D.C. Code § 1-306.31

The housing linkage objective is to require applicants who obtain bonus commercial office space as a result of a discretionary and otherwise appropriate street or alley closing or zoning density increase to produce housing or contribute funds to the production of housing, particularly housing that is affordable to low- and moderate-income households throughout the District, in an amount based on a formula tied to the amount or value of the additional commercial office square footage obtained.