Impact of the AN: Airport Noise Overlay District on Orlando Base Zoning Standards
The Orlando AN: Airport Noise Overlay District imposes significant land use prohibitions and construction requirements to mitigate aircraft noise impacts, including the total prohibition of new residential development in Zones A and B. Depending on the specific Noise Zone, the City of Orlando requires new structures to achieve Sound Level Reductions (SLR) of 25 db, 30 db, or 35 db through specialized building materials and design. Furthermore, property owners within these zones must often provide avigation easements or waivers of noise claims to the City of Orlando as a condition of development approval.
Overview and Relationship to Base Districts
The AN: Airport Noise Overlay District serves as a supplemental layer of regulation for properties in the vicinity of the Orlando International Airport (OIA) and the Orlando Executive Airport (OEA). The requirements found in the Orlando AN: Airport Noise Overlay District are intended to supplement all other zoning districts in which land may be classified [Section 58.371].
Crucially, when an area is located in more than one described airport height zone or airspace surface, the property must comply with the most restrictive height limit or surface requirement [Section 58.1223]. If any provision of the Orlando AN: Airport Noise Overlay District conflicts with another code or ordinance of the City of Orlando, the provisions of the overlay shall govern and control [Section 58.371].
Noise Zone Classifications
The City of Orlando establishes five distinct Aircraft Noise/Land Use Control Zones based on Day-Night Sound Level (DNL) contours and single-event noise measures (dBA) [Section 58.372]:
| Zone | Noise Metric / Contour |
|---|---|
| Zone A | 75 and greater DNL contour |
| Zone B | 70 to 75 DNL contour |
| Zone C | 65 to 70 DNL contour |
| Zone D | 60 DNL to 65 DNL (and 80 dBA Metric) |
| Zone E | 55 DNL to 60 DNL (and 75 dBA Metric) |
Modifications to Residential Land Use Standards
The Orlando AN: Airport Noise Overlay District strictly limits or prohibits residential uses that might otherwise be permitted by a property's base zoning [Section 58.381]:
| Use Type | Zone A | Zone B | Zone C | Zones D & E |
|---|---|---|---|---|
| Single Family | Prohibited | Prohibited | Discouraged | Permitted |
| Multi-Family | Prohibited | Prohibited | Discouraged | Permitted |
| Mobile Homes | Prohibited | Prohibited | Prohibited | Permitted |
| Hotel/Motel | Permitted* | Permitted* | Permitted | Permitted |
*Permitted only with appropriate controls and prior agreements [Section 58.381].
Required Noise Controls and Construction Standards
For uses that are permitted, the City of Orlando mandates specific structural and legal controls based on the noise zone [Section 58.381].
Residential Control Requirements
Residential uses, including hotel/motel and timeshares, must adhere to the following standards:
| Control Zone | Avigation Easement | Waiver of Claim | Notification | Required SLR |
|---|---|---|---|---|
| Zone A | Required | Required | Required | N/A (Prohibited) |
| Zone B | Required | Required | Required | N/A (Prohibited) |
| Zone C | Required | Required | Required | 35 db (SF) / 30 db (MF) |
| Zone D | Not Required | Required | Required | 25 db |
| Zone E | Not Required | Not Required | Required | Not Required |
Non-Residential Control Requirements
Sensitive non-residential uses (hospitals, clinics, nursing homes, childcare, and schools) are subject to the following:
| Control Zone | Avigation Easement | Waiver of Claim | Notification | Required SLR |
|---|---|---|---|---|
| Zone A | Required | Required | Required | N/A (Prohibited) |
| Zone B | Required | Required | Required | N/A (Prohibited) |
| Zone C | Not Required | Required | Required | Specific to Use |
| Zone D | Not Required | Not Required | Required | 25 db |
| Zone E | Not Required | Not Required | Required | Not Required |
Sound Level Reduction (SLR) Design Requirements
The City of Orlando requires that the mandated SLR be achieved through a combination of building design, choice of materials, and execution of construction details [Section 58.382]. No new building or structure requiring an SLR of 25, 30, or 35 may be constructed unless the City of Orlando determines the plans and specifications indicate conformance with these standards [Section 58.382].
The City of Orlando may require a field test by a Qualified Acoustical Consultant to verify the finished building's actual noise reduction. This involves measuring four aircraft fly-over events with a Type II Sound Level Meter both inside and outside the structure [Section 58.382].
Existing Nonconforming Uses
The Orlando AN: Airport Noise Overlay District does not require the retrofitting of existing structures. However, it limits the expansion of nonconforming uses. No existing nonconforming use may be increased in height or enlarged at a cost exceeding 50% of the value of the existing use unless an airport height zoning permit is issued [Section 58.1224]. If a nonconforming use is more than 80% torn down, destroyed, or decayed, the City of Orlando may petition to compel the owner to remove or reconstruct the structure to conform to current noise standards [Section 58.1224].
Sections Cited
- Section 58.371 - Purpose of the District
- Section 58.372 - Establishment of Aircraft Noise/Land Use Control Zones
- Section 58.380 - Land Use Restrictions
- Section 58.381 - Sound Level Requirements for Structures and Buildings
- Section 58.382 - Sound Level Reduction (SLR) Design Requirements
- Section 58.1217 - Airspace Surfaces
- Section 58.1223 - Rules of Interpretation
- Section 58.1224 - Continuance of Existing Nonconforming Use