Image courtesy of SGA

Life science developer Healthpeak is seeking to develop more lab space at a Waltham property it bought in 2020 for $320 million, providing expansion for existing tenants which include robotics manufacturer Boston Dynamics.

The Denver-based REIT is proposing a 141,000-square-foot expansion of the complex, known as Post @ 200 Smith. The former postal sorting facility was redeveloped as office and lab space by Boston-based Anchor Line Partners. Located on a 36-acre parcel, the facility is leased to Boston Dynamics, Deciphera Pharmaceuticals and ElevateBio.

The project requires a variance from the Waltham Zoning Board of Appeals.

“Denial of the requested relief limits the practical use of the existing facility, risking driving petitioner’s current tenant out, discouraging consideration of future tenants or possible buyers… and depressing the marketability and property value,” the zoning petition states.

The project would include a two-story addition to the 430,000-square-foot complex, including an underground parking level, and a separate five-story parking garage. The project would increase the property’s floor area ratio from 0.25 to 0.34, subject to the approval of a special permit from the Waltham City Council.

A ZBA hearing on the proposal will resume on June 6.

Healthpeak has made Greater Boston the focus of its East Coast expansion plans, with acquisitions and development plans in Cambridge and suburban markets.

The firm is planning a “mega campus” in West Cambridge’s Quadrangle after acquiring 36 acres of commercial parcels in late 2021, and is partnering with Bulfinch Cos. on a proposed redevelopment of the Muzi Ford property in Needham.