A view of the Rosslyn skyline as seen from Georgetown. (Jeffrey MacMillan/Capital Business)

Construction noise echoes off Rosslyn’s office towers most lunchtimes, as hungry workers throng food trucks clustered along North Lynn Street and fill sidewalk tables set up by takeout cafes.

Eight hours later, everything is quiet. The food trucks are gone, the restaurants are closed and the people have disappeared.

Welcome to Arlington County’s high-rise downtown, a concrete canyon where nightlife goes to die — and where, in recent years, the commercial vacancy rate has climbed to 30 percent.

County officials want to remake the neighborhood into a more dynamic, walkable mix of workplaces, housing, retail and public spaces, with attractive modern buildings that they think will draw both commercial and residential tenants.

It’s a formula that Arlington pioneered decades ago, when it built shops, offices and apartments around Metro stops in Clarendon, Ballston and the Court House neighborhood. The concept is now being tried in many aging neighborhoods, including Tysons Corner and the Seven Corners area of Fairfax County and the White Flint neighborhood in North Bethesda.

The 1812 North Moore Street building sits empty in Rosslyn. (Jeffrey MacMillan/Capital Business)

The Arlington County Board last week advanced the vision for Rosslyn, approving a pair of land-use plans that lay the groundwork for high-rise buildings to reach higher, and for the creation of attractions to add residents and visitors who stay long past 5 p.m.

“Rosslyn is critical. It is our front door,” said Victor Hoskins, the county’s director of economic development. “It’s a bellwether for where our market is going.”

The office vacancy rate is alarming in a county in which commercial property taxes provide about half the government’s operating revenue. Hoskins said it is costing Arlington $34 million per year.

He said he would like Rosslyn to become more lively, perhaps luring some of the crowds from Georgetown, the tourist-filled D.C. neighborhood just across the Potomac. Think of it as a “symbiotic relationship,” Hoskins said, like Brooklyn is to Manhattan, Bellevue to Seattle, or Cambridge to Boston.

The Rosslyn Sector Plan, a broad outline of what the county plans over the next 25 years, envisions parks and plazas east of the Rosslyn Metro station that could host festivals and other public events. An expanded 18th Street corridor would create a “central spine,” or green walkway, through Rosslyn’s midsection to the eastern edge, modeled in part on New York’s High Line Park.

The plan calls for remaking Gateway Park, a green-and-concrete space that is isolated between Lee Highway and the Key Bridge Marriott, into something more active; and for building a pedestrian and bicycle bridge to connect Rosslyn with the regional trail system, Roosevelt Island and the Potomac. Several major one-way streets would become two-way streets, and that change would slow traffic and be more pedestrian-friendly, officials say.

At full build-out, planner Anthony Fusarelli said, Rosslyn would have 19.3 million square feet of office, retail and housing space, about twice what’s available today. Between 7,000 and 8,000 people could move in, joining the 10,800 who live there now.

By far the most controversial part of the plan is the decision to end Rosslyn’s 300-foot building height limitation, which will be replaced with a “peaks and valleys” concept that could allow buildings up to 390 feet high in some places, but will still protect views from a 31st-floor public observation deck at the under-construction Central Place.

The Central Place project, on Wilson Boulevard between Lynn and Moore streets, is one of two that received permission from the county in 2007 to exceed the 300-foot limit. The other is the 384-foot office building at 1812 N. Moore. It is the region’s tallest building, and it is vacant.

Arlington lawmakers also approved a plan for western Rosslyn last week that will reduce the size of the heavily used Rosslyn Highlands Park in order to make room for more offices and apartments, replace an old fire station and add a sorely needed school and more affordable housing.

Neighborhood residents who opposed the arrangement argued that public parks and playgrounds are valuable features, especially for apartment and condominium dwellers, and should not be encroached upon.

In downtown Rosslyn last week, workers in the daytime crowd said they would welcome the changes outlined in the planning documents.

“We’re all busy and passing through,” federal contract specialist Amy Davis said Thursday, standing in line at a tapas food truck as scores of others on their lunch breaks pressed past. “There’s no sense of community.”

About 28,000 workers come to Rosslyn’s buildings on weekdays. But the neighborhood desperately needs more nightlife, said software developer Michael Burns, and better places to stroll.

“There are very few places to go for happy hour,” said Burns, sitting in a pizza place with co-worker Craig Eddy. “You’d never be able to tell the river is near here.”

Six students from the Art Institute of Washington threaded through the lunchtime crowds, as a small squad of uniformed soldiers from Joint Base Myer-Henderson Hall strode to the Metro, and a few visitors wandered in search of the Iwo Jima Memorial.

The students were examining Rosslyn’s streetscapes and eco-friendly buildings for a class assignment. Cindy Blassingame, 57, an Army veteran working on her third degree, said she and her classmates found a lot to like but had a few suggestions.

“We’d reduce the number of cars,” Blassingame said. “And I’d build more multi-use buildings with amenities like gyms, restaurants, day cares.”