Generators

Generators can provide emergency power to your home or business in case of power failure.

Do I need a permit for generators?

A building permit is not required for the use of a portable generator only when it is intended to power a few appliances (refrigerator, fan, etc.) and a string of lights that are connected directly to the generator. Portable generators must be stored indoors empty of fuel while not in use and must be placed outdoors while being used, 10 feet away from windows, doors and other openings to prevent exhaust fumes from getting inside the building.

However, if you wish to connect a portable generator to the building's electrical system to power certain circuits, you must secure an electrical permit for the installation of a device that will allow you to do this safely. Refer to the Generator Guidelines below for detailed permit requirements.

To place and keep a generator permanently in an outside location, a building permit is required. Multiple county agencies regulate different aspects of its installation. A permit application must include a set of plans prepared by a design professional. Multiple regulatory agencies will review the application for compliance with all codes and regulations applicable for the generator and its fuel source.

What are the permit requirements?

Refer to the guidelines below for detailed permit requirements for an emergency generator. This information is being provided as a guide to assist with the permitting process for generators. Contact each applicable agency to verify and obtain current information.

These guidelines are for the permanent installation of stand-alone generators to be utilized to power residential or commercial structures during power outages. The generators typically use gasoline, liquid petroleum, natural gas or diesel fuel. These requirements are to be submitted at the time of permit application for properties located within unincorporated Miami-Dade County. If your property is located within a municipality, contact your municipal Building Department.

See below required items for generator permit.
- A completed Building Permit Application(yellow form):
  - Category 38 (Standalone) to be used when there is no building permit and plan review is required
  - A completed Contact Sheet
- Completed electrical fee sheet for category 38 fee code G012.
- Signed, sealed and dated plans prepared by design professional. The electrical plans may be prepared by a licensed contractor. The electrical qualifier’s notarized signature must appear on all electrical pages.
- Site plan indicating location of proposed generator and any associated permanent fuel tank(s) with the distances to existing buildings, and to property lines.
Electrical
- The location of electrical panel and transfer switch must be indicated on site plan.
- Gas pipe bonding must follow National Electrical Code (NEC).
- Plans must show connection between the generator frame and ground rod.
- Provide generator specifications, including connected load, size of conduit, conductors, over current protection devices, switches and generator one-line diagram.
- Identify transfer switching as "not separately derived."
Mechanical
- Identify the location of the generator exhaust with respect to exterior wall openings in the building. The generator exhaust shall be located 10 feet away from wall openings such as windows, doors, exhaust fans, appliance vents, etc., in accordance with the requirements of the Florida Residential Code or for commercial generators see the Florida Mechanical Code.
Plumbing/Gas (for propane and natural gas)
- When the source of fuel is natural gas, indicate the location of natural gas meter on site plan.
- When the source of fuel is propane gas, location of containers shall comply with the minimum separation distances to other containers, buildings, property lines and sources of ignition established by Tables 6.3.1, 6.4.2, 6.4.5.8 and sections 6.3.2 through 6.3.12 of National Fire Protection Association (NFPA) 58.
- Indicate the location of water, sewer, well and interceptors on site plan.
- Gas piping diagram shall include the following information:
  1. Isometric of piping layout
  2. Longest run of gas pipe (from source to farthest outlet)
  3. Pipe size(s)
  4. Appliance(s) BTU output
  5. Type of materials used-gas table used from minimum sizing.
Structural (Generator Pads)
- Nature of soil and allowable soil bearing capacity. Florida Building Code (FBC) Section 1818.1
- Generator pad size, thickness and reinforcement
- Generator anchoring detail
- Polyethylene sheets as vapor barrier beneath ground floor slab for 2” concrete cover. FBC Section 1820.4
- For commercial properties only, one field density test required, to be provided at the time of inspection to verify a minimum of 95% of maximum dry density. FBC Section 1820.3.2 & 1820.3.1
- Check the Generator Structural Information Form for specific instructions.
Get clarification on plan review comments, discuss rework fees or resolve other issues by meeting with Plan Review professionals. You must create an account and register through the online registration system (MeetQ) to meet with staff. Consults can be scheduled in-person, by phone, or virtually on the specified days and times listed on the MeetQ homepage.
Permanent generators fueled by propane gas or natural gas not exceeding five feet in height from finished grade to the top of the generator shall be permitted as an accessory use in certain residential districts and shall meet the following setbacks:
- Front - behind the front building line.
- Rear - 5 feet
- Interior side - 3 feet in RU (Residential) districts, 5 feet in EU (Estate), AU (Agriculture) and GU (Interim) districts
- Side Street - behind the side street building line, unless completely screened from view by a wall or hedge. In no event shall a permanent installed generator be placed closer than 10 feet to the side street property line.
- Spacing - there shall be no spacing requirements between the principal building and the permanently installed generator.
For the location of a commercial generator, refer to Chapter 33-51 of Miami-Dade County Code for minimum setback distances for business and industrial zoning districts, excluding IU-C (refer to 33-273 for IU-C setback requirements). There shall be no spacing requirements between the principal building and the permanently installed generator.

For more information, call the Zoning Information Section at 305-315-2660.
DERM plan review and approval is required for all Aboveground Storage Tanks (ASTs) and Underground Storage Tanks (USTs).

General Requirements
- New UST systems for fuel are required to have double wall construction, overfill prevention, overspill protection, tank interstitial monitoring, continuous automatic leak detection, anchoring, monitoring well network, protection from corrosion, etc. The components of the system must be on the approved state list.
- New AST systems for fuel require; secondary containment (double wall construction or spill containment dike), overfill prevention, overspill protection, tank interstitial monitoring, continuous automatic leak detection, anchoring, etc.
- Generator and fuel supply (excluding gas powered systems) shall be located a minimum of 100 feet from any potable water supply wells.
- Plans must provide a title block to be signed, sealed and dated by a Professional Engineer registered in the State of Florida, and a title block to be signed and dated by a Pollutant System Specialty Contractor (PSSC).
- Additionally, plans must show:
  - A location map, site plan and/or floor plan showing locations of water supply and wastewater systems.
  - Size, design (double walled vs. single walled), material of construction and location (underground vs. above ground) of the fuel tank and type of fuel to power the generator.
  - Fuel piping layout in plan and profile (cross section showing piping running underground or above ground) of the entire piping running, showing all STP, fuel pumps, piping sumps, piping design (i.e., double walled vs. single walled), material, support and slope of the piping.
  - Compliance monitoring well (MW) network and MW detail(s).
  - Fuel tank pad and anchoring details or anti-buoyancy calculations.
  - All electrical/mechanical equipment (including the generator, remote fill ports, top of tank, etc.) must be above the Base Flood Elevation and/or the required lowest floor elevation. Any system with a portion below the required elevations must show that it is resistant to floodwaters, hydrostatic, hydrodynamic and buoyancy forces.
Specific Residential Requirements
- Only UST systems for fuel greater than 300 gallons are required to have double wall construction, overfill prevention, overspill protection, tank interstitial monitoring, continuous automatic leak detection, anchoring, monitoring well network, protection from corrosion, etc. The components of the system must be on the approved state list.
- A Pollutant System Specialty Contractor (PSSC) is only needed to sign and date plans for installation of underground fuel tanks greater than 300 gallons and/or any underground fuel piping.
- The required lowest floor elevation for residential is the Base Flood Elevation or Crown of Road/ County Flood Criteria + eight inches, whichever is highest. For existing homes, the elevation of the generator equipment may be placed to match the existing lowest finished floor.
Specific Commercial Requirements

Within the Northwest Wellfield and West Wellfield Interim Protection Area or within the Basic Wellfield Protection Area (i.e., within the 210 day boundary) of any public utility potable water supply well, any nonresidential land use proposing a generator will be required to utilize a gas (e.g. Natural Gas, LP Gas, etc.) fueled generator or obtain a variance from the Environmental Quality Control Board (EQCB) for the use, storage and handling of a hazardous material (e.g. Gasoline, Diesel Fuel, etc.).
- Any generator systems with fuel tanks greater than 550 gallons must provide a completed Florida Department of Environmental Protection (FDEP) Storage Tank Registration Form and a Spill Prevention and Response Plan (SPRP) signed and notarized by the responsible party.
- The required lowest floor elevation for commercial is the Base Flood Elevation or Crown of Road/County Flood Criteria + four inches, whichever is highest. Public Works Department When the generator’s proposed location is within an easement, the Public Works Department reviews the application for compliance with Standard Detail G 2.2. Generator pads are treated the same as FPL transformer pads.
For more information, call DERM at 305-315-2800 or email [email protected].
Required for generators installed on commercial properties.
- Plans must be provided with details to indicate compliance with NFPA 110 (2002 Edition)
- Clearly identify the Class, Type and Level of the generator in accordance with NFPA110 Chapter 4.
- Clearly identify the location of the remote annunciator.
- Clearly identify the location of the emergency shut-off controls required by NFPA 110 (5.6.5.6).
- Identify physical protection of the fuel containers and generator when located in areas subject to vehicular traffic.
- Plans must be provided with details to indicate compliance of the fuel system, and/or fuel storage system to be used NFPA30 (2000 edition), NFPA37 (1998), NFPA54 (2002) or NFPA58 (2002).
For more information, call Fire Rescue at 305-315-2771 or 305-315-2785.