Plans are moving forward for a $45 million, 13-acre business hangar campus at Hillsboro Airport — one of the largest proposed developments at the site in a decade and part of what the Port of Portland describes as a step toward making Hillsboro economically self-sustaining.

But while the Port touts the project as an economic win, environmental advocates argue it would do more harm than good — benefiting an affluent few at the expense of the community and the environment.

On Wednesday, April 9, the Port of Portland Commission approved a 35-year ground lease agreement, with an optional 10-year extension, with HIO Development LLC to transform vacant land at Hillsboro Airport into a private campus for corporate and general aviation jet travel.

HIO Development is a subsidiary of Sky Harbour Group, a company that develops, leases and manages general aviation hangars at airfields across the United States. Sky Harbour currently operates or is developing sites at 16 airports in 12 states, with Hillsboro marking its third West Coast project and first in the Pacific Northwest.

No direct investment would be required from the Port, which oversees Hillsboro Airport, Portland International Airport and other general aviation and marine facilities in the Portland metro area.

What’s planned for the site?

Located on the airport’s eastern edge — bordered by Airport Road and Brookwood Parkway — the project calls for two rows of interconnected hangars, a shared aircraft ramp, fueling stations and vehicle parking. Under the agreement, HIO Development will lease each hangar to a single client on a one-to-one basis.

The project will be built in two stages: The initial buildout will cover about 343,500 square feet, and a second expansion will add another 230,000 square feet within five years of the first stage’s completion.

Construction is expected to begin in early 2026, with the first stage targeted for completion in 2027, according to Port documents. Under the lease terms, HIO Development will have an 18-month window to complete construction rent-free.

Once operational, the Port will collect fair market rent, adjusted every three years according to airport policy. According to Stephen Winkle, the Port’s senior manager of general aviation and airside properties, the current rental rate would generate an estimated $15.25 million over the base term.

Environmental pushback

During public testimony, environmental advocate Miki Barnes, founder of Oregon Aviation Watch, urged commissioners to reject the lease, warning the project would fuel pollution and carbon emissions to serve a select few.

“This proposal will primarily serve the millionaire and billionaire class of high flyers whose lavish travel habits and lifestyles will further degrade the public health, environment and biological diversity in Washington County,” Barnes said.

She argued the expansion would compound “noise, lead emissions and toxic pollution” already affecting neighborhoods near the airport due to flight schools, private aircraft and other general aviation traffic.

“At a crucial juncture in the history of this planet — when many Oregonians are making a concerted effort to reduce their carbon footprint by driving less, using public transit, bicycling, walking and supporting high-speed rail options — the Port of Portland, rather than advocating for a significant reduction in air traffic, is promoting aviation growth and expansion on behalf of a wealthy few,” Barnes said.

The lease includes a 180-day due diligence period for the developer and remains contingent on the completion of a National Environmental Policy Act review.