After years of planning and discussion, the massive Assembly Row complex in Somerville has entered a new phase as developers started construction Wednesday on the first two buildings of the $1.5 billion project.
The apartment buildings by AvalonBay Communities Inc. will have 448 rental units, and at 470,000 square feet is one of the largest residential real estate projects under construction in the Boston area, according to the developers. One of the two buildings will be an “AVA’’ residence - AvalonBay’s newest apartment brand that was introduced nationally last year.
Bill McLaughlin, executive vice president of development and construction at AvalonBay, said each apartment building will be targeted to a slightly different demographic. The Avalon at Assembly Row, with 195 units, will be a more traditional apartment complex. The second, AVA Somerville, will have 253 apartments in a more contemporary design, and feature smaller units aimed at younger residents. Many of the AVA units will be engineered for roommate living.
“Each building will have its own distinctive flavor,’’ McLaughlin said.
The project will create a mixed-use neighborhood of offices, stores, restaurants, homes, a hotel, and new MBTA station. Its developer, Federal Realty Investment Trust, recently said it plans to include dozens of outlet stores among the retail offerings at the 45-acre complex.
Federal Realty is also refurbishing the park at the rear of the property along the Mystic River.
Conceived in the late 1990s, Assembly Row has suffered through several delays, at first due to community opposition to an earlier version and then because the economic downturn dried up funding for large-scale commercial developments.
But last fall the project received $104 million in US and state funds, coordinated by the Patrick administration for an access road and other site preparation work and money for the MBTA station. Somerville also provided $25 million in bonds to pay for road and utility upgrades.
Federal Realty also redeveloped the adjacent Assembly Square Marketplace, which includes a Bed Bath & Beyond, Sports Authority, Christmas Tree Shops, and other big-box retailers. The two projects combined will sprawl over 69 acres.
The construction of Avalon at Assembly Row and AVA Somerville is expected to be completed in July 2014, with occupancy to begin in the summer of 2013.
More information: Assembly Row
Size: 45 acres
2,050 housing units, 200-room hotel
1.75 million square feet of office space
830,000 square feet of retail space, including Ikea and a 12-screen movie theatre
MBTA Orange Line station
Total cost: $1.5 billion