justin Buri, from Portland's Community Alliance of Tenants, says renters need more warning. His organization is pushing for one-year notice on rent increases, along with a one-year ban on "no-cause" evictions.

"Landlords can pretty much raise rent as much as they want as quickly as they want," he said. "And that’s tearing our communities apart."

Rainer Grosskopf via Getty Images Portland Skyline and Hawthorne Bridge at sunset.

FINDING SOLUTIONS

The city is indeed working to help residents with rising costs. The Portland Housing Bureau partners with groups like Habitat for Humanity to secure homes for those who have trouble finding them, program manager Andrea Matthiessen told HuffPost. The Portland Housing Center allocates funds to help with down payments. Both options, however, are reserved for locals with especially low incomes.

For middle-income residents, help is harder to find. A visit to the Portland Housing Center will get them advice on how to find a home, but not any financial help. First-time homebuyers who meet certain income requirements can qualify for a Mortgage Credit Certificate, a federal tax credit that provides residents with increased disposable income for housing.

Co-working spaces like Collective Agency provide office space for a relatively affordable price. "Some smaller companies work out of here rather than a standard office," staff member Heather Anacker said.

But no matter where residents live or work, experts from many slices of Portland life say it's a crisis of too much demand and too little supply.

"There just aren't enough homes for people, and wages don't keep up with the cost of housing," Matthiessen said. "It's a bit of the perfect storm."

Land is hard to come by in Portland proper, and existing communities prevent the city from expanding further.

Oregon officials also have a chance at taking what Robert Parker, a researcher with the University of Oregon's Department of Planning, Public Policy and Management, says would be a solid step towards a solution.

The state has a prohibition on mandatory inclusionary zoning, which would allow local governments to require building developers to set aside a certain amount of new units as affordable housing in new constructions.

The state legislature has shot down inclusionary zoning bills before, but they plan to consider a new one next month, said Eden Dabbs, a spokesperson for the Portland Bureau of Planning and Sustainability.

It's a small change that could have BIG results.

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