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‘Dorchester Bay City’ would bring housing, shops, and offices to the former Bayside Expo Center site. Here’s what to know.

New Developments News Dorchester
A rendering of what Dorchester Bay City could look like, as currently proposed.
A rendering of what Dorchester Bay City would look like, as currently proposed. Accordia Properties LLC via BPDA

More than a decade after Bayside Expo Center shut its doors, a developer has put forth plans with the potential to create a nearly 6 million-square-foot hub of housing, retail, and office space at the Columbia Point site.

Accordia Partners LLC recently submitted the proposal for the development, dubbed  “Dorchester Bay City,” to the Boston Planning & Development Agency, which envisions a sprawling 33-acre complex across the Bayside property at 200 Mt. Vernon St. and the adjacent 2 Morrissey Boulevard parcel.

Accordia, in a project notification form, wrote the endeavor “will be transformative for the Columbia Point peninsula and surrounding neighborhoods by creating a new destination that enhances the existing institutions on Columbia Point and generates thousands of construction and permanent jobs.

“By providing wonderful new public spaces with improved access to the Harborwalk, retail and open space programming available to all, and a mix of uses that ensures a 24/7 community that embodies live, work, and play, the Project will become a dynamic hub for all Bostonians,” the proposal says.

The build-out could take 10 to 15 years to complete.

The filing was made after Accordia, and its financing partner, Ares Management Corp., inked a 99-year, $235 million lease last year with the University of Massachusetts Boston, which purchased the Bayside site in 2010.

At the time, UMass Boston said the deal provided the school with the cash needed to fix up a crumbling campus parking garage and could help support a new nursing school facility.

Accordia and Ares picked up the Morrissey Boulevard site in 2019 for $110 million.

Here are a few key aspects of the plan:

The proposal calls for 1,740 units, with some affordable housing as mandated by city policy.

A rendering of Dorchester Bay City. —Accordia Properties LLC via BPDA

Accordia is seeking to split a mix of housing units across the two sites, with 1,455 of them at the Bayside property and 285 off of Morrissey Boulevard.

Plans call for a consideration of “a variety of residential options and rent levels” to meet goals set by the Columbia Point Master Plan, which seeks housing for residents across income levels.

Developers are exploring the potential to build units in line with the city’s “Compact Living Pilot” program as well as co-living units, “a concept where bedrooms and bathrooms are rented by individuals and common living spaces are shared,” the proposal says.

“A range of unit sizes to be created at the Project — from micro-units to standard studios, one-, two-, and three-bedrooms — will also diversify the market rate offerings,” the filing says.

Plans also outline an intent to include affordable units within each residential building, and will be built under the requirements of the city’s Inclusionary Development Policy, which mandates that at least 13 percent of a development’s units be deemed affordable. Those units will be available to households earning 70 percent or less of the Area Median Income.

“The Proponent’s goal is to create a mix of affordable housing, workforce housing and market rate housing that will attract households of many different sizes and income levels who want to live in a well-planned, transit-oriented, amenity-rich, mixed-use waterfront development,” the proposal says.

Additionally, across the complex’s 17 total buildings, the proposal eyes creating 155,000 square feet of retail and restaurant space, along with more than 4 million square feet of office and research space, potentially for use in the life-sciences sector and academia. Building heights would vary, with the tallest capping out at 294  feet.

The project would house on-site parking for 2,650 vehicles; however, new roadways would provide for pedestrian access and would come complete with bicycling infrastructure as part of an initiative to encourage alternative transportation.

The site is currently vulnerable to flooding. Plans seek to put in protections.

“The likelihood of the Project Site being flooded in the near- (by 2030), medium- (by 2050), and long-term (2070) time horizon is increasing, as storm events have been increasing in magnitude and frequency due to warming temperatures,” the project proposal says.

To combat rising sea levels, Accordia plans to put in place several flood protection and mitigation features, including by elevating the site and an “ecological barrier that is subtle in its visual impact, but effective.”

“Design strategies may include adapting to sea level rise through measures such as incorporating hard and soft barriers and wave breaks (through the landscape design), stormwater systems, and hardened utility systems,” the filing says.

Developers say their strategy will work in step with other climate-resiliency efforts in the area.

“North of the Bayside Site, the City’s Moakley Park feasibility study addresses resilience strategies for the area north of the Bayside Site, and includes a discussion of the installation of a berm (or flood management alignment strategy) to provide a flood barrier and protect the neighborhood from flooding during coastal storm events in the future,” the proposal notes. “The exact height, location, and materials of the proposed berm are part of the ongoing Moakley Park feasibility study.”

The development would link to the state’s Dorchester Shores Reservation and would create 20 acres of open space.

Accordia Properties LLC via BPDA

Accordia plans to create 20 acres of open space throughout the complex.

Dubbed “The Boardwalk,” the “central spine” of the Bayside site development will be a green promenade that connects an entry plaza on Mt. Vernon Street to the state-owned Dorchester Shores Reservation.

“Parallel to the central Boardwalk, to its north and south, will be linear open spaces to host neighborhood scale gatherings and a variety of day-to-day activities,” the filing says, referencing two areas presented as “the Neighborhood Corridor” and “the Portal.” “These more intimate public corridors will link together a host of community courtyards and green spaces.”

A deck between the development and the reservation — nicknamed “The Porch” — will offer views of the Boston skyline, Moakley Park, Carson Beach, and Dorchester Bay.

“The Porch will be a series of spaces that extend the public offering towards Dorchester Shores Reservation,” the proposal says. “They are the Porch Decks, the Promenade, and the Garden Terrace. Each will be a distinct public space that provides programming along the water’s edge and integrates the Project Site character with Harborwalk and Harbor Point.”

A fourth corridor, “the Draw,” would straddle the line between Dorchester Bay City and the adjacent Harbor Point Apartments to the southeast. Features include a bike path, and “layered plantings will weave through shared gathering spaces and amenities,” the filing says.

The BPDA is accepting comments on the proposal through Nov. 9. The project’s Community Advisory Committee is slated to meet Wednesday evening.

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