Amazon is taking another step to support affordable housing development in the area around its HQ2 campus.

The tech giant announced Tuesday it donated $40M of vacant land next to the Crystal House apartments to Arlington County to help build a 550-unit affordable housing project.

The move comes after Amazon in January announced it was providing a $339M below-market loan and $42M in grants to the Washington Housing Conservancy to acquire and preserve the affordability of the 828-unit Crystal House property at 1900 South Eads St. That deal gave Amazon a $40M option right on undeveloped land on the 16-acre property, and it is now assigning that option right to the county.

The county will select a developer to build the project, Amazon said in the announcement. It expects construction will begin in 2025 on the project consisting of more than 550 new units of affordable housing for those earning up to 80% of the area median income, bringing the property's total unit count to over 1,300.

“We are excited to build on our earlier work to preserve affordable housing at Crystal House in the heart of our new headquarters," Amazon Head of Community Development Catherine Buell said in a release. "This donation to the county brings us a step closer to achieving up to 1,300 total affordable homes at the site for families earning moderate- to low-incomes.”

The property sits within the National Landing neighborhood, where Amazon broke ground in January 2020 on the first two new office buildings on its HQ2 campus. It already has more than 1,600 employees in space it is leasing from JBG Smith in the neighborhood.

"By assigning its option on the undeveloped land at Crystal House to Arlington County for the creation of additional  affordable housing, Amazon is reinforcing its strong commitment to ensuring that National Landing provides quality housing options for residents of all income levels,” National Landing BID President and Executive Director Tracy Sayegh Gabriel said in a release.

Amazon also announced last month it would contribute $125M in below-market loans through a partnership with transit agency WMATA to help create 1,000 units of affordable housing at Metro stations over the next five years. The Crystal House and WMATA contributions both came from the $2B Housing Equity Fund that Amazon announced in January.