SPANISH: Crafting a welcoming space through natural materials at 2100 Pennsylvania Avenue

SPANISH: Marble melds nature, architecture, and sculpture together, elevating placemaking to its highest levels at 2100 Pennsylvania Avenue, a LEED Gold, mixed-use development on the northeast corner of George Washington University (GWU) campus.

The design embraces the site’s challenging geometry, carefully establishing uplifting public space within encircling v-plan floor plates. The inviting 3-story entrance lobby rises into a grand 10-story atrium – a “forest” of daylit wood and stone, animating the prominent corner of Pennsylvania Avenue and 21st Street – visible over a mile away. The playful and signature undulations of the building – emulating the iconic streamlined Flatiron Building and Barcelona’s Casa Mila – culminate in the public interior, where a sweeping marble stair carries the rich pattern of varied stone textures from the street level lobby up 12 feet into the atrium amenities level.

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Considering the need for a beautiful and durable material in all high traffic areas, the team chose natural stone. Stone procurement for 2100 Penn Ave started with exploring an array of medium to dark-colored stones to complement the brighter white oak and etched glass walls, with deeper tones and colors emulating a riverbed. For the exterior storefronts and entry paving, the team selected flamed Zimbabwe Black granite. Following the visit to marble quarries in central Turkey, the design team selected Turkish Dark Olive marble for the balance and majority of stone areas: the public lobby, grand stair, atrium, all public bathrooms, elevator cabs and lobbies.

After the quarry visit, PC&P made a preliminary review of blocks and associated slabs at the fabrication plant in Bilecik, Turkey to confirm the acceptable ranges of needed material. Within a few months, representatives of the project team, including the owner, architect, installer, and GC convened at the Bilecik fabrication plant, reviewing, and approving the balance of blocks, slabs, paving finish strategy, future dry-lay review process (which eventually totaled 5 visits – 2 while under strict COVID restrictions), packing sequence and shipping.

Unprecedented levels of fabrication continued through a thorough, 100% dry-lay review process, including all dimensional stones, curving slabs, and the grand stair. The design team refined the design multiple times to optimize the blending process. The paving design included four different sized pieces to optimize the highest yield per slab. By incorporating a regular high-honed accent, the stone paving had regular breaks that afforded better blending tolerances for the entire project. Special wood scaffolding was employed to facilitate the complete dry-lay of all walls, stairs, ramp, and paving stones together.

The 100% dry-lay reviews helped assure a smooth installation, but there were still issues of unavoidable cupping. The most challenging parts to finish were the ramp and grand stair walls. In select areas, the installer had to grind and refinish the leather surface to match throughout. This proceeded after a careful review of additional mockups and input from the installers, architects, and owners.

2100 Pennsylvania Avenue showcases how to conceive and implement natural stone to the highest levels of craft today, elevating architecture to new levels of uplifting placemaking.