Type Case Study
Topic Mixed-Use, Boston, High-Rise, Competition
Date Published October 12, 2017

Architecture and Building Form

The Great Hall – A New Urban Space for the 21st Century

The distinguishing characteristics of great cities are the civicscaled spaces that become iconic over time, retaining their essential grandeur and are capable of renewing over time with every new generation. They may be plazas, cathedrals or train stations. They may also be grand rooms, of such shape or quality that they remain lodged in our memories: The Galleria in Milan, the Grand Palais in Paris, or closer to home, the Reading Room of the Boston Public Library, Faneuil Hall, or Trinity Church in Copley Square. They become integral to the image of a city.

The most significant public feature of our proposal is The Great Hall: a distinctive gathering place active through all seasons and
a focal point for activity from morning into the evening. It is a new urban room of shape and size, intended to be inherently
civic in scale and function. It is a public connector, a celebratory arcade conceived as a signature space finished with warm stone
paving, shimmering metal panels and transparent glazing. These elemental materials are intended to convey simplicity and a robust permanence, adaptable to different activities inside. At either end, as The Great Hall opens to Winthrop Square or Federal Street, 20-foot tall glass panels open expansively in warm months to the sidewalks, enhancing the continuity of the public realm. Flanking either side of the space are three levels of dining, cafe, and market activity. Similar to great streets, the markets, cafes, restaurants, office lobby, and other programs open directly onto and flank the main spine of the space, further energizing the pedestrian realm. Opposite the office entrance is a 50-foot “green wall” of vertical plantings, bringing a significant presence of natural vegetation into the space.

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The High Rise Skyline

The distinguishing features of Boston’s high-rise skyline have remained relatively unchanged over the past 30 years. At the western end, the truncated “High Spine” of the Back Bay has been dominated by the Prudential and Hancock Buildings, recognizable fixtures on the skyline. Downtown, the Financial District has been dominated by relatively blocky and undistinguished office buildings, clustered from Beacon Hill to the waterfront. This has begun to change with several impressive projects under construction, and in particular with the completion of Millennium Tower, whose dramatic form pinpoints Downtown Crossing.

115 Winthrop Square, a new shimmering prism situated in the Financial District of Boston, will give new definition and vitality to an important urban space. 750 feet tall, this building is a synthesis of form: a complex, angular podium base resolving into a taut, slender tower, carefully positioned in a neighborhood of bulkier office structures. The shape and form of this tower will create a new visual pinnacle in the heart of the Financial District and on the city skyline. It will be a new marker in the sky indicating the heart of the new 24-hour enhanced Financial District.

The architectural DNA of the heart of the Financial District around Winthrop and Post Office Square was firmly established in the early 20th century, with a cluster of distinguished Art Deco-era buildings. It is from this tradition of modernism– with an emphasis on vertical expression coupled with artful detailing–that we draw inspiration for a language of new high-rise expression on this downtown site, harnessed in the service of 21st century high-performance building technology.

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The Hybrid High-Rise

The fundamental characteristic of this project, and what has become a paradigm for successful urban revitalization in historic city centers, we define as a Hybrid High-Rise Residential Building. This is no ordinary mixed-use building. Like a hybrid plant, which is cross-bred with sturdier species to become more robust and often more complex in form, the hybrid building – with its complex and diverse functions – when artfully assembled, has the power to drive significant pedestrian activity on the street through mall hours of the day. The more public functions of The Great Hall (retail, restaurants, events) and the office spaces, when coupled with residents living in the building, will create a critical mass of activity on the streets and squares in this neighborhood.

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Building Form 

Elementally, the building is a traditional “tower on a podium.” The tower, composed of residential apartments, is lozenge-shaped and oriented along the north-south axis. The podium, containing retail, restaurants, and office space, is dramatically punctuated by a major public space linking Federal Street to Winthrop Square, forming The Great Hall. Straddling The Great Hall is a mid-rise wing of the “Office Solaria”: a set of interconnecting office convening spaces stacked within an articulated steel frame and bathed in light.


The high performance enclosure of the building is conceived as an articulated metal skin dissolving as it rises into a set of deeply etched glass planes, creating a lively, everchanging pleated surface of light, shadow and refractions. The metal is authentic: nickel silver panels that softly glow and warm to different hues depending on sun angle and weather. The composition of these materials is intended to complement the limestone, light masonry, and warm bronze detailing of the neighboring Art Deco buildings. The pleating motif is amplified at the Office Solaria wing with a serrated glass enclosure wrapping the volume. The edges of this transparent photovoltaic double glass wall system play off the dense angularity of the neighboring Paul Rudolph masterpiece at 133 Federal Street.


The Pleated Wall 

While the fundamental compositional strategy is a tower with podium, the tower, oriented to face east and west, results in a broad surface. Our strategy is then to “break up the box” by fracturing the surfaces. This creates a series of angular planes that wrap the tower and podium and refract the reflections of the sky on the surface, creating an intricate composition of refraction and reflection. It also increases the visual depth of the wall and enhances the presence of the warm metal colors reflected on the glass.

Not unlike the soft but angular folds of a pleated fabric skirt, the Pleated Wall serves a practical purpose too: bay window spaces
inside the office floors orient a large portion of the glazing to the northeast and northwest, thereby reducing the solar heat gain while providing ample natural light.


Several distinguished buildings in the immediate vicinity of Winthrop Square provide an inspiration for materiality and detail. These are exemplars of the Art Deco era, dating from the 1920’s to the 1940’s. Located directly across Federal Street from the site is the United Shoe Machinery Corporation Building (now 160 Federal St, 1928).

Other nearby examples include the New England Telephone Building (185 Franklin Street, 1947); The Second National Bank (75 Federal Street, 1929); and the John McCormack Federal Building, by Ralph Adams Cram (Post Office Square, 1932). 

Inspiration is not just derived from architectural precedent. Employing metal in our façade is both a practical building material (spandrel panels that augment the high performance goals of our exterior wall) but also recalls the 18th century metal work, decorative and practical, from noted Boston silversmiths.

Building Uses

Residential Mixed Use Hybrid High-Rise buildings are, as a rule, composed of an intense array of diverse functions. Our project stacks these uses in a vertical arrangement that locates these uses in their optimum location. The ground plane is where all these uses intersect. Flanking either side of The Great Hall are retail and restaurant uses on three levels. The office lobby is part of the public realm, accessed from The Great Hall. The residential lobby is located at the base of the tower at the north corner. Service and parking ramps are discretely situated at the north and south edges of the site. 

Upper levels of the podium contain the Accelerator, an organized business assistance program for entrepreneurs to help further establish Downtown Boston as a hub of innovation across industries and support functions, typical office floors and the interconnecting Office Solaria.

The mid-level mechanical equipment floor contains the HVAC and plumbing equipment for the podium office and retail spaces. This level also acts as the structural transfer floor for the high-rise sitting atop the podium. The residential amenity spaces (lounge, fitness room, etc.) open onto a planted roof terrace. The tower contains approximately 300 residential apartments ranging from 850 – 2,500 square feet plus penthouses, over 36 floors with several intervening mechanical transfer floors. Contained in a 25- foot high, multi-level stack at the top of the tower are mechanical equipment rooms, window washing equipment, and photovoltaic panel arrays.

Site Design, Pedestrian and Vehicular Circulation and Connectivity

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Downtown “tesserae”

The site is located in the epicenter of three significant districts of downtown Boston: the resurgent creative commercial node of Downtown Crossing to the west; the primary transit gateway of South Station; and the vital Financial District to the east. Our program’s new Great Hall, coupled with the creative Accelerator office space, will become a pedestrian attractor. In this way it is part of urban “tesserae” – or links – that reinforce and add multiple pathways between these major nodes of Downtown.

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Urban “tesori”

Boston is blessed with iconic outdoor urban spaces: The Common, Copley Square, and The Fenway, among others. Downtown, important intimately-scaled spaces constitute part of the special texture of the Colonial-era city: Post Office Square, the soon-to-be-rebuilt Shoppers Park, the plaza dedicated for the Irish Famine Memorial and, between these, Winthrop Square. These are part of the city’s urban “tesori” or “treasures.” These are the memorable outdoor urban rooms of this district. In the summer, these spaces are teeming with pedestrians, vendors, tourists, and workers on lunch break enjoying the sun and verdure.

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The District Street Pattern

Boston’s streets were established by cow paths, or so the story goes. In reality, the Colonial-era pattern was formed by geography: the circumferential pattern east of Beacon Hill traversing the grade around the hill, and the radial pathways connecting the intense commercial activity of the wharves to the upland merchant shops. A distinct pattern of east-west streets are bisected by Washington and Federal Streets, radiating from State Street southwards. Our proposal envisions new streetscape treatments creating a living street and incorporating the 100 Summer Street Plaza into this network of pedestrian links, connecting Summer Street, the open terrace at 133 Federal, and The Great Hall. In this way, The Great Hall becomes part of a larger pattern of midblock pedestrian open space links.

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Reconstituting Federal Street

The east side of the site along Federal Street poses a challenge: how to reconstitute the western street wall that has been missing
for more than 40 years? Combined with the “negative space” created by the Bank of America building along half the block on the east side, the shape and character of the Federal Street façade has the potential to create some spatial order in an otherwise unresolved block. Our proposal resolves this problem with a detached vertical building form that mediates the height between 150-foot 133 Federal, the 390-foot 101 Federal Street tower, and the 240-foot 75 Federal building at the north end of the block facing on Franklin Street. All the while, natural light is allowed into the existing office windows at 101 Federal. The resultant stepped massing completes the street wall while respecting the inherent morphology of the disparate buildings on the block.

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Framing Urban Space

The site is bracketed by two 400-foot towers along Devonshire. Our Tower, gracefully inflected on its west face, creates vertical continuity between 100 Summer and 101 Federal. These tower faces roughly trace the contour of Winthrop Square, thus marking on the city scale this special location.

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Completing the Urban Room of Winthrop Square

The Great Fire of 1872 remade much of this district. The straightening of several thoroughfares, the creation of Post Office Square, and the new Boston Herald Traveler newspaper building at Winthrop Square gave new shape and a Victorian-architectural veneer to the neighborhood. But the 20th century transformation of the Financial District has been at bestindifferent to cogent urban space-making. At Winthrop Square, while the granite One Winthrop Square building still axially organizes the plaza landscape, shear façades of the 400-foot office towers flank the east side with an uneasy counterpoint of 90-foot masonry loft buildings to the west. The office program in our project introduces an intermediate scale, gently bending to re-establish the Devonshire Street side of the Square, creating a setback for the tower, and giving definition to the stately One Winthrop Square Building. The inflection will draw the eye to the arched canopy threshold of The Great Hall. 

Streetscape and Landscaping Elements

New buildings of this scale require a careful balance of respecting and building connections to the existing context while reimagining how the pedestrian realm – notably the landscape and street “furniture” – can create a new and forward-looking environment. Key to enhancing the pedestrian experience in this location will be the repaving of parts of Winthrop Square, Federal Court, and Milton Place. Prioritizing the pedestrian over vehicles can be done successfully in Boston; witness Downtown Crossing at Summer Street or the new Shoppers Park plaza plan. Our inspiration for this tactic is the plazas and streets in the Netherlands called woonerf, or “shared street.” Vehicles move through the space slowly and purposefully in an environment clearly prioritizing pedestrians. This strategy lets the exterior space and landscape of Winthrop Square extend seamlessly into The Great Hall and, in similar fashion, the 100 Summer Street Plaza paving reaches northward into Federal Court. This simple paving strategy unifies the block, making the inner portions clearly a pedestrian realm that share in controlled fashion the vehicles moving through it. The alleys and plaza become versatile in use; pedestrian strolling and shopping during the day, outdoor restaurant and café seating in the morning or evening, and after-hours service access in the evening.

New planting is proposed in discrete but key locations, and the plaza tree beds are reshaped with new seating borders. The ground-level landscape will expand upon Boston’s Complete Street guidelines including clear pedestrian, greenscape and frontage zones, scaled in a manner to robustly knit the pedestrian realm together. Paving materials will be high quality yet also allow for comfortable universal access. Planting and permeable paving will be included in strategic locations. Outdoor seating and lighting will be consonant with the contemporary character of the new building, while transforming Winthrop Square into a 21st century plaza and retaining its “classical” 19th century roots.

Vehicular Access and Parking

With the site’s close proximity to public transportation, shared vehicular and biking options, and its central location, the project will need less parking relative to other projects of its size.

Over the last 15 years, we have seen our retail, residential and office users in this neighborhood reflect the trend in other urban areas of becoming less dependent upon private vehicles for their mobility needs. Further, with the growing diversity of building uses in the Downtown and Downtown Crossing core, many more trips are accomplished on foot. The Roche Bros. grocery store experience in our recently renovated Burnham Building is most indicative of this trend, as patrons are visiting the store more frequently and buying less at a time while exclusively walking, biking, or using public transportation. 

This development will require less private vehicular transportation through Transportation Demand Measures, including the promotion of public transportation, shared vehicle use, biking, walking and fostering a culture of reducing each person’s carbon footprint. The project will have as many bicycle parking spaces as the users require, plus showers for bike-to-work commuters. There will be spaces for shared car services. And with valet attendants onsite at all times, the garage will accommodate as many electric-powered vehicles as the users require, even as demand increases over time. There will be accommodations to increase bicycle parking in and around Winthrop Square, and the project will have its own bikes, locks and helmets for shared use among residents.

The overall project’s parking capacity will be approximately 550 vehicles and is closely linked to the building’s structural foundation requirements after taking into consideration the priorities of off-street loading, resiliency measures and the building’s structural elements. Here, based on the underground conditions, and to optimize the geotechnical and structural design, we propose four levels below grade to secure the building directly to bedrock.

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Primary access for residential parking will be from Devonshire Street with a drop-off internal to the site at the residential entrance on the northern edge of the property. After the occupant drop-off, vehicles will proceed down an internal ramp not visible from the street or sidewalks and into the garage. Vehicle delivery will be handled in the reverse order and any queuing will be inside the garage and the site. Visitor parking for residents will be accommodated at the residential drop-off and pickup area onsite.

Access for commercial parkers in the property and all loading will occur off of Federal Court using a separate ramp and with the loading functions occurring on level B1 and the parking spaces located on the lower levels. The commercial parking operations will be valet-assisted on each level and the garage will be outfitted with stackers.

Residential Parking Capacity

The garage will have residential parking for 300 vehicles for the expected 300 units of housing. It is expected that, similar to our experience at Millennium Tower, 20%  units will be purchased by residents without vehicles and 20% by residents who keep more than one vehicle onsite. Further, we expect the residential vehicles to be used less over time as our experience with our existing residential units indicates. Currently, in the three fully occupied residential condominiums that we developed in the area, an average of 230 of the 720 residential vehicles (32%) leave the garage on an average weekday. This is down by 12% since 2004, when 44% left in a smaller sample size.

Commercial Parking

Restricted parking for commercial users is anticipated to be 250 spaces and accessed from Federal Court in a shared onsite ramp with the truck loading dock similar to the layouts at our Ritz-Carlton and 10 St. James Avenue projects. We expect the vast majority of office users to use public transportation, walk, or bike to work, as is the case in our Burnham Building development.

Retail, Restaurant and Great Hall Parking

During weekday times, we expect users of the shopping, dining and Great Hall facilities to take public transportation, walk, bike or take a fee vehicle to the site. On evenings and weekends, we expect users may also drive to the site. In this case, we will work with Boston Transportation to designate a valet drop-off and pickup area on Federal Street, with the valets using the Federal Court access ramp to the garage.

Autonomous Vehicles and Reduced Parking Demand

As autonomous driving vehicles become more prevalent, the ramp from the residential drop-off and pickup area to the car parking areas below grade will be able to safely accommodate new technology even as it evolves. Finally, as the demand for parking declines over the coming decades, the subsequent Condominium boards will be permitted to convert portions of the below-grade garage areas to storage for occupants of the building. A comprehensive transportation analysis will be done as part of the Article 80 Environmental Review.

Sustainable Development and Green Building

The Hybrid High-Rise is an ideal model for incorporating high-performance, energy efficient, sustainable design features. In targeting a significant portion of the project to meet Passive House standards – which is the most rigorous protocol for energy use reduction in the world – our goal is to set a new bar for market-rate, commercial building sustainable design performance. Buildings have a 50-100+ year immediate and  long-term impact on the environment. The most important component to get right from the outset is a robust exterior envelope. Meeting LEED Platinum will address many of the other important environmental impacts like water usage, recycling and renewable materials, and building operating procedures. But setting a very high standard for low energy consumption will have the largest impact over time. It is anticipated that, if successful in meeting these standards, the energy use reduction compared to a comparable commercial office building will be approximately 50-70%. In addition to the “passive” high-performance exterior envelope, the various “active” systems are highlighted in the accompanying illustrations. 

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High Performance Envelope

To meet the high bar we are establishing for energy performance, especially in the office component of the project, the exterior envelope must meet rigorous standards for detailing and installation. Both solar heat gain and internal heat loss must be minimized while maximizing the reach of natural light into these deep floor plates. Our design envisions a robust, triple glazed window unit coupled with spandrel panel to obtain an average of R-30 on the exterior wall. East and west facing glass, where most heat gain can occur, is mitigated by deep exterior vertical shading fins. All connections between the exterior wall and the interior structure are thermally broken to minimize thermal bridging, and all panel joints gasketed and sealed to prevent air leakage. The perimeter chilled beams – an efficient system that locates the cooling medium at the location of possible heat gain – double as light shelves. These reflective surfaces bounce the sunlight off the ceiling deep into the office space, thereby lowering the daytime lighting demand.

Elements of a high-performance building envelope include:

1. Comprehensive Design

All factors that affect the energy use and physical comfort of the building must be analyzed. High performance starts with a deep understanding of the building site climate and a common sense approach (i.e. thoughtful building orientation) combined with digital modeling and intensive energy analysis.

2. Minimize Energy Transfer Through the Façade

This is achieved through a highly insulated, airtight, thermally-isolated building envelope with high performing windows, typically triple glazed. At the same time, ensuring ample natural light to reduce lighting loads requires right-sized window openings. Combined with a tall and reflective ceiling, perimeter light shelves can reflect significant daylight deep into the floor plate. Shading, with passive elements like vertical or horizontal fins, reduces the heat gain on the outside surface of the glass. Actively shading systems on daylight timers also regulates heat gain and glare.

3. Controlled Assembly

A building’s envelope is only as good as its weakest link. Assembling the façade in an off-site factory, usually in a unitized panel system, enhances quality control. This is especially important with regard to air and moisture barriers, where even a small leak can significantly impact the overall effectiveness of the envelope.

4. Human Wellbeing

The final test of high performance is conducted daily, by those who occupy the building. Natural lighting, well-tempered clear air, a great view, and physical comfort result in a healthy indoor environment.

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