Still, some architectural critics say the Seaport still looks more like an outpost of the suburbs or the Sun Belt than an extension of downtown Boston. And there’s only so much one building can do to change that, said George Thrush, an architecture professor at Northeastern University.

The problem, Thrush said, goes back to the original Seaport development plan, which called for wide streets and big lots suitable mainly for large buildings — albeit only up to 250 feet tall. Once that took hold, he said, the look and feel of the Seaport were almost preordained.

“It’s a completely alien pattern for Boston,” Thrush said. “But the pattern of the streets and the size of the streets defines the character of the place.”

The Boston Globe