Image courtesy of SMMA

The next phase of BioMed Realty’s first lab development in Boston’s South End would add 237,000 square feet of life science space through an office conversion.

BioMed Realty previously developed a 220,000-square-foot lab building at 321 Harrison Ave., which connects to an office building that it also owns at 1000 Washington St.

The life science developer this week began permitting for the second phase of the project, which would convert the office building to lab space.

The project includes upgrades to the building’s foundation and columns to support the additional loads needed for lab space, and conversion of an 11th floor cafeteria to tenant space, according to a filing submitted to the Boston Planning & Development Agency.

BioMed has notified neighborhood groups and nonprofits in Chinatown and South End about the latest project. The 321 Harrison Ave. approval was delayed in 2021 after BPDA directors demanded more outreach to non-English-speaking residents.

BioMed has leased 90 percent of the space at 321 Harrison Ave., developers said.