A street grid populated with more modern buildings is beginning to emerge in the Mosaic District, which is the core of the new town center plan, and beyond. “There’s more to be done, but you can see the final result in your mind’s eye without too much effort,” Mr. Connolly said.

The company behind the latest stage in Merrifield’s evolution is Edens, a private retail developer based in Columbia, S.C., that owns more than 130 shopping centers. “This was the right project, in the right place, at the right time, by the right developer,” said Barbara Byron, director of Fairfax County’s Office of Community Revitalization. “The vision that they presented was exactly what the county was looking for as the Merrifield Town Center.”

Edens found Merrifield, which is about 15 miles from Washington, enticing. “There are very few sites left in the country that are undeveloped and that have the density and strength of a permanent and daytime consumer base within a 10-minute drive time,” said Jodie W. McLean, the president and chief investment officer for Edens, who found the local market statistics — 10 million square feet of office space within a mile and an average household income of $173,338 within a five-mile radius — irresistible.

The result was the 31-acre Mosaic District, which opened this fall with shops and restaurants, an Angelika Film Center, a 150-room Hyatt House hotel, and 73,000 square feet of office space. While much of the retail has been leased, the offices are still awaiting the first tenants. Named Mosaic to refer to the many different Northern Virginia neighborhoods that encircle Merrifield, the project is divided into four geographic districts: fashion and retail; film and dining; market, which includes specialty food shops; and residential.

Eventually, the LEED-certified development will include a total of 500,000 square feet of retail and 1,000 residential units. The housing will be built by rental apartment developers AvalonBay and Mill Creek Residential, with townhouses for sale built by the home builder EYA of Bethesda, Md. A handful of the residences will be designated as affordable housing for qualified applicants.