A long-planned, 13-acre office park near the Springfield-Franconia Metro station could now include a multifamily component.

Monument Realty filed plans with Fairfax County to add a 300-unit residential building to the Liberty Park development, near the intersection of Beulah Street and the Franconia-Springfield Parkway, the Washington Business Journal reports.

The developer assembled the site in 2009, hoping to pull office demand from nearby Fort Belvoir. It received approval in 2010 for five office buildings totaling 750K SF and a 175-room hotel. But the area's office market has not been as strong as Monument hoped, so it is now adding a wider mix of uses to the development.

The latest application aims to replace one of the planned office buildings with a 300-unit multifamily building featuring 13K SF of retail, designed by DCS Design. The property sits within 2 miles of the Springfield Town Center Mall, the Walmart-anchored Kingstowne Town Center shopping center, and Northern Virginia Community College's Medical Education Campus.