Case Study

Conrad Washington, DC

Guardian SunGuard AG 43 coating on UltraClear low-iron glass on Conrad Washington, DC

The Conrad Washington, DC luxury hotel is part of City Center DC, a mixed-use, public-private development plan designed by Herzog & de Meuron.

At the hotel’s ground level, ribbons of curved storefront glass wrap a band of retail spaces to engage and activate the public sidewalk while reinforcing the street front. The convex shape of the glass also engages with the scale of the pedestrian, while the upper floor facades react directly to the internal hotel functions and the larger urban context while emphasizing the monolithic aspect of the overall massing.

  • Washington, D.C. Location
  • Hotel Building Type

“The design is very unique; it’s very progressive,” says Javier Sánchez-Gil, Chief Operating Officer for Cristacurva, an independent Guardian select fabricator.

During the glass selection process, independent Glazier Connection Member TSI Corporations recommended Cristacurva. The Herzog & de Meuron team wanted a reflective, neutral glazing product to compliment the first-floor curved glass, and continue on to the flat glass of the upper floor facades, which react directly to the internal hotel functions and the larger urban context while emphasizing the monolithic aspect of the overall massing.

“Because it is a hotel, daylighting, aesthetics and reflection were the most critical components in the glass selection,” explains Peter Cornellier, TSI President. “The aesthetic had to present consistently for both the curved and flat glass. And reflection was particularly important to make sure a person’s appearance in the curved glass did not portray a ‘funhouse effect’. We created a visual mockup of the insulating glass unit to display the exterior and interior perspective – including a hotel room mockup, too – so the design team could analyze the appearance of a person’s reflection at different times of day under different lighting.”

Cornellier adds that Cristacurva’s product knowledge and technical support was central to the glass selection process.

“We expressed to the project team if you want high performance reflective glazing, when it comes to curved glass, you should choose a Guardian product,” Sánchez-Gil says. “Cristacurva presented many samples, fabricated different mockup compositions, and provided locations of Guardian SunGuard building applications so that the design team could see similar products. As a result, Guardian SunGuard AG 43 coating on UltraClear low-iron glass was specified.”

Guardian SunGuard® AG 43 coating on UltraClear™ low-iron glass creates a dynamic exterior further punctuated by the Conrad’s curved, first-floor glass. This aesthetic is complimented by its energy performance: On low-iron glass, the product provides a visible light transmission of 45 percent with a solar heat gain coefficient of 0.33. The visible light outside reflectance is 30 percent, while the visible light inside reflectance is 15 percent.

“Guardian UltraClear low-iron glass adds to the artistry of the Conrad’s façade because the low iron content of the substrate reduces the natural green tint,” explains Bruce Milley, Architectural Design Manager, Guardian Glass Americas. “It maximizes light and renders colors, textures and images with impressive fidelity. Combined with the dramatic curved profile, the result is a unique, dramatic building.”

Cristacurva fabricated approximately 15,000 square feet of curved insulating glass units for the structure’s first floor. The upper floors utilized roughly 11,000 square feet of curved IGUs for angles and corners (further complicated because each corner is a slightly different size) and approximately 100,000 square feet of flat IGUs. TSI installed all of these glass make-ups.

Cornellier says Guardian Glass further differentiated itself and its product from competitors with assistance to the design team mapping out the curve requirements, and with its warranty offering.

“We feel comfortable with SunGuard products because Guardian has always been very supportive in the use of their coatings for curved glass applications,” Sánchez-Gil adds. “This in turn has allowed Cristacurva to be very successful in providing high performance glass solutions with outstanding curved glass quality.”