Converting Offices to Housing
Drawing on consultations with 56 cities internationally as well as its own in-house research, Gensler created an algorithm that uses readily available data to compare an office building with best-in-class residential buildings. The algorithm runs over 50 variations for each building, tabulates its percentage of similarity to top-performing residential developments, and displays the results in a user-friendly dashboard format. It then tests the top picks, accounting for typical net-to-gross ratios, allocating average unit sizes based on location, estimating numbers of units to a building, and calculating how many elevators and what size service risers are required. “And it’s doing that in about five minutes,” says Paynter. “It’s allowed us to do half of Calgary in two weeks.” The speed of the analysis, along with $160 million from the City of Calgary in downtown revitalization funding (of which $36 million is earmarked specifically for this type of repositioning) has so far enabled about a dozen conversions to get under way.
Key factors the algorithm assesses include the building’s context, with maximum points going to buildings with cultural or heritage value that are located in mixed-use neighborhoods with access to green space, amenities, and transit. Building form also matters, with orthogonal shapes preferred. Among site-related factors, buildings on corner lots having at least 65 feet to adjacent mid- or high-rise neighbors have an advantage. Windows are ideally located on at least three sides, with extra points for south-facing glazing that covers at least 40 percent of the wall area. Floor plates with a minimum 40-foot depth, 8,000-square-foot area, and 9-foot floor-to-floor height, served by multiple elevators, earn top marks. Structure and servicing, ease of required upgrades, and adequate parking garner additional points.
A redevelopment completing construction this fall in Los Angeles, designed by Olson Kundig Architects with Large Architecture, ticks many of those boxes. Originally designed by Midcentury Modern architect Richard Dorman and built in 1964 as the Los Angeles International Design Center, the 10-story 8899 Beverly Boulevard is the tallest building in its dynamic, increasingly walkable neighborhood. Its conversion will create 40 condominium units, with eight new townhouses as a separate structure. “This type of project is the future of development in dense urban-infill areas, where undeveloped land is virtually nonexistent,” says Tyler Siegel, cofounder of Townscape Partners, the conversion’s developer. “And, in some respects, it represents the ultimate sustainable project, in that the entire building is recycled.”
Along with the building’s location, where the city has created incentives to boost residential and mixed-use development, factors such as the mid-rise height, generous floor-to-floor spans (by residential standards), views, and even balconies made what Siegel calls the perfect starting point.
From a design perspective, “the biggest challenge was also the most exciting,” says Tom Kundig, design principal: “how to maintain the integrity of the original Dorman building, but tie it in with a new function as a residential building.” The redevelopment expands the building footprint to 17,000 square feet (from a minimally viable 8,500) “while keeping the form of the original building legible, creating a dialogue between old and new,” Kundig says. Ribbon windows have been replaced with floor-to-ceiling triple glazing, much of it operable, with minimized frames and continuous flooring enhancing continuity between unit interiors and the balconies, terraces, and views beyond. Interior details, such as Kundig-designed leather-wrapped bronze door handles, honor the building’s historic association with design and its location in a design-branded district.
Working with an existing building often presents unique hurdles. In this case, the most significant was an extensive structural upgrade to meet current building codes—a necessity triggered by the building’s change of use. New 2-foot-thick concrete shear walls and column-reinforcing concrete wrap achieved current seismic standards. The decision to expand the floor plates with post-tensioned concrete slabs and new supporting columns, and to add a penthouse with a cantilevered steel structure, necessitated a new 5-foot-thick mat foundation beneath the entire building. Meeting design tolerances and resolving the junctions of old and new took painstaking attention to detail throughout. “Difficulty level 10,” says Siegel, pointing to a 1⁄2-inch base reveal for the glazing track, which required the old and new slab elevations to marry perfectly, as just one example.
Despite those difficulties, the renovation is achieving multiple values: giving a distinctive building (and its embodied resources) a new lease on life, darning a hole in the city’s fabric, and helping a neighborhood evolve. “This project presented an opportunity to reimagine an existing midcentury building for a changing urban landscape,” says Kundig. “I’m interested in architecture that tells an evolutionary story—reflecting changes in how we live, and how we plan cities.”