Outdoor Electrical: Lighting, Outlets, and Code Requirements in Wisconsin

The Quick Answer

Outdoor electrical work in Wisconsin must withstand extreme weather — from sub-zero winters to humid summers — while meeting strict code requirements for wet and damp locations. All outdoor outlets require GFCI protection and weatherproof covers, underground wiring must be buried to code depth, and landscape lighting installations must use outdoor-rated materials and proper wiring methods. Most outdoor electrical work requires a permit.

Outdoor Outlet Requirements

GFCI Protection — Non-Negotiable

Every outdoor outlet must have Ground Fault Circuit Interrupter (GFCI) protection. GFCIs detect when current is flowing through an unintended path — like through water or a person — and shut off power in milliseconds.

All outdoor receptacles: Must be GFCI-protected, regardless of whether they're covered or exposed
Options: GFCI outlet at the location, or GFCI breaker in the panel protecting the circuit
Testing: Press the TEST button monthly to verify the GFCI trips, then press RESET
Cold weather note: GFCI outlets can trip more frequently in extreme cold — this is normal and indicates they're functioning correctly

Weatherproof Covers

Wisconsin code follows NEC requirements for outdoor outlet covers:

In-use covers (bubble covers): Required for outlets that may have something plugged in while the cover is closed — such as holiday lighting or block heater receptacles
Standard weatherproof covers: Acceptable only for outlets where nothing will be plugged in while the cover is closed
Wet locations vs. damp locations: Outlets directly exposed to weather require wet-location rated covers; outlets under covered porches may qualify as damp locations with slightly different requirements

Placement Requirements

Wisconsin follows NEC requirements for outdoor outlet placement:

Front and back: At least one outdoor outlet at the front and one at the rear of the home (for new construction)
Height: Outdoor outlets should be mounted at a height that minimizes exposure to snow accumulation and splashing
Accessibility: Outlets must be readily accessible without climbing or moving obstacles

Landscape Lighting

Low-Voltage Landscape Lighting

Most residential landscape lighting uses low-voltage (12V) systems:

Transformer: Steps down 120V household power to 12V — installed near an outdoor GFCI outlet
Wire: Low-voltage landscape wire (typically 12 or 14 gauge) buried 3-6 inches deep
Advantages: Safer to install and maintain, lower operating cost, easy to reconfigure
Considerations: Voltage drop on long runs — plan wire gauge and transformer location carefully

Line-Voltage Landscape Lighting (120V)

Used for larger fixtures, security lighting, and post lights:

Burial depth: UF (underground feeder) cable must be buried at least 12 inches deep in Wisconsin (24 inches under driveways or parking areas)
Conduit option: Using PVC conduit allows shallower burial (6 inches minimum) and easier future modifications
GFCI protection: Required for all outdoor 120V circuits
Permit required: Line-voltage outdoor circuits require an electrical permit in Wisconsin

LED vs. Traditional Landscape Lighting

LED advantages: 80% less energy, 25,000+ hour lifespan, minimal heat, available in multiple color temperatures
Transformer sizing: LED fixtures draw far less power — a transformer that handled 10 halogen fixtures can power 40+ LED fixtures
Color temperature: 2700K (warm white) is most popular for residential landscapes; 3000K for a slightly brighter, modern look

Outdoor Electrical Projects

Deck and Patio Lighting

Recessed deck lights in steps and railings (low-voltage, typically)
String light circuits — dedicated outlet with timer or smart switch control
Post cap lights for deck railings
Under-bench or under-railing LED strips

Security and Motion Lighting

Motion-activated floodlights at entry points and dark areas
Dusk-to-dawn fixtures for continuous illumination
Smart outdoor lights with camera integration
Placement: 8-10 feet high for motion sensors, angled to avoid false triggers from pets and traffic

Outdoor Kitchen and Entertainment Areas

Dedicated circuit: Outdoor kitchens need dedicated 20-amp GFCI circuits for refrigerators, grills, and other appliances
Outlet placement: Countertop outlets every 4 feet (matching kitchen code) with in-use weatherproof covers
Overhead lighting: Weatherproof pendant or recessed fixtures rated for wet locations
Ceiling fans: Must be rated for damp or wet locations depending on exposure

Detached Structures

Running power to sheds, detached garages, workshops, or pool houses:

Underground feeder: Must be properly sized for the load and buried to code depth
Subpanel: Larger structures may need their own subpanel with a disconnect
Separate grounding: Detached structures require their own grounding electrode system
Permit required: Always required for new circuits to detached structures

Wisconsin Winter Considerations

Block heater outlets: Many Wisconsin homeowners need weatherproof outlets for engine block heaters — install with in-use covers and GFCI protection
Snow and ice loads: Exterior fixtures must be rated for the weight of snow and ice accumulation
Heat tape circuits: Roof and gutter heat tape prevents ice dams but requires a dedicated circuit with GFCI protection
Holiday lighting: Plan dedicated circuits for holiday displays to avoid overloading existing outdoor outlets
Freeze protection: Outdoor outlet boxes should be sealed against moisture infiltration that freezes and damages components

Code and Permit Requirements

In Wisconsin under SPS 316:

Most outdoor electrical work beyond replacing a fixture requires a permit
All outdoor wiring must use weather-appropriate materials (UF cable, weatherproof boxes, wet-location rated fixtures)
Underground installations must be inspected before backfilling
GFCI protection is mandatory for all outdoor receptacles and circuits
Work near pools, hot tubs, and fountains has additional clearance and bonding requirements

Plan Your Outdoor Electrical Project

Outdoor electrical work requires weather-appropriate materials, proper burial depths, and code-compliant installation. Call Couillard Electric at (262) 618-2851 for a free estimate on your outdoor electrical project.

Serving Sheboygan, Mequon, Port Washington, Grafton, Cedarburg, West Bend, Plymouth, Kohler, and surrounding Wisconsin communities.