Image courtesy of Lincoln Property Co.

Special permits have been approved for conversion and expansion of a 53-year-old office building overlooking Route 128 into a 140,000-square-foot lab complex.

Scheduled for completion in 2021, the project at 300 Third Ave. in Waltham received final permitting approval from local officials.

Designed by Boston-based architects DiMella Shaffer and AHA Consulting Engineers of Cambridge, the project will provide flexible space on four levels with 35,000-square-foot floor plates. Four parking levels will contain over 400 spaces.

Led by Lincoln Property Co., the project will transform an office building originally completed in 1966 into a multi-tenant building with flexible and customizable office and lab space, Lincoln Property announced this week. Waltham-based Crosspoint Assoc. owns the property, featuring a 21,000-square-foot mirrored-facade office building on 1.7 acres.

LPC Boston | 300 Third Avenue, Waltham, from Lincoln Property Co. on Vimeo.

“Our experience in life sciences started back in the 1980s with the genesis of the Kendall Square biotech hub and our design of the Biogen facility,” Randy Kreie, principal and president of DiMella Shaffer, said in a statement. “We continue to be excited by the growth in the industry in Greater Boston and we’re honored to work with Lincoln Property Co., especially on such a special and iconic project.”

Lincoln Property’s Jeff Moore and Chris Devaux are representing the firm in leasing.

Lab conversions have become a favored option for office building owners in the Route 128 market that are seeking to capture spillover demand for growing life science companies outside of Cambridge.

Boston Properties recently announced it will convert the 256,245-square-foot 200 West St. in Waltham into lab-ready space, and design a 300,000-square-foot building at CityPoint in Waltham for lab standards.

And Burlington-based Gutierrez Cos. is partnering with GEM Realty Capital of Chicago to convert a 110,000-square-foot office building at 4 Burlington Woods into lab-ready space after failing to attract an office tenant for the speculative project.