By Julie Snow, Matthew Kreilich, Natalya Egon, Matthew Tierney, Christina Stark, Kar-Keat Chong & Mike Heller (Snow Kreilich Architects)
The greatest challenge – and the greatest asset – of using existing rooftops as the “plots of tomorrow” is one of contextual response. Each building comes with a narrative past and unique physical characteristics, both informing the design of any future building. Therefore the goals of North Wood are twofold: to use context (i.e. existing structure, climate, views, etc.) as a formal design driver and to test a tall wood structure as a means of balancing context with innovation.
North Wood is a high-density wood tower concept proposed for a historically significant 1920s two-story concrete and masonry building in the business district of Minneapolis, Minnesota. Minneapolis is a prime location for a tall, wood, residential structure for a handful of reasons. Mid-size cities in North America are growing at a faster rate than more populated urban areas; by densifying the existing downtown core now instead of later, we can prevent another wave of urban sprawl and preserve low-density historic buildings from development-driven demolition. Additionally, the proximity of Minneapolis to Spruce and Fir forests creates a lower embodied energy for LVL as a building material and also links with Minnesota's history as one of the major softwood producers of North America. Finally, Minneapolis has one of the largest annual temperature swings in the populated world; the extreme shifts from frigid and snowy winters to hot and humid summers provide an ideal testing ground for innovative building technologies.
The existing two-story building was over-structured in anticipation of 8 additional concrete floors that were never constructed. A lighter wood structure could provide up to 20 additional stories. Respecting the historical street façade while tapping into the most robust columns of the existing structural grid, the addition is stepped back one bay from each façade. Select floorplates are extended past the structural grid to provide outdoor amenity space and open views of the public commons to the east, the nearby pedestrian Nicollet Mall to the west, and the downtown skyline to the north.
Structurally, a wood shear core extends from the street level up through 7 floors of hotel, 11 floors of residential condominiums, and two double-height amenity floors. Floor/roof diaphragms free span from the core boundary to the structural façade. Rather than sizing larger vertical members for a consistent grid, secondary vertical members are densified in prescribed areas for dead/wind loading, increased privacy, and solar shading. The resulting façade composition is the result of testing in depth, this context. When applied elsewhere – whether across the globe or across the street—it would have an alternative appearance.