At its January 17, 2023 meeting, the Loudoun County Board of Supervisors approved changes to the county’s Comprehensive Plan, Zoning Ordinance and zoning map pertaining to land development in areas where airport noise impacts are known to occur currently and expected to occur in the future as airport traffic increases.
The Airport Impact Overlay District (AIOD) is a zoning designation for properties where airport noise is anticipated at specified levels. Properties located within the AIOD are subject to certain land use regulations. The AIOD was implemented by the Board of Supervisors in the early 1990s to mitigate impacts to prospective homebuyers in areas that would be affected by aircraft noise and to prevent residential development in areas where the highest noise impact to people on the ground is anticipated to occur.
Why did the County Make Changes Now?
The Metropolitan Washington Airports Authority (MWAA), which operates Dulles International Airport, updated its noise exposure maps for Dulles Airport in 2019. As a result, Loudoun County’s previous AIOD was outdated. Based on the airport’s updated noise exposure maps, Loudoun County worked collaboratively with various stakeholders for more than two years to update the boundaries of the overlay district as well as the county’s land use policies and zoning regulations related to the AIOD.
Board of Supervisors’ Vote to Approve
The Board of Supervisors considered many factors, such as information provided by MWAA, input from area residents and homeowner associations, recommendations from the Planning Commission and research conducted by county staff.
The Board ultimately voted on January 17 to:
- Adopt the proposed amendments to the county’s Comprehensive Plan and Zoning Ordinance and zoning map. The updated plan and regulations:
- Do not add previously approved residential developments into the area designated with the highest noise impact; however, some existing homes may move into a different AIOD designation based on the newly adopted boundaries in the updated map.
- Prohibit new residential developments in the area with the highest noise impact.
- Require home sellers to disclose the property is within an AIOD at the time of sale.
- Require specific disclosure language for homeowner association declarations in new developments, which must clearly state that the community is located near an airport, may be impacted by overflight noise, and is subject to the regulation of the AIOD of the Loudoun County zoning ordinance.
In addition, the Board voted in favor of opening a dialogue with the Federal Aviation Administration to better understand the future options available that would address community concerns regarding airplane noise.
The Board’s vote does not impact the AIOD boundaries surrounding Leesburg Executive Airport.
Who is Impacted?
The amendments to the AIOD map affect approximately 59,000 properties around and near Dulles Airport, including those removed from the overlay district.
Impacted residents may view the interactive map illustrating the adopted Airport Impact Overlay District to identify the current AIOD designation for their properties based on the Board’s vote. The map allows users to “turn on” the previous AIOD for comparison.
In some instances, the AIOD boundaries bisect individual properties. Any property owner with questions about how the adopted AIOD impacts their property may contact the Loudoun County Department of Planning and Zoning by email or by phone at 703-777-0246.
About the Airport Impact Overlay District
Loudoun County government cannot regulate airport noise or control flight paths; however, the county can update its policies and regulations regarding the use of land around the airport. The AIOD is a zoning tool to plan appropriate land uses in the areas where airport noise is known or expected to occur.
There are three Aircraft Noise Impact Area designations within the AIOD that the county uses to indicate the level of impact. The AIOD regulations stipulate specific land use rules for each designation, which are intended to mitigate the impact of noise. The county refers to these levels using the symbol “Ldn,” which stands for “yearly day-night average sound level.” The Ldn is calculated using a specific formula specified in the county’s zoning ordinance. The designations are:
- Ldn 65 or Higher: Properties located within this area are closest to the airport. New residential development is not permitted in this area.
- Ldn 60-65: Properties located within this area are closer to the airport. Any residential development in this area requires disclosures at the time of sale; acoustical treatments for new residential construction and new additions to existing residences; and an easement established prior to construction of a new residence granting the right of overflight in the airspace above the property.
- One-Mile Buffer: Properties located within this area are farthest from the airport while still being located within the AIOD. This designation requires a disclosure notice to be included with each sale of residential property.
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