They have come, so developers will build it — housing, that is.

On Monday, the New London City Council named a prime developer for the long-vacant, 2.5-acre parcel at the corner of Howard and Bank streets known as “Parcel J.”

A.R. Building Co. — a soup to nuts operation that builds, owns and manages their housing complexes — plans a four-story structure with 90 apartments and retail services on the first floor.

Driving the development in large part is the growing number of engineers and other well-paid professionals working at the Electric Boat offices in the city, thanks to the accelerated submarine building and design schedule U.S. Rep. Joe Courtney, D-2nd District, has fought for in the defense budget.

The housing, aimed at young professionals, should serve as a catalyst for continued revitalization of the downtown.

Expect more development offers to follow, with builders expressing interest in the Fort Trumbull area and the development agency recently passing guidelines to assess the proposals. Give credit to Mayor Michael Passero for embracing the development efforts of the Renaissance City Development Association and giving it the financial means to hire an experienced and effective executive director, Peter Davis, the former Norwich planning director.

A.R. Building wants the option to convert the ground floor to residential if, after a couple of years, it can’t find retail tenants to fill that space. A mixed-use is preferable and the city should be a partner in trying to fill the ground floor with retail.

There are also concerns that parking may fall short of zoning requirements. Figure it out. Parking rules need to be flexible and solutions creative in an urban setting.

The big boost in employment at EB is good news, but it will be great news if hundreds of those employees are living, and spending, in New London.