Congress Square, Boston, Massachusetts.
| Owner: | Related Beal, Boston |
| Architect: | Arrowstreet, Inc., Boston |
| Vitro Architectural Glass Products: |
Solarban® 60 Starphire® Glass |
| Vitro Certified™ Fabricator: | Oldcastle BuildingEnvelope®, Wright City, Missouri |
| Glazing Contractor: |
Cheviot Corp, Needham Heights, Massachusetts |
| Curtain Wall Contractor and Fabricator: |
Kreysler and Associates: American Canyon, California, and Midwest Curtainwalls, Bedford, Ohio. |
As part of a larger initiative to reinvigorate downtown Boston, Arrowstreet, a local architectural firm, was tasked with redesigning a block of 1900s-era bank buildings in the city’s Congress Square district. In a creative blending of old and new, the architects designed a seven-story jewel box with a trendy soffit that sits atop two adjoining Class B office buildings.
To successfully execute its bold design, Arrowstreet needed a lightweight material to contrast the original granite and limestone building facades with the new curtainwall addition. Their solution was Solarban® 60 Starphire® glass from Vitro Architectural Glass.
“We felt strongly the materiality and massing of the new addition needed to be distinct from the existing buildings to preserve their original character,” explained Jason King, AIA, LEED® AP BD+C, senior associate, Arrowstreet. “The custom unitized curtainwall system incorporates ultra-transparent Solarban® 60 Starphire® glass, providing both striking views into and out of the building and allowing the addition to feel lighter above the weightier masonry building below.”
To integrate the 24-foot cantilevered glass box, the design bends inward along Congress Street, adjacent to Post Office Square, at the exact point where the 1904 and 1906 building façades connect below. The faceted, angular design then extends downward through the existing building on the north façade, forming the building’s second entry point and connecting it to the popular boutiques and cafés located along Quaker Lane.
“While coordinating these faceted curtainwall panels with the existing structure was challenging, the result is a wonderful moment where the juxtaposition of old and new is no longer experienced from afar,” King added.
Another key aspect of Arrowstreet’s melding of modern curtainwall with century-old masonry is a custom-designed fiberglass reinforced plastic (FRP) soffit with a gold finish. The soffit’s unique depth and texture enables the glass to float gracefully above and complement the existing cornice line.
The renovation and addition also feature exterior roof decks on levels five, 10 and 17, providing beautiful garden-like spaces where tenants can work, meet and take breaks while enjoying fresh air and majestic views of Beantown.
While indoors, employees also are afforded striking city views through the low-e-coated Starphire Ultra-Clear® glass, which is 87% less green than ordinary clear glass. When coated with Solarban® 60 solar control, low-e coating, Vitro Glass’s premier low-iron glass delivers visible light transmittance of 74%, while blocking 59% of solar heat gain.
To arrive at the ideal glazing selection, Arrowstreet tapped into the Vitro Concierge Program™ for assistance with glass selection and specification and technical and logistical support.
“There were numerous challenges associated with erecting a new seven-story structure above an existing 1900s era building in a dense, urban environment like downtown Boston,” explained King.
Working from a tower crane to build the steel superstructure and pour the concrete floors, the glazing installers hung each unitized panel from the interior using a spider crane.
In addition to the glass box, Solarban® 60 Starphire® glass was installed in two-story curtainwall sections adjacent to the buildings’ historical main entrance on Water Street.
Because the original street-level windows were dark and faced with decorative metal grillwork, the beautifully crafted details of the interior lobby were hidden from public view. “By introducing Starphire® glass at the ground level, we were able to showcase those historical elements and re-brand the building from dark and uninviting to bright and welcoming,” King said.
Experts from the Vitro Concierge Program™ coordinated with fabricators at Oldcastle BuildingEnvelope to optimize glass sizes and shapes for the jewel box to achieve its angular, faceted design.
The building team also renovated and consolidated the elevator core, which consisted of three sets of elevators, restrooms and stairwells from three separate buildings. “Adding to this inefficiency was an existing lightwell in the center of the building, which brought little light to the interior spaces due to the much taller surrounding buildings,” King explained.
With the incorporation of a new central core within the footprint of the lightwell, the building owner was able to reclaim the old elevators, restrooms and stairwells as usable square feet. In replacing the lightwell with Solarban® 60 Starphire® glass, the lobby was transformed into a bright, daylit, energy efficient space.
To learn more about Solarban® 60 Starphire® glass and the rest of Vitro Glass’s full line of architectural glasses, visit www.vitroglazings.com or call 1-855-VTRO-GLS (887-6457).
