Image courtesy of DLJ Real Estate Partners and Leggat McCall Properties

After leasing up their first lab tower and receiving $246 million in construction financing to start a second, Boynton Yards developers are moving forward with a third lab tower in the 1.9 million-square-foot master-planned project.

Leggat McCall Properties and DLJ Real Estate Partners propose a 360,000-square-foot office-lab tower at 99 South St., including ground floor space that will be reserved for arts and creative uses.

The 12-tower will include 5,000 square feet of arts and creative uses and 260 below-grade parking spaces.

The development originally spanned 6.5 acres of former industrial properties and parking lots and expanded to 7.9 acres with the $60 million acquisition of the 561 Windsor St. building in 2021.

Construction of an 11-story, 353,000-square-foot lab tower at 808 Windsor St. began after developers received a $246-million construction loan in December.

Union Square master developer US2 broke ground in 2021 on a 194,000-square-foot lab tower on Prospect Street and received approval in March for a second life science building at 600 Windsor Place.