The approval of a proposed residential development will add a new, 104-unit, 12-story residential complex in the Fort Myers Heights area of Arlington County while guaranteeing the preservation of three 1940s-era garden apartment complexes, Arlington County Board members said Saturday.

“This project preserves an important part of Arlington’s legacy,” Arlington County Board Chairman Chris Zimmerman (D) said.

The Wakefield Manor, Wakefield Annex and Courthouse Manor apartments that take up three-quarters of the site are examples of the early 20th-century rental-housing boom spurred by the establishment of the Federal Housing Administration and were designed by well-known architect Mihran Mesrobian, who designed the Hay-Adams Hotel and the Wardman Tower in the District. Mesrobian was also developer Harry Wardman’s chief architect in Washington.

The project developer, Virginia Land Trust, plans to build the high-rise apartments at North Troy Street and Fairfax Drive, overlooking Route 50, on a quarter of the 1.8-acre site on land that is a parking lot.

The construction will not disturb many of the mature trees or the open space, and its facade is planned to be compatible with the older complexes. Almost all the parking, including spaces for bicycles, will be underground. The developer will also contribute $75,000 to the county’s public art fund.

Several new units will be affordable housing, or else the developer will pay $384,109 to the county’s affordable housing fund, officials said. In addition, the existing affordable housing in the garden apartments will remain as such for the next 30 years.

An effort to calm residents?

Arlington County Board members unanimously passed a series of projects to calm neighborhood traffic this weekend, but support among residents wasn’t as consistent. Sixty-five similar measures have been built in Arlington County in the past decade — and they still stir up emotions.

The installation of curb bump-outs, humps and similar structures in the Arlington-East Falls Church and Douglas Park neighborhoods — specifically, on 26th Street North between Quantico and Sycamore streets and on 16th Street South between South Monroe and South Quincy streets — are intended to slow speeders, many of whom use the residential streets as a cut-through to arterial roads, county officials said. The idea got a thumbs-up from most of the neighbors who responded to county surveys and from most of the 15 people who spoke at a County Board meeting Saturday.

But several residents voiced concerns about the $224,000 total price tag, the possible effect on emergency response times and the perception that anti-traffic activists are trying to keep traffic out of their own neighborhoods. Zimmerman lives near one of the affected areas.

County staff said the traffic-calming devices would impose a “negligible delay” for school buses, fire trucks and other public transportation because the speed humps have gaps that allow emergency vehicles to pass through them without contact.

Zimmerman defended the process in the face of the controversy.

“It isn’t failure because people disagree. This is a democracy . . . We make compromises, [and] we wind up with something that is a balance,” he said.

Construction on the projects is expected to begin next summer.