Brandywine declined to disclose an estimated construction cost or anticipated rental rates. A spokesperson tells GlobeSt.com, "Brandywine is proceeding with this building on spec, but has strong prospects."

The five-story building, designed by Philadelphia-based Cope Linder Architects, will be made of granite and glass and have a two-story interior lobby. Pennoni Associates Engineering, also based in Philadelphia, is the consulting engineer. It is the same firm that provided engineering services for Brandywine's Cira Centre in Philadelphia.

The Metroplex site, located at the junction of Interstate 476, the Pennsylvania Turnpike and its Northeast extension, is master planned for up to 450,000 sf of development. In a statement, Philip Schenkel, VP of the northern suburban region, says the REIT is "continuing our investment in being the dominant landlord in this strategic transportation hub."

Brandywine, which is based here, already has an existing stake in Philadelphia's northern suburbs. The four-building Meeting House Business Center here is among them. It aggregates 140,000 sf, and this December, Schenkel told GlobeSt.com it was 96% leased. Brandywine also has office properties in Blue Bell, Horsham, Fort Washington and Bensalem, all of which are within a half hour from Metroplex center.

The Metroplex groundbreaking follows by just under six weeks, the close of the REIT's $3.3-billion acquisition of Dallas-based Prentiss Properties, which nearly doubled its portfolio. It is in the process of disposing of some of Prentiss' Dallas assets. To date, Brandywine owns, manages or has ownership interest in 45 million sf of office and industrial properties.