"It's a great building in a market with not a lot of large blocks out there," DeSimone tells GlobeSt.com in predicting that 52 Second Ave. will be well-received. JLL has undertaken a "soft marketing" approach to date, relays DeSimone, who says the opportunity is already garnering inquiries. Industry observers do not seem surprised.

"That's beautiful space," says one broker active in the market who maintains there is upwards of 14 years remaining on the lease and indicates that a tenant could also benefit from the "plug-and-play" nature of the opportunity, offering those who desire turnkey convenience. The location providing direct access—and visibility—to Route 128 is another attraction, says the broker.

The source and others also report the space will be offered in the mid-$30 per sf range, allowing for a discount to Class A office product under construction just up the street. Those ventures by developers including Boston Properties, Normandy Real Estate Partners and Neelon Properties are said to need $40 per sf commitments to justify building along the coveted Waltham strip. "It has to be a concern," opines the broker tracking the sublease. "That's a big chunk of space and a lot of term left, and (National Grid) can be competitive."