Amazon's footprint is expanding once again in Northern Virginia, this time with a trio of buildings in Loudoun County.

Amazon Data Services Inc. bought three Sterling office buildings at 46000, 46010 and 46020 Manekin Plaza, the Washington Business Journal first reported. The previous owner is listed as SIP/CREF Manekin Plaza LLC, according to public records. The deal closed on Dec. 21.

The $21M deal will net Amazon 252K SF of offices, but based on the purchasing entity, future data center space appears to be on the table — whether it would come via a retrofit or new construction is unclear. The buildings, which were constructed in 1989, appear to house a U-Haul, engineering firm and other businesses.

Amazon's real estate strategy has evolved quickly over the past two years. Last fall, Bisnow reported that Amazon was increasingly buying and developing its own industrial space instead of leasing it, spending $450M in the span of a year to acquire space.

Loudoun County is also the epicenter of a data center boom that has seen steady growth for years. Earlier this month, American Real Estate Partners announced a joint venture with Harrison Street to create 2.1M SF of new data centers in Ashburn and Arcola.