The Residences at Fresh Pond are planned to replace the structure at 70 Fawcett St. in the lower left, putting 429 apartments just off Route 16, at right, and a block from the Alewife T stop, top right. (Photo: Bing)

For those who thought The Residences at Alewife were big at 227 apartments, here come The Residences at Fresh Pond — 429 apartments to be built about a half-mile away.

The math shows the modest area expanding rapidly, adding 656 units and a thousand likely new residents and proving what city officials said Monday in discussing a possible high-rise (and another 259 units) on the other side of the city: While other cities languish in economic doldrums, Cambridge remains all but irresistible to developers.

A sprawling, two-story, 141,000-square-foot office building will be torn down for The Residences at Fresh Pond, which will go up just off Route 16, the Alewife Brook Parkway, and a block from the Alewife T station on the red line, New Boston Fund Inc. announced Wednesday.

While The Residences at Alewife were approved in March to replace the long defunct Faces nightclub on Route 2, the new complex will remove empty warehouse-style buildings at 70 Fawcett St. that once belonged to BBN Technologies, the acoustics and computing company bought by Raytheon Corp. in 2009. Raytheon remains a neighbor on Moulton Street.

Teardown and site work is to begin this year, said Brian Fallon, a partner at O’Connor Capital Partners, which bought the 4.9-acre site from New Boston Fund for an undisclosed amount.

A quitclaim deed recorded at the Middlesex Registry of Deeds showed $13.6 million paid from a Cabot, Cabot & Forbes address for 70 Fawcett St. on Sept. 27.

Eventually, O’Connor plans for a complex with “many amenities,” including a pool, fitness center, lounge and event space, Fallon said.

A study submitted in January described The Residences at Fresh Pond as consisting of two five-story buildings, one 105 feet high and the other 74 feet high. There would be 402 parking spaces, according to the study, and a traffic study found “no congestion or hazard will be created … the complex is designed to be pedestrian- and bicycle-friendly” as well as built in an environmentally conscious way that will win LEED certification.

The study’s description of the project:

Residential units with stoops, landscaping and terraces along Fawcett Street and the proposed future cross street. The parking garage entries are located off the side street to minimize the impact to Fawcett Street. The Project will also provide bicycle parking spaces within the garage and on the first floor to foster alternative transportation.

The Residences at Alewife on Route 2, also known as the Concord Turnpike, look to be oriented toward cars and luxury, including residents renting two-room apartments at up to $3,000 a month with use of yards, a heated pool, gym, community room, billiards room and screening room with a flat-screen television and cushy individual seats. There will even be a concierge, said builder Rich McKinnon and other employees of his McKinnon Co. The apartments should be ready for sale in the summer of 2013.

No builder is yet designated for The Residences at Fresh Pond. The sale was negotiated between New Boston Fund and Cabot, Cabot & Forbes on behalf of O’Connor Capital Partners, according to a New Boston press release.

It was New Boston Fund, a private equity real estate investment, development and management firm, that got approval from the city in 2008 to develop 260 units on part of the site. Before buying, O’Connor Capital Partners got approval for the remaining residential units, the New Boston Fund press release said.