"It's a terrific location for a first-class office building," says a broker familiar with the property on Jones Road. The source also maintains that the development will be well-received by companies scrambling to find adequate quarters. "The marketplace needs the space," says the source. "In all areas, we are badly undersupplied."

Nowhere is that more true than in Waltham, considered the most desirable office destination in the suburbs. With a 4.7% vacancy rate, according to Meredith & Grew, the 20-million-sf Route 128/Mass Pike submarket has barely 900,000 sf available, and virtually nothing contiguous over 50,000 sf. After beginning the year with rental rates in the mid-$30 per sf range, Waltham is now commanding rents above $50 per sf.

Boston Properties Senior Vice President Claude Hoopes says that because several projects under construction have already leased up, the effective vacancy rate for Waltham is between 2% to 3%. When the Waltham Weston Corporate Center is completed in 15 months, Hoopes believes the six-story building will be well on its way to being fully committed."It's going to be one of the only games in town in that submarket over the next 24 months," he says. "It's just an incredibly tight market."Hoopes says Boston Properties has the capacity to construct another building at the development, adding that the firm had mulled increasing the initial phase to between 375,000 sf and 425,000 sf before opting to focus on one structure for the time being. ADD Inc. of Cambridge is the architect.