With the opening of the Silver Line, planners are hoping to increase the number of residents (and decrease the number of cars) in Tysons. But many are also wondering what effect the introduction of public transportation will have on other property types.

In terms of total office space, Tysons ranks third in the Washington market, below the D.C.’s East End and central business district, and just above Reston. Unlike the top two ranked office neighborhoods, Tysons did not have the benefit of Metrorail until last month. Will the commuting advantages brought by public rail serve as a catalyst for lots more office space?

Before construction of the Silver Line began in 2008, the amount of commercial space located within one-half mile of the first phase of the newest Metro line consisted of 20.75 million square feet. As is to be expected, the expansion of public transportation infrastructure attracted increased development.

In the six years since construction began, expanding the Metro’s service as far as Wiehle Avenue in Reston, that same half-mile corridor has seen more than 1.5 million square feet of space built. The majority of that space is in Tysons’s tallest and most prominent new office building, Tysons Tower. Coming in at just over 528,000 square feet, the property was 40 percent leased before construction was complete in large part because of its proximity to Tysons Corner station.

With the completion and opening of the Silver Line’s first phase, developers are still confident that both phases of the new Metro line will bring more people to live, work and play in this area of Northern Virginia.

Within one-half mile of the Silver Line’s first phase, more than 6 million square feet of new commercial space is under construction or proposed with a completion date by 2018, when the second phase of the rail line to Dulles is set to open.

In the same half-mile distance from phase two of the Silver line, developers have plans for another 4.2 million square feet of space set to be complete by 2018. More than half of that total is in seven new multifamily projects that would add more than 1,700 new, Metro-accessible apartment units in Fairfax County.

While phase one is complete and phase two is still four years down the road, those living and working in the Silver Line corridor should get used to being in the shadow of cranes for some time to come.

Kirstie Boatright is a research manager for CoStar Group in Washington.