There were plenty of tribulations associated with the design and construction of Archstone Avenir, a mixed-use development in Boston’s Bulfinch Triangle, and the toughest were underground.

First, the project was built atop land that was reclaimed after above-ground subway rails and highways were buried as part of Boston’s Big Dig. Second, it sits directly over the North Station Super Transit Station, so its foundation had to align perfectly with the tunnel’s walls. To dampen vibration and noise from the trains, the building sits on 8-inch neoprene pads, explains Janis Mamayek, a principal at ICON architecture who served as project manager.

The constraints above-grade were no small matter, either. The multistory structure, which covers an entire city block, had to blend in with the fabric of its historic neighborhood, which includes low-rises, as well as taller buildings and the TD Banknorth Garden Arena. To top it all off, construction was scheduled around the arena’s performances, Mamayek says, and had to be timed to allow the trains to run uninterrupted.

The resulting edifice, with 40,000 square feet of retail and 241 apartments, has 10-story sections on each end, with shorter volumes of three to five floors in the middle. The design team concealed the second- and third-floor parking garage from street view by wrapping it with two-story–high loft units that have floor-to-ceiling windows.

To cope with the deep footprint of the site, which might have made it difficult to provide enough daylighting for the apartments, the middle buildings are of varying heights and include roof terraces and decks for residents.

Learn more about markets featured in this article: Boston, MA.