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Rounding curves; avoiding debris
Built more than 80 years ago and listed on the National Historic Register, the team had to be
“convinced beyond a shadow of a doubt,” according to Lansdale, that the existing structure and its foundation could support the load of both a 9th floor penthouse—which would house the elevator machine room, mechanical systems, etc.—and the new event space. Investigating load and accruing wind shear, structural engineers Thornton Tomasetti bored through existing footings, into the soil, to produce a detailed analysis.
"I will say it wasn’t an immediate response from them to say ‘no problem,’” Lansdale conceded, adding that the prospect of underpinning the entire
building, to make it structurally sound enough to support the event space and penthouse, may have made the project cost-prohibitive. “That was the first hurdle,” he said when the structure was ultimately deemed capable.
A dearth of building information from the 1920s precipitated a column survey next by Thornton Tomasetti and HITT Contracting, which revealed between 55 and 60 existing columns, to comply with D.C. construction mandates that the new steel columns had to land directly on the center line of the old ones. “It was a tremendous piece of design and engineering
on behalf of the designer and contractor working together,” Lansdale said, noting only two locations were missed. “If you fabricate something that doesn’t fit at all, you’ve really lost time and energy,” he said.
Citing another design challenge, Lansdale said among zoning requirements was that the new structure had to have a 1:1 setback from the existing roof parapet. With the desired ceiling height to be quite formidable, the space would become “skinny” and almost unusable. Embarking on a series of studies to maximize the space’s volume and meet the requisite 1:1 setback, the result was an 8-ft. perimeter roof edge line, but with a vaulted skylight system that reaches about 13 feet at its apex.
Staying on track
Usual (and not so usual) zoning quagmires included a conflict between the District’s Comprehensive Plan, which allowed for a story to be added, and existing zoning, which precluded any additional height. A rezoning application ensued before Lansdale, et al, could submit to the Commission of Fine Arts and Historic Preservation Review Board. Where the separate penthouse construction was concerned, a Board of Zoning Adjustment application was required, with the letter of the law stating that this structure, also, needed to have a 1:1 setback, but from the addition beneath it. “There was no way to build (the penthouse for systems and machines) without a waiver of that requirement,” Lansdale affirmed, noting it was ultimately achieved, though the equivalent of a short prison sentence—beginning in 2007—was spent navigating zoning and review board processes.
With 11,000 s.f. of separable space, in addition to a kitchen, that becomes five function rooms, public spaces and restrooms, design features and finishes include Crema Marfil marble, custom stained wood, Charles Edwards
brass lantern fixtures and fabric wall panels. The addition’s perimeter faces 16th and H Streets and has what Lansdale said is a giant French door system with double-hinged doors that fall back on themselves, leading out to a balcony with sparkling vistas.
“This was a good project to do because architecturally, it really cleaned up the roof compared to what it was before with a tent and exposed mechanical system,” Lansdale said, noting the first events were accommodated in January. “The penthouse part of the design organizes and takes everything out of sight, and if you’re standing on the street, the only thing you see is a set back 9th floor event space that is actually very beautiful. It’s a completely different ‘skyscaped’ look for that particular address.”
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2 comments:
Great article. Thanks!!
Great post, wonderful to see the Pavilion Lanterns insitu.
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