ACS principal Patricia Simboli says the building will undergo an extensive overhaul, including a new roof, mechanical systems, electrical wiring and upgrades to the common areas. The property is adjacent to the firm's most prominent development in Chelsea, Harbour Pointe Park, which also serves as the firm's headquarters.

Despite the hefty investment required, Simboli says the firm is bullish on the project, adding that it has already leased out 20,000 sf to the Commonwealth of Massachusetts. Simboli maintains that the building offers a variety of benefits not seen in the suburban market, including an urban shopping district, a solid labor force and a location near Logan International Airport, which is barely two miles away.

"With Chelsea's proximity to Boston and Cambridge, it's easy access to the airport, and multiple modes of public transportation, 45-47 Spruce St. is a very exciting place to be," says Simboli. "There is a great deal of activity in the surrounding area."