Waltham Woods. Image courtesy of Newmark

Boston Properties is expanding its life science development activity with plans for additional lab projects along the Route 128 corridor.

The developer is beginning a speculative conversion of 880 Winter St. in Waltham into 224,000 square feet of lab space, executives said today during a conference call to discuss the company’s first quarter earnings.

“We have had significant tour activity and have begun making proposals,” President Doug Linde said during a conference call today to discuss the company’s first quarter earnings.

The building will be ready for tenant buildouts in the second quarter of 2022, Linde said.

And Boston Properties is preparing to break ground on at 330,000-square-foot lab building at 180 CityPoint in Waltham, next to its CityPoint office complex which recently reached 100-percent leasing.

Only 3 million square feet of the office REIT’s 51.6 million-square-foot portfolio is currently leased to life science tenants. But the company now has 2 million square feet of office-to-lab conversions under way and another 4 million square feet of ground-up development sites, primarily in Massachusetts and San Francisco.

Boston Properties acquired 880 and 890 Winter St., a 28-acre, 392,600-square-foot multitenant office campus known as Waltham Woods, in 2019 for $106 million.

On Tuesday, Boston Properties reported funds from operations of $243.8 million, or $1.56 per share, down from $284.1 million and $1.38 per share in the same quarter of 2020.

Notable local leases signed during the quarter included 63,500 square feet by Opthalmic Consultants of Boston at 195 West St. in Waltham and a 60,000-square-foot extension by a tech manufacturing company at 200 West St. in Waltham.