Architectural preservation is often cast as a zero-sum game; historic structures are either painstakingly maintained or demolished in favor of contemporary development. Arrowstreet's Congress Square, a 530,000-square-foot project in Boston's Financial District, provides an alternative solution for this quandary with the restoration and consolidation of an entire block of historic structures that integrates a contemporary glass addition with a fiberglass reinforced plastic (FRP) soffit.
The historic core of the project is composed of three separate Beaux-Arts banks built in the early 20th century. Over the course of their lifetime, and a number of financial mergers, the banks were haphazardly joined into a single entity. A lightwell was located between these three structures but it was filled with a web of mechanical systems over the years.
Island Exterior Fabricators
InstallerThe Cheviot Corporation
Consigli (General Contractor)
Related Beal (Executive Construction Manager)
Custom-designed unitized curtain wall
ProductsCustom glass and FRP modules
For the design team, one of the greatest challenges of the project was how to structurally support the seven-story glass addition, and its 24-foot cantilever, without visually disrupting historic elements. "A 1,700-square-foot mat foundation was constructed in the basement supported by more than 60 mini-piles that were all driven inside the existing building," said Arrowstreet President Amy Korté. "Fourteen super columns were then threaded through the perimeter of the existing buildings to support the vertical addition."
Additionally, a new concrete core was inserted within the lightwell to both support the new glass canopy as well as house contemporary mechanical equipment. The new concrete core also facilitated the open-floor plan of the glass-clad office space.
The structure's sharply-angled cantilever and soffit are located on the prominent southwestern corner of the project, adjacent to Post Office Square. Arrowstreet collaborated closely with the FRP and the curtainwall manufacturers, Kreysler and Associates and Midwest Curtainwalls, to develop the soffit design. The design and fabrication teams reviewed three color options in both glossy and matte finishes, constructing full-scale mockups to effectively gauge the product most complementary with the historic ornamental metalwork found throughout the buildings. Ultimately, the team settled on an iridescent gold-like finish that reflects light to the street below.
"Our team refined the design of the soffit using Rhino 3D software and 3D printing to visualize the final installation," continued Korté. "Sharing these models, we could interface directly with Kreysler and Associates' sophisticated fabrication equipment, including six-axis CNC robotic routers to realize complex geometries."
While the bulk of the project focused on the insertion of the seven-story glass pavilion atop three historic banks, the northern rump of the mixed-use project involved the restoration of two additional historic structures and the construction of an entirely new 12-story addition. The facade of the addition was manufactured by Island Exterior Fabricators and was fully installed in under two weeks.
Amy Korté, Arrowstreet President, will be presenting a deeper dive into this project as part of the panel, "Lightness & Weight | Creating Continuity in Cityscape with Hybrid Facades" at the upcoming Facades+ conference in Boston on June 25. For more details, along with registration info, visit Facades+ Boston.
On June 25, Facades+ is returning to Boston for the fourth year in a row. The conference, organized by The Architect's Newspaper, is a full-day event split between a morning symposium and an afternoon of workshops led by top AEC practitioners. Leers Weinzapfel Associates (LWA), a Boston-based firm with projects nationwide, is co-chairing the conference.
Panels for the conference will focus on the changes underway in Boston, ranging from new educational structures, the city's new tallest residential building, and historic preservation projects.
Participants for the conference's symposium and workshops include Behnisch Architekten, Knippers Helbig Advanced Engineering, Pei Cobb Freed & Partners, Bruner / Cott, Arrowstreet, Consigli Construction, Walter P. Moore, Autodesk, Atelier Ten, Harvard GSD, the Wyss Institute, and Okalux.
In this interview with The Architect's Newspaper, LWA's designer and business development representative Zhanina Boyadzhieva and associate Kevin Bell, the conference co-chairs, discuss their firm's growing body of work and the developmental trends within the city of Boston.
The Architect's Newspaper: Boston is known as a relatively quiet city with a predominantly low-slung skyline. How is current development reshaping that identity and what does it mean for the future?Zhanina Boyadzhieva: Boston is indeed a “quiet” city, but it is also a hub of innovation and creative thinking. In the past few years, we have observed dynamic design work, largely by local firms, on several fronts: 1) creative re-envisioning of historical landmarks through readaptations and additions such as Smith Center at Harvard University and Congress Square in downtown Boston 2) careful insertions of new landmarks in the skyline such as One Dalton 3) fast development and growth of existing or new resilient neighborhoods such as Harvard’s Allston campus. Each design solution addresses unique urban conditions and entails holistic thinking about city planning, resilience, and sustainability, coupled with a sense of function, form, materiality, and human experience.
Naturally, facades combine all of these considerations and become dominant players in the reshaping of cities. The diversity of approaches we observe—controlled material juxtapositions of old and new, sculptural form-making, and playful screening strategies—are testaments to ongoing design experimentations here. There is a search for new methods to address creative reuse, high performance, material fabrication, and user experience.AN: The city possesses one of America's largest concentrations of brutalist buildings, as well as large historic districts. How can Boston embrace its heritage while moving forward?Kevin Bell: The rich building history of Boston, including modern landmarks like City Hall, and its brutalist companions make for wonderful urban fabric for intervention and a great place for an architect to practice. This history should serve to elevate our expectations for new buildings and major renovations in the city. The recent warming to Boston’s brutalism, its strong geometry and bare materials, is welcome, encouraging designers to consider rather ignore these local icons.
It presents the opportunity to consider adaptation and re-envisioning through sustainability’s lenses, the human experience, and materiality. If we can dramatically improve the energy efficiency and human use in these sensitive historic buildings, we can achieve the same in new construction and create a model for continued improvement.
AN: What innovative enclosure practices is LWA currently executing?KB: As a firm, we have a legacy of designing efficiently in an urban context. Often, our site is an existing historic building or a tightly constrained sliver of land, or sometimes, there's no site at all. This fosters a sensibility within the studio toward compact volumes, materially efficient, with taut fitted skins, a practice that serves us well as we work to make evermore energy efficient and sustainable buildings. We're also redefining our performance expectations around our clients' commitments to energy efficiency, many of whom have established operational carbon neutrality as their aim by mid-century. The enclosures we design today will be part of that efficiency equation. They must be considered to be part of a carbon neutral organizational environment as a performance baseline above simple compliance with today's codes or target certifications. Envelope performance, especially the use of innovative glazing materials, is a logical extension of the way we think about reactive, efficient space and energy efficiency targets in building enclosure design.
Our Dartmouth Dana Hall renovation and addition, under construction now, is an example of this process and practice. We worked closely with the college to define a program for building reuse around its energy use reduction targets that dramatically improved envelope efficiency. Through the design process, we worked with our design and construction partners to continually refine the design while holding to incremental improvement in energy efficiency at each step; our modeled efficiency improved even as we moved through cost reduction exercises. The result is a highly insulated building, triple glazed throughout, with a thermally improved, south-facing glass curtainwall system combining vacuum insulated high-performance glass modules with integrally solar shaded, triple glazed vision glass as part of a building with a predicted energy use index (pEUI) in the middle twenties before the introduction of site renewables.
AN: Which materials do you believe are reshaping facade practices?ZB: Materials are the agents of larger design strategies shaping the practice such as resilience, sustainability, and human experience. The aim to rethink and cherish historical buildings, for example, leads to a careful layering of existing and new materials that contrast and simultaneously enhance each other. Heavy textured concrete at the Smith Center is supplemented by light and open transparent glass, green walls and warm wood. Traditional brick block at Congress Square is juxtaposed with a floating glass box on top of sculptural fiber-reinforced plastic panels.
On the other hand, the vision to create new landmarks that celebrate and reshape the Boston skyline result in the careful sculpting of distinctive volumes as in One Dalton, a tall glass skyscraper with careful incisions of exterior carved spaces for human use. Finally, the goal to produce energy efficient but playful envelopes leads to a game of patterns composed of an inner insulated layer with an outer wrapper of perforated metal screens or angled aluminum fins. Each choice of material and its manipulation reflects a larger vision to create a unique experience in the city.
Further information regarding Facades+ Boston can be found here.
The Massachusetts Port Authority (Massport) has big plans for Boston's Logan International Airport, ranging from the modernization of Terminal E to the expansion of adjacent runways. In 2016, as part of these modernization efforts, Boston-firm Arrowstreet delivered a dynamic expansion of its West Garage featuring a kinetic aluminum facade.
ManufacturerEXTECH Exterior Technologies, Inc.
InstallerIpswich Bay Glass Co.
SystemCustom kinetic skin designed, prototyped, and tested by Arrowstreet and EXTECH
ProductsCustom-fabricated KINETICWALL Dynamic Facade by EXTECH
Located adjacent to the I-90 and the Logan Airport 9/11 Memorial, the site is highly visible to the nearly 30 million passengers that pass through the airport annually. The objective of the project? To deliver an easily assembled second skin capable of obscuring the structure’s utilitarian purposes while simultaneously providing outward views from within. According to Arrowstreet Principal David Bois: “The movement of air currents, a critical component of aviation, provided inspiration to the design team, the individual movement of the panels provides a visualization of air movement and a constantly changing facade.”
Faced with a tight schedule, Arrowstreet recognized that the screen wall had to be fastened to the garage in a straightforward and adaptable fashion. The facade system is composed of 353, 11-by-5-foot panels that are Z-clipped to individual galvanized hangars, which are epoxy bolted to the precast concrete garage. Because of the Z-clips, individual panels can be rapidly removed from the overall structure for ongoing maintenance and inspection.
The kinetic element is composed of six-inch curved aluminum squares that can move in the breeze. The 50,000 individual flappers are connected to the frame by a series of stainless steel rods and nylon spacers that allow the flappers to spin with the least amount of friction possible. With minimal resistance, the panels move even during minimal wind conditions.
Below the moving aluminum flaps, Arrowstreet placed tiered rows of multicolored fins to provide the structure further luster.
The design concept was modeled in Rhino and Revit, and the team was able to simulate the kinetic movements of the system for various panel sizes. After Arrowstreet tested a broad range of panel sizes, the firm exported the models for custom fabrication by exterior specialists, Extech. Linetec finished the flappers with their Class I clear anodize.
Prior to installation, Arrowstreet installed a full-scale mockup onsite to test installation procedure, functionality, and resiliency. Furthermore, a section of panels and flappers were transported to Intertek’s architectural testing facility to undergo hurricane simulations to evaluate the resiliency of the fabricated prototype during extreme weather conditions.
Boston is moving closer to turning an under-utilized part of its financial district into a 24-hour, mixed-used entertainment center. BostInno reported that the Boston Redevelopment Authority held a meeting on the project Monday night, which has been dubbed "Congress Square."
The plan, which is being pushed by local developer Related Beal and designed by Arrowstreet, would breathe new life into a sleepy cluster of buildings around Quaker Lane. "The Project will transform existing office buildings into three components with a mix of ground floor and lower level retail/restaurant uses with either office, residential or hotel uses on upper floors, providing appropriate 24-hour activity to the surrounding neighborhood," said Related Beal in its proposal. "The Project includes approximately 458,300 square feet, of which approximately 92,700 sf is new construction."
But the focus of the project, at least from an urbanist's point of view, is the new pedestrian passageway that replaces an existing alleyway. Adding to the people-friendly, placemaking spirit of the project, Congress Square includes new bike storage but no new parking spaces for cars. If everything goes according to plan, Related Beal plans to break ground this year and wrap things up in 2017.