Zoning Ordinance Rewrite Change Highlights - Chapter 5: Overlay Districts

An overlay district is a zoning designation laid on top of the underlying base zoning district. Any land located within an overlay district must comply with both the regulations for the base zoning district and the regulations for the overlay district.  

Chapter 5 of the new Zoning Ordinance prescribes regulations for seven overlay districts in Loudoun County: 

  • Airport Impact Overlay District (AIOD) 
  • Floodplain Overlay District (FOD) 
  • Mountainside Overlay District (MOD) 
  • Limestone Overlay District (LOD) 
  • Quarry Notification Overlay District (QNOD) 
  • Village Conservation Overlay District (VCOD) 
  • Historic Overlay District (HOD) 

The new Zoning Ordinance retains the Route 28 Corridor Overlay District as a legacy district.  

 Airport Impact Overlay District 

The Airport Impact Overlay District (AIOD) regulates the location of noise-sensitive uses, such as residences, and ensures building heights do not conflict with federal regulations. In January 2023, the Board of Supervisors adopted amendments to the county’s Airport Impact Overlay District (PDF). As part of the Zoning Ordinance Rewrite, the Board of Supervisors made minor changes to replace “disclosure statement” with “notification” and delete the requirement to include AIOD notifications in sales contracts.  

Floodplain Overlay District  

Floodplain Overlay District (FOD) regulations in the previous Zoning Ordinance have been maintained in the new ordinance. Updates to the FOD are planned in a standalone effort following completion of the Zoning Ordinance Rewrite project. The future standalone effort will accommodate federal and state review timelines set by the Federal Emergency Management Agency and Virginia Department of Conservation and Recreation.  

Mountainside Overlay District 

The Mountainside Overlay District (MOD) regulates activity within sensitive mountainside areas to minimize disturbance or destruction of critical ecological resources, protect water quality and quantity, and minimize slope failure and earth movement. The previous and new zoning ordinances map regulate three mountainside areas—highly sensitive, sensitive and somewhat sensitive—which are defined according to the natural presence of elevation, forests, steep slopes, unstable soils and groundwater recharge areas.  

The new Zoning Ordinance strengthens the MOD with a 300-foot setback from new Ridgeline and Spring features. Development, land disturbance and uses must be located outside of the identified features and must follow development standards for tree clearing, grading and other land disturbance. Exceptions allow the following to locate within the new Ridgeline features: agriculture, public roads, public water and sewer, fences and public trails. 

Limestone Overlay District 

The Limestone Overlay District (LOD) is largely retained from the previous Zoning Ordinance. Protections have been carried forward in the new ordinance, such as setbacks from identified karst/sensitive environmental features, prohibited pollution sources and development standards to protect water resources and minimize the potential for property damage from earth movement. The new Zoning Ordinance adds administrative flexibility to the development standards within the LOD for a deck when a geophysical study does not identify any karst/sensitive environmental features. 

Quarry Notification Overlay District  

The Quarry Notification Overlay District (QNOD) requires written disclosure to prospective property buyers that the property they are purchasing is located within an area that may be impacted by quarrying activities and blasting. The QNOD regulations have been substantially carried forward from the previous zoning ordinance. 

Village Conservation Overlay District  

The Village Conservation Overlay District (VCOD) helps ensure that new development or additions to existing buildings within the county’s 13 historic villages is compatible with the pattern, character and visual identity of the existing villages. The new Zoning Ordinance carries forward the development standards from the previous ordinance and adds the following new development standards:   

  • Building height for any new building cannot exceed 25% of the average height of the principal buildings (with the same number of stories) on the same side of the road within 150 feet of both sides of the lot or lots being developed. 
  • For new subdivisions of six or more lots, the maximum lot width must be within 51% of the average of the smallest lot width and the largest lot width of existing residential lots that are located within 300 feet of the subject lot or lots to be subdivided. This requirement does not apply if the subject lot or lots to be subdivided is/are not within 300 feet of an existing residential lot in the VCOD.  
  • New garages must be detached from the principal building. 

The enhanced development standards are intended to be an interim measure to minimize impacts of new development until the completion of Small Area Plans for each village. 

Historic Overlay District  

The Historic Overlay District (HOD) governs the maintenance of existing structures located within the overlay district and sets forth the regulations for proposed activities requiring the approval of a Certificate of Appropriateness (CAPP), such as structural alterations, demolition, restoration, new construction and changes to signs. The HOD regulations in the new ordinance are largely unchanged from the previous ordinance. 

Review additional details in the Loudoun County Zoning Ordinance.

Last updated 12/18/2023