This rendering envisions Waterstone Properties Group’s proposal for a mixed-use urban development called “Rock Row” on the 26-acre former Pike Industries quarry site in Westbrook. The developer said last year that Market Basket would anchor the retail portion of the venture.

Artist’s rendering courtesy of Wakefield Beasley Associates

The developer of a shopping center near the Portland-Westbrook line wants to add 750 apartments to the plan, which would make it one of the largest residential projects in the region.

The Westbrook Planning Board approved an application two years ago for a 500,000-square-foot retail plaza on vacant land surrounding the former Pike Industries quarry. Now, the Massachusetts-based developer that took over the project and secured the grocery store Market Basket as its anchor tenant is preparing to submit an even more ambitious plan: 1 million square feet of new housing and commercial space.

Brit Vitalius, president of the Southern Maine Landlord Association, said the project reflects a national trend toward urban living, where housing and businesses are integrated.

“We haven’t really seen this type of development here in the Portland area, but I think around the country, this is the trend,” Vitalius said. “It’s not all houses in one area and all commercial in another.”

Waterstone Properties Group has not submitted updated plans to the city, but it recently issued a news release with new details and renderings that depict two- to five-story buildings clustered around a plaza-like space with trees and grass. A call to the company was not returned Wednesday. A spokeswoman said via email that no one was available to speak about the project, but that Waterstone would be collaborating with local and state governments.

Westbrook City Planner Jennie Franceschi said she expects to meet with the developer next week to talk about the revised project. The Planning Board will need to approve the changes, but it’s unclear when the board will hold its first workshop with Waterstone.

“To put high-density residential next to commercial uses and services provides 24-hour usage of the property that a traditional plaza doesn’t get,” Franceschi said. “To have that sort of vitality on a site continually, all year long, all day long, is exciting.”

PUSHBACK ON BIG HOUSING DEVELOPMENTS

But housing developments with hundreds of units have faced pushback in recent years in Westbrook and Portland.

The original Midtown proposal in Portland would have built up to 850 apartments in the Bayside neighborhood. It was delayed for years because of local opposition and a lawsuit, and even though a scaled-down version won city approvals three years ago, the project appears to be dead.

In Westbrook, plans for 500 single-family homes and apartments inspired calls for a moratorium on new residential construction in 2016.

The developer’s news release suggests…