John Holmes, AIA, and Mack Selberg, AIA, have been talking for years about designing a building based upon fractal geometry. So, when some forward-thinking developers approached Holmes to do a multifamily high-rise in Portland, Ore.'s Pearl District, he called upon his old friend for help. Their design for 937 Condominiums uses random mathematical patterns to determine the placement of windows and balconies. “We then chose sustainable strategies that reinforced the building design philosophy,” Selberg explains.

One strategy they chose was to place living and sleeping areas along the exterior walls, maximizing natural light. And they carved out interior rooms working within the windows' fractal patterns. The projecting balconies on the façade will also serve to shade the generous glazing.

Those erratic windows and balconies will overlook 4,000 square feet of plantings atop a plinth of retail spaces below. The green roofs should produce oxygen, help cool the air, and filter and reclaim stormwater runoff. “It will act more like an open planted field than a building,” Selberg says of the project, which is slated for completion by the end of the year.

project: 937 Condominiums, Portland, Ore.

key green strategies: Photovoltaics, green roofs, local materials, rainwater harvesting, construction material recycling, bicycle parking, high-efficiency heat pumps, and dual-flush toilets

exterior architect: John Holmes, AIA, Holst Architecture, Portland

interior architect/sustainability consultant: Mack Selberg, AIA, Ankrom Moisan Associated Architects, Portland

developers: Patrick Kessi and Goeff Wenker, 937 Group, Portland

general contractor: Greg Martin, Andersen Construction Co., Portland

project size: 946 square feet to 2,494 square feet per unit

site size: 0.5 acre

construction cost: Approximately $200 per square foot

sales price: $339,000 to $2.25 million per unit

units in project: 114

renderings: Courtesy Holst Architecture