Image courtesy of Elkus Manfredi.

A Massachusetts Turnpike air rights project already under construction plans to add a lab component for the Back Bay’s first major life science development.

Samuels & Assoc. said it’s planning to build 118,191 square feet of lab-ready space in its MassDOT parcel 12 project, which began construction in August 2020 at the intersection of Newbury Street and Massachusetts Avenue. The labs would be part of a 448,000-square-foot office-lab tower anchored by the future CarGurus headquarters.

“The leasing program has developed in response to demand for research and development space and based on changes in the office market,” developers wrote in a notification to the Boston Planning & Development Agency this week.

Acknowledging public concerns about the height of rooftop mechanical equipment on lab buildings, developers said the size and height of the 20-story building will not change. The mechanical equipment will be located within the existing building envelope, the filing stated.

The project also includes a citizenM Hotel located in a 13-story, 150,000-square-foot building on the northern side of the site.

IQHQ and Meredith Management are preparing to break ground on another Turnpike air rights project including a pair of office-lab building in the Fenway, the 720,000-square-foot Fenway Center.