December 2, 2019

SLI offers more details about plans for First Hill prefab tower

Rendering by Sustainable Living Innovations [enlarge]

SLI is asking the city for a reduced setback from the sidewalk to allow its steel exoskeleton method of construction.

As the DJC first reported this summer, “kit of parts” developer Sustainable Living Innovations is planning a 21-story, 176-unit apartment tower at 901 Madison St. on First Hill.

SLI says it has the corner under contract to buy. It's being offered for $5.4 million by Rick Sanders of Wyse Investment Services. It totals 7,680 square feet.

A one-story building on the site, now home to the Quarter Lounge, would be razed.

SLI says that 47 units would be affordable. The project hasn't yet entered design review. However, an early request to the city for a right-of-way setback exemption indicates where it's headed.

SLI is a venture of architect CollinsWoerman and Renova Capital Partners of Denver. The same team owns a corner at 303 Battery St. in Belltown, where it's planning a 15-story, 112-unit building with many energy-saving features. And plans recently emerged for the Mercer Mega Block, which Alexandria Real Estate plans to buy from the city for over $143 million. There, at 615 Dexter Ave. N., SLI is planning an 18-story apartment building with 364 units (over half of them affordable).

Those and 901 Madison would all employ the same modular or prefab method, with pre-assembled wall and floor panels manufactured off-site. Each unit is essentially a clone in a stack. They're jacked into place, from top to bottom, from within a steel exoskeleton — which itself allows no setbacks within the frame.

The 901 Madison plan can't give the city its desired five-foot setback from the right-of-way (Madison Street and the sidewalk) because, SLI writes, “The site is on a corner lot. Sharing the existing northeast property line with the Bloodworks Northwest building. This building also makes it unlikely for further improvement of the ROW along the block.”

Instead, a two-foot building setback from the sidewalk is proposed.

SLI writes, “The technique used for this type of construction requires that the primary structural components remain in the same position vertically all the way up the building. The structural setback at grade of two feet is optimal to meet the transfer of structural load for the building.”

The six-story, L-shaped Bloodworks building, at 921 Terry Ave., isn't set back from the property line (i.e., the sidewalk). It was constructed in 1983, under an old building code. The 901 Madison site essentially lies within its L-shape.

SLI writes, “The proposed setback of five feet would remove the ability for the supporting ground floor structure to carry the loads of the building above. Moving the structure back further to accommodate the five-foot ROW would require significant expense to the project, rendering it infeasible. This includes reduction of the total unit count.”

If SLI receives a setback exemption and the plan proceeds, it would include about 1,500 square feet of retail. Two levels of underground parking with 36 to 48 stalls would be accessed from Ninth Avenue. The parking would be done via a mechanical stacking system.

Seattle is now starting to see such parking on small, tight sites like the Spire condominium on the triangular site at 600 Wall St.

Early renderings of 901 Madison strongly resemble 303 Battery, with a crown of solar panels above the roofline. The building size above grade is listed at 146,500 square feet. A bike room is indicated.

SLI also indicates it'll pursue LEED or Built Green certification — those categories overlap with the city's Living Building Pilot Program, which 303 Battery will employ. The 901 Madison plan also mentions that same pilot program.