Coresite 12100 SV & 12098 SV data center, Reston, Virginia

CoreSite is expanding its Reston, Fairfax County, Virginia, data center campus at 12369 Sunrise Valley Drive with a three-story, about 215,000-square-foot, 75-foot-tall building called V3 Phase 2, which would replace a vacant one-story office building next to homes on Cocquina Drive. Fairfax County staff received the site plan, submitted June 20, 2025, and county rules let staff approve it 30 days after the notice to neighbors was postmarked; no report of that approval or denial has been published since.

The building is part of a development plan the Board of Supervisors approved in 2018 for the former Sunrise Technology Park, which CoreSite bought from Brookfield Properties in 2016 for $60 million; when the full plan is built, CoreSite will have 1.3 million square feet of data centers in Reston. CoreSite already runs its VA1 and VA2 buildings at 12100 Sunrise Valley Drive, a former AOL site opened in 2008, and its VA3 campus at 12369 Sunrise Valley Drive, which includes two renovated 1980s office buildings and a two-story data center added in 2019.

Most Cocquina Cluster residents learned of the plan only when a neighbor asked about it on a community Facebook group on June 16, 2025, after a notice letter listed the wrong address, 12098 Sunrise Valley Drive, across the street. "That feels, at best, careless," said Maggie Urbanik, president of the Cocquina Cluster Homeowners Association, who said at worst it was intentionally misleading. Resident Caitlin O'Dwyer called the existing building "an absolute blight" and said its evaporative cooling system is already having a visible effect on the neighborhood.

CoreSite's mid-Atlantic general manager, Chris Lettiere, said the expansion would create about 300 construction jobs and 50 permanent jobs, and that the company is working closely with the county on permitting, without addressing residents' specific concerns. Fairfax County adopted new data center rules in 2024, including a ban on facilities within 200 feet of homes, but Hunter Mill District Supervisor Walter Alcorn's office confirmed they do not apply to CoreSite's already-approved plan.