September 9, 2025

No MUP, but 29-story SLU apartment project could be yours to build

Rendering via Weber Thompson [enlarge]

Looking northwest, the potential midblock assemblage has two owners.

Since the fall of 2022, Heartland has been advising Union Church and its South Lake Union neighbor on a possible sale and redevelopment plan. To aid in the effort, architect Weber Thompson has an early high-rise apartment proposal at 415 Westlake Ave. N. That might yield 342 units in a 29-story tower.

There is no master use permit, but Heartland recently put the midblock project on the block. The asking price is $25.5 million. The brokers are Tyson Heriot, Chris Fiori and Doug Larson.

An initial design review was held in early 2023, but the city no longer requires design review in that part of town. Meanwhile, new apartment construction has slowed to a trickle in the past few years, with perhaps a half dozen Seattle projects breaking ground this summer.

Fewer and fewer cranes now dot the downtown skyline, as multifamily developers seek to open new buildings during the summer leasing season — but not break ground on new projects. In its recent third-quarter multifamily report, RentCafe/Yardi Matrix says our city should see about 3,950 units delivered this year, down 27% from last year's number.

The same report places greater Seattle, including the Eastside, at 13th on the national list for apartment deliveries this year, with 11,196 units. Unsurprisingly, topping the list is New York, followed by a half dozen Sun Belt cities.

Despite a post-pandemic slowdown in construction, Kidder Mathews' recent apartment report says that supply and demand aren't terribly mismatched. The greater Seattle vacancy rate stood at 7.1% at the end of the last quarter, says KM. Rents have grown modestly, but in line with supply, over the past five-odd years.

Kidder's Dylan Simon optimistically predicts, “The Seattle market is showing signs of renewed balance, with rents trending upward and vacancy falling — a hint that leasing demand is keeping pace with supply.”

As for the future supply in SLU and the Denny Triangle, Holland Partner Group is above ground on its 45-story, 442-unit Sloane, which should wrap late next year. Westbank's tardy two-tower 1200 Stewart project, with about 1,014 units, should open at some point next year. (Its cranes aren't yet down.) Concord Pacific and HB Management's two-tower Seattle House could add another 1,130 units next year or in 2027. And Onni Group recently started its 48-story, 478-unit project on the former 13 Coins restaurant site, next to the former Seattle Times block.

So, back at 415 Westlake, add another year to secure a master use permit, followed by the land sales; then add three years for construction, and delivery might come by 2029 … when that cluster of high rises listed above is presumably full of tenants — if demand continues its slow and steady rise. The timing could then be right for a proven high-rise developer like Holland, Skanska, AMLI or Quarterra to pocket 415 Westlake now, then build later. Total project size is estimated at 328,400 square feet.

The DJC first reported the Union Church plan three years ago. It has occupied an old warehouse since 2012. The neighboring tear-down 411 Westlake building is owned by the former proprietors of Honeychurch Antiques; they subsequently leased it to Evergreen Goodwill, which closed that store exactly a year ago. A doggie daycare business recently filed an occupancy plan there, likely with a short-term lease in mind.