Zoning Ordinance Rewrite Change Highlights - Chapter 9: Attainable Housing

One of Loudoun County’s goals is to promote attainable housing options through development that includes new housing opportunities that address a greater number and a wider diversity of needs. To help achieve this goal, the new Zoning Ordinance includes increased flexibility and more opportunities to modify the regulations, which are intended to incentivize developers and equip them to creatively address the county’s unmet housing needs.  

Chapter 9 of the new Zoning Ordinance provides regulations for three attainable housing programs: Affordable Dwelling Units, Unmet Housing Needs Units and Affordable Housing Units. This chapter specifies how many and what type of attainable housing units a developer must provide as part of a residential project and provides standards to help ensure the attainable units look similar to and are mixed in with non-attainable housing units.  

The Area Medium Income (AMI) for Loudoun County is currently $152,000 a year for a family of four. 

Affordable Dwelling Unit Program 

The Affordable Dwelling Unit (ADU) program assists residents with incomes between 30% and 50% of the area median income (AMI) for those wishing to rent; and 30% to 70% of the AMI for those wishing to purchase a home. Highlights of how the ADU program in the new Zoning Ordinance differs from the previous ordinance include: 

  • Requires all residential developments with 24 or more dwelling units that are served by public water and sewer to provide ADUs. The previous ordinance excluded developments with a density less than one dwelling unit per 40,000 square feet. 
  • For apartment buildings served by an elevator, buildings with eight or more stories are not required to provided ADUs, an increase from buildings with four or more stories in the previous ordinance. 
  • Increases the percentage of dwelling units a developer must provide as ADUs for single-family dwelling units from 12.5% to 15% and for multifamily dwelling units (apartments) from 6.25% to 10%. 
  • Increases the optional density increase for multifamily projects (apartments) from 10% to 20%. 
  • Requires ADUs to represent the different dwelling unit types in the development and allows single-family detached ADUs to count as 1.25 ADUs. 
  • Provides criteria for evaluating whether ADUs are compatible and mixed in with the non-ADUs. 
  • Allows modifications of required ADUs by dwelling unit type, the percentage of ADUs required and the timing of ADU construction.

Unmet Housing Needs Program 

The Unmet Housing Needs Unit (UHNU) program is a new attainable housing program in the new Zoning Ordinance. The UHNU program complements the ADU program by promoting housing for households with incomes not addressed by the ADU program, such as those wishing to rent with incomes between 0% to 30% of the AMI; and with incomes between 70% to 100% of area AMI for those wishing to purchase. The UHNU program:  

  • Regulates UHNUs when developers voluntarily provide them in exchange for an increase in Floor Area Ratio in certain parts of the Transit Related Center (TRC) Zoning District, as adaptive reuse of a historic building, or as part of a rezoning.  
  • Allows Affordable Housing Units (AHU) to be substituted for UHNUs. 
  • Provides criteria to evaluate whether UHNUs are compatible and mixed in with units that are not UHNUs. 
  • Allows the timing for constructing UHNUs to be modified.

Affordable Housing Units Program 

The Affordable Housing Units (AHU) program establishes regulations for developers to provide AHUs to substitute for required ADUs or UHNUs. Highlights of the differences for the AHU program between the previous ordinance and the new ordinance are: 

  • Revises the timing for when AHUs must be constructed, to allow projects providing 100% of the ADUs and/or UHNUs as AHUs to construct more than 50% of the non-attainable housing units sooner. 
  • Requires AHUs to be compatible with non-attainable housing units and includes exemptions for projects funded by certain programs, such as the Low-Income Housing Tax Credit. 
  • Allows the compatibility requirements to be modified.

Review additional details in the Loudoun County Zoning Ordinance.

Last updated 12/18/2023