June 8, 2021

Shorenstein moves toward MUP for SLU offices, with mass timber construction facing code challenges

Rendering by Weber Thompson [enlarge]

This perspective looks southwest at the planned building.

Shorenstein Properties and Weber Thompson are planning a new office building at 235 Ninth Ave. N. in South Lake Union. The project, dubbed 9North, will replace some old industrial buildings on the corner of Thomas Street.

Another design review may be pending, but the developer has applied for a master use permit. The project now stands at eight stories, the top floor deemed a solarium, with about 110,000 square feet of offices. The entire project, parking included, totals about 160,000 square feet. The Mandatory Housing Affordability fee is estimated at about $1.25 million.

Shorenstein still hopes to make the building a mass timber project, but the city — including the fire department — would have to approve a code variance. At issue is reconciling old city codes with the fairly new state building code update that allows a Type IV C mass timber building up to nine stories and 85 feet.

Shorenstein wants 9North to be about 110 feet tall, using cross-laminated timber for the structure above its concrete base. If code departures aren't approved, meeting notes indicate the developer would opt for all-concrete instead. Regardless, 9North will pursue LEED gold certification, with rooftop solar panels and other green features. Shorenstein, of San Francisco, hopes to begin the demolition, excavation and shoring next spring. Construction might then begin next summer, with completion in 2023.

The team also now includes Swinerton, pre-construction services (and likely contractor); Coughlin Porter Lundeen, structural; KPFF Consulting Engineers, civil; Glumac, MEP and LEED consultant; Hansen Surveying & Consulting; McCullough Hill Leary, legal services; RDH Building Science, envelope; Lerch Bates, elevators; and GeoEngineers, geotechnical.

Floor plates look to be a little under 16,000 square feet on levels two through seven. Two levels of underground parking will have about 59 stalls; the garage entry will be from the alley to the west. About 53 bike stalls are also planned.

The roof deck would have about 1,970 square feet. About 980 square feet of retail/restaurant space is indicated on the corner, with a small outdoor plaza suitable for outdoor seating.

Shorenstein paid $17 million for the 18,000-square-foot property last year. Shorenstein is also a partner with Wright Runstad in the Spring District, in Bellevue.