April 11, 2025

LMN prepares Longacres master plan for Unico with hotels, 3,000 units

Rendering by LMN [enlarge]

Looking northwest, the two Kaiser Permanente buildings are bottom left; Oakesdale is at right.

In December of 2021, with the pandemic still looming large in the rear view, Unico Properties made an audacious $100 million bet on Boeing's underutilized Longacres Campus in Renton . Since that purchase, there have been two big milestones: the rebranding of the south building as Sounders FC Center at Longacres; and the $85 million sale of the north building, last year, to Alaska Airlines.

So what to do with the remaining 120 acres at Longacres?

Unico mentioned residential use, a hotel and more offices back in 2022. Its master planning effort began in earnest the following year. Several new parcels have since been created for future development. The main project goes by 1901 Oakesdale Ave. S.W.; new addresses will emerge later.

The city of Renton received that permit application in February. LMN prepared the master plan, which envisions a timeline of 10 to 15 years to full build-out. If realized, it would look something like this:

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The city hasn't yet issued a formal public notice for the Longacres master plan. Eleven new apartment buildings could have 2,899 units, plus some retail. New commercial construction would hit around 2.2 million square feet.

• New commercial construction would hit around 2.2 million square feet. Some combination of medical offices, other offices, retail and restaurants would contribute about 1.7 million square feet to that figure above.

• Eleven new apartment buildings could have 2,899 units, plus some retail. Those would have around 2.3 million square feet. Parking look so to be structured or below grade.

• About 62 acres would be preserved as open space, with new landscaping and amenities. The existing central lake and trails would be preserved.

• Two hotels might total 350 rooms. A possible music venue would accommodate 8,000 guests. Around 6,500 new parking stalls would be created. (Existing surface lots would be trimmed or disappear entirely.)

Add in the existing two old Boeing buildings, plus some wiggle room, and you get a gross figure of nearly 5.8 million square feet.

Unico's team also includes GeoEngineers, geotechnical; Coughlin Porter Lundeen, civil engineer; TenW, traffic engineer; Salish Restoration Associates, arborist; Bush Roed & Hitchings, surveyor; Hewitt, landscape architect; and WH Pacific, additional surveying.

How might the Longacres project be phased?

The west side of the campus, bounded by the railroad tracks, is quite walkable to Tukwila Station, with its Sounder service, and RapidRide F Line stop.

Thus, Phase I might start on the northwest corner (south of Interstate 405), with a hotel, medical office building and three apartment buildings. (An assisted-living building for seniors is also an option there.)

Phase II could then add more apartment buildings, continuing south in an L-shape to the Kaiser Permanente campus. A second hotel could go in the middle of the campus, just north of the lake. At the same time, on the far east side (and east of Oakesdale), the concert venue might also be developed. That would be south of the existing Bright Horizons childcare center.

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The west side of the campus is walkable to Tukwila Station, with its Sounder service, and RapidRide F Line stop.

The final Phase III, on the southeast corner, would add some new combination of offices, medical offices, light industrial or whatever the market then dictates. One more commercial building could also go north of the Alaska Airlines building, close to the freeway. New interior streets and driveways would be added along the multiyear process.

The city hasn't yet issued a formal public notice for the Longacres master plan. That should follow this spring or summer, along with public meetings and a comment period.

Unico's application says that early work might begin this year; that likely means grading, surveying and demolition of some small random out-buildings.

Future development partners and financial partners would seem likely for a projects of such scale. The new parcels would allow Unico to sell and retain new developments along the way.