The Prudential Plaza and 888 Boylston sustainable mixed-use tower are the most recent addition to Boston’s landmark Prudential Center complex. LEED Platinum certified and credited as one of the most sustainable office buildings in New England, 888 Boylston features a series of green roofs, rain gardens, wind turbines, and solar panels that help to both power and irrigate the plaza. Running through the heart of Boston’s Back Bay Neighborhood, Boylston Street is one of the city’s major commercial arteries which attracts daily crowds of residents and tourists and hosts city-wide events, including the Boston Marathon finish line. The existing site was comprised of a series of stepped, open plazas that didn’t protect pedestrians from the wind and wasn’t effectively utilized by the public.
The project began with an intensive wind study which showed that the most intense forces occur at the edges of the property, inspiring the plaza’s design. A complex gradient paving pattern, sculptural “wind swept” granite planters, and a grove of stainless steel light masts and wind vanes that, together, complete a conceptual vision of material innovation in the plaza that highlights the phenomena of wind on the site. The plaza has strict weight limitations, which created unique challenges in the design of the monolithic stone planters. The latest 5-axis CNC technology was employed to allow the planters to be intricately carved and adjusted to meet the restrictions. The undulating granite planters are sculpted into light, sweeping figures that emerge from the ground and transform into sculptural planter walls, seating, and signage opportunities. The planters are positioned along the urban sidewalk and define a porous threshold along the streetscape to frame a central plaza.
The raised planter walls retain a grove of Ginkgo trees and woodland groundcover that provide a green screen between the busy streetscape and the central plaza. This densely planted grove provides wind mitigation for pedestrians within the central gathering space. Tall, slender, stainless steel light columns with wind vanes, standing nearly fifteen feet tall, are also positioned within the planters.
The planters are aligned with the paving bands to create a seamless transition between planter and walkable surface. A field of gradating pavers infills the space between the dark directional bands, radiating to building entrances and merging into the city sidewalk to guide circulation. The overall gradient of the plaza pavers starts at the building face and lightens as it extends to the streetscape.
Each of the 44 light columns are custom fabricated using a single metal strand that wraps around structural rods to create a delicate spiral translucent screen that is densely wound at the base and gradually opens towards the sky. A series of mockups were built over a period of two years to study the height and design of the custom columns and wind vanes.
At night, these beams of color-changing light are reflected off the mirrored wind vanes to create playful patterns of light across the ground plane. The design is connected back to the sustainable strategies defined in the building design, as similar color changing lights are used to illuminate the wind turbines on top the 888 Boylston tower. An anemometer on the tower roof provides wind velocity data to all of the LED light fixtures mounted within each light column. It signals the light fixtures to change color according to the intensity of the wind in a gradient defined by NOAA wind data;
– Cool Blue hues from 1.5 to 2.0 meters per second
– Emerald Green hues from 2.5 to 4.0 meters per second
– Gold hues from 4.0 to 5.0 meter per second
– Red and Magenta hues from 5.5 to 7.0 meters per second
The wind vanes, sculpted to rotate in the wind, work together with the LED lights to transform the plaza into a living wind map. Visitors interact with this colorful wind diagram and track the velocity of the wind through the beacons of light. The light shafts project upward to illuminate the wind vane’s mirror-finish base that caps each light column and projects a play of light on the ground plane. These reflective lighting poles assist in wayfinding, ensuring 24-hour lighting to the highly trafficked entrance, and offer unique placemaking potential by engaging with visitors with color, movement, and local weather information.
Through vibrant programming, this plaza has quickly become an icon for the Back Bay commercial district. The Prudential Plaza has enhanced the streetscape of Boylston Street with colorful light masts that provide visual interests for visitors passing by, sculptural planter walls that provide copious seating opportunities, and lush planting that both provides shade and softens this urban landscape. Once an underutilized stepped plaza, the new Prudential Center Plaza has improved access to adjacent office, retail, and dining establishments and has become a public epicenter of community gathering and civic activity.
The Prudential Plaza at 888 Boylston Street
Entrant office name: Mikyoung Kim Design
Role of the entrant in the project: Landscape Architect
Other designers involved in the design of landscape: N/A
Project location (Street, City, Country): 888 Boylston Street, Boston, MA 02116, USA
Design year: 2013
Year Built: 2016