In the heart of Washington, D.C., the architectural landmark, 2050 M Street, stands as a pioneer transcending traditional norms with its distinctive design. Spanning 41,800 m² (450,000 sf), this structure is a fusion of modern aesthetics and architectural tradition, redefining the city’s skyline.
Washington, D.C., is characterized by a duality in architectural styles—the heavy masonry structures reflecting Beaux Arts, neoclassical, Art Deco, and brutalist influences, and the sleek modern buildings with transparent glass facades. Although the structures have matching scales due to zoning codes, there is an aesthetic dissonance created between them.
Designed by REX with Kendall/Heaton Associates as the executive architect, 2050 M Street sets a new benchmark for premium office spaces. The building’s curtain wall, devoid of obstructive mullions, achieves transparency with floor-to-ceiling glass, introducing a novel architectural paradigm that blends the advantages of an all-glass structure with the modulation of a high-relief facade.
The exterior boasts 978 uniform insulated-glass panels, each with a subtle curvature using a bending tempering furnace. This curved glass eliminates structural mullions, reducing outer layer thickness and enhancing transparency. Perimeter columns are strategically recessed 3.8 m (12.5 ft) from the facade, and the ceiling narrows towards the exterior, accentuating the structure’s airy quality. A reflective pyrolytic coating on the exterior and a low-e coating within the glass cavity manage solar heat gain, creating a kaleidoscopic effect.
In stark contrast to the crystalline exterior, the lobby offers a luxurious retreat featuring warm-colored marble, wooden floors, and yacht-inspired aesthetics. The fluted geometry of the facade extends into floor treatments and lavatories, ensuring a cohesive design throughout the building.
This architectural triumph was made possible through an innovative procurement approach. A pre-validated glass specification was shared with multiple fabricators, enabling the owner, Tishman Speyer Properties, to pre-purchase high-quality glass at a negotiated cost. This process ensured optical precision, technical viability, and cost control, allowing the creation of a highly customized curtain wall within budget constraints.
The project has garnered acclaim, receiving awards such as the American Institute of Architects New York (AIA NY) Honor Award in 2023, the Council on Tall Buildings and Urban Habitat (CBTUH) Award of Excellence in 2023, and the Mies Crown Hall Americas Prize (MCHAP) Outstanding Projects award in 2022.
I’d like to know more about this mullion less glass system. In the 1970’s Heery & Herry did a type of mullion less glass curtainwall for the Georgia Power Headquarters Building in Atlanta. There were aluminum mullions behind the glass panels on all edges, but from the outside, no mullions could be seen. The glass was held in place to the mullions by an adhesive sealant. However, the state fire marshal was concerned that in the case of a fire, aging of the adhesive sealant, very high winds, or negative wind pressure on the glass panels, these glass panels could pop out. The popping out of the large glass curtain wall panels would be similar to the problem Pei Architects had the glass curtainwall company had with the glass curtainwall at the John Hancock Building in Boston.
Due to the fire marshal’s concerns, exposed clips were placed at the mid-points of each glass panel to provide a physical connection for each glass curtainwall panel. These exposed clips held each glass panel to each other and to the hidden mullion system that was located on the interior side of the curtain wall.
How has the problem of fire and positive/negative pressure been addressed with this mullion less glass curtainwall design? What do the deals of the curtain wall attachments to the structure look like? What were the design pressures on the glass surfaces? How is the issue of fire on any floor which might leap from one floor to another floor addressed??
How do you deal with expansion and contraction issues and possible separation of glass from each floor?
From the detail shown it is NOT a mullionless system. False advertising!
Why is this a good thing? The energy waste is enormous. The IECC requires 30% vision glass, not 90%, so the calculations must use a loophole that allows “high performance” glass to trade off U area. But we all know that full height glass gets cold, hot, makes for glare, can be unlivable and certainly requires more HVAC over the long term. I am sorry to see this direction in full glass continuing in the US. Thanks for the article, although it is fairly self-promotional.
How is this mullion-less? Clearly, there is metal framing at all glass assembly edges : i.e. mullions. I was expecting silicone adhesive only vertical joints with framing at head and sill only. Construction Specifier, you need to get better informed press release/ technical writers
Certainly an interesting design element, that is true. With that said, the article as a whole is like getting a meal of dessert without your entree or side dishes. It is self-promotion to Sherman’s point. I would share Sherman’s point in that there are significant concerns over the efficiency of the curtainwall as a whole, but since when does anyone in Washington DC actually care about costs and efficiencies? DC is kind of like Disneyland, more about fantasy and appearances than practicality. In the end it is still a curtainwall with mullion support, just strategically hidden from the “traditional” public eye.