National Development's Ironworks development planned in South Boston. Image courtesy Elkus Manfredi Architects, ZGF Architects and COOKFOX Architects, DPC

Former executives for Boston-based construction firm Suffolk and Federal Realty Investment Trust are joining Newton-based National Development in high-level roles to oversee developments in South Boston and East Hartford, Connecticut spanning 2.2 million square feet.

Don Briggs, who was part of Federal Realty’s team that oversaw the 50-acre Assembly Row mixed-use development, and Suffolk executive Charlie Rollins were named senior vice presidents for National Development.

Briggs most recently was managing director of real estate at Boston-based Eastern Real Estate. In a previous position at Federal Realty, Briggs oversaw the buildout of the Assembly Row project in Somerville.

At National Development, he will be project executive for its Iron Works mixed-use development on Dorchester Avenue in South Boston.

As an executive for Suffolk, Rollins was responsible for managing Suffolk’s operations in Florida, and oversaw the $3.5 billion Water Street mixed-use development in downtown Tampa in a previous role at Strategic Property Partners.

In his new role at National Development, he will lead the firm’s redevelopment of a portion of the former Rentschler FIeld property in East Hartford as a 1.2 million-square-foot distribution center known as East Hartford Logistics & Technology Park.