Bathroom Electrical Rough-In
Install all electrical wiring, circuits, and boxes before walls are closed. This critical phase ensures safe, code-compliant power for outlets, lighting, exhaust fans, and heated floors.
Why Electrical Rough-In Matters
Electrical rough-in is one of the most critical phases of your bathroom remodel. This is when all wiring infrastructure gets installed behind walls and above ceilings - work that becomes inaccessible once drywall goes up. Getting it right means safe, reliable power for decades. Getting it wrong can mean failed inspections, costly tear-outs, or dangerous fire and electrocution hazards.
Bathrooms have some of the strictest electrical codes in residential construction. The combination of water, electricity, and bare skin creates serious safety risks that building codes address through requirements for GFCI protection, dedicated circuits, proper grounding, and specific outlet placement. Your electrician must understand and follow these requirements precisely.
This phase happens after plumbing rough-in but before waterproofing. Coordination between your electrician and plumber is essential - they need to work around each other's infrastructure without conflicts. The electrical rough-in must be complete and inspected before any insulation, cement board, or waterproofing can begin.
What Happens During Electrical Rough-In
Running New Circuits
Your electrician will run new electrical circuits from your main panel to the bathroom. Most bathroom remodels require at least 2-3 dedicated circuits:
- •20-amp receptacle circuit: Dedicated to bathroom outlets only (code requirement)
- •Lighting circuit: Can be 15-amp, may be shared with exhaust fan
- •Heated floor circuit: Dedicated circuit based on heating system wattage
- •Whirlpool/jetted tub: May require dedicated 20-amp GFCI circuit
GFCI Outlet Placement
All bathroom outlets require GFCI (Ground Fault Circuit Interrupter) protection. These life-saving devices detect electrical current leaking to ground and cut power in milliseconds - essential in wet environments where electrocution risk is highest.
Outlet Placement Requirements:
- • At least one outlet within 3 feet of each sink basin edge
- • Outlets at countertop height: 42-44 inches from finished floor
- • No outlets within 3 feet of bathtub or shower (inside wet zone)
- • Consider outlets for electric toothbrushes, razors, hair tools
GFCI protection can be provided by GFCI outlets, a GFCI breaker at the panel, or by daisy-chaining from a GFCI outlet elsewhere. Your electrician will determine the best approach.
Exhaust Fan Wiring
Bathroom exhaust fans are required by code to remove moisture and prevent mold growth. The electrical rough-in includes running power to the fan location and installing the appropriate switch control.
Fan Options:
- • Fan only (basic ventilation)
- • Fan + light combination
- • Fan + light + heater
- • Fan + light + Bluetooth speaker
Switch Options:
- • Standard on/off switch
- • Timer switch (runs 5-60 min)
- • Humidity sensor (auto operation)
- • Motion sensor activation
Lighting Circuit Installation
Modern bathroom lighting typically includes multiple fixtures for different purposes. During rough-in, your electrician will run wiring to each light location and install boxes sized appropriately for the fixtures you've selected.
- •Vanity lighting: Mounted above or on sides of mirror, typically at 75-80 inches height
- •Recessed/ceiling lights: General illumination, often with dimmer control
- •Shower lighting: Must be wet-rated fixtures, typically recessed
- •Night lights: Low-level lighting for nighttime navigation
Important: Fixtures installed over tubs or inside showers must be rated for wet locations. Standard fixtures are only suitable for dry or damp locations.
Heated Floor Wiring
Radiant floor heating is a popular bathroom upgrade. The electrical rough-in phase includes running the dedicated circuit and installing the thermostat box. The actual heating cable or mat is typically installed later, during the flooring phase.
Circuit Requirements:
- • Dedicated circuit (not shared)
- • 15-20 amp based on floor size
- • 120V for most residential systems
- • GFCI protection required
Thermostat Placement:
- • Near bathroom entrance
- • 60 inches from floor typical
- • Away from heat sources
- • Double-gang box for most units
Confirm your heated floor system specifications with your electrician before rough-in. Different manufacturers have different wiring requirements and thermostat compatibility.
Vanity Light Positioning
Proper vanity light placement is crucial for functional task lighting. The electrical box position must account for mirror size, vanity height, and fixture dimensions.
Optimal Vanity Light Heights:
- Above mirror: Center of fixture at 75-80 inches from floor
- Side sconces: Center at eye level, approximately 60-65 inches
- Mirror width: Light fixture should be at least as wide as mirror
Know your mirror dimensions and vanity light fixture specifications before rough-in. Moving electrical boxes after drywall is installed is expensive and time-consuming.
Bathroom Electrical Code Requirements
The National Electrical Code (NEC) has specific requirements for bathroom electrical systems. Your electrician must follow these codes, and inspectors will verify compliance.
Circuit Requirements
Placement Requirements
Code Compliance is Non-Negotiable: Electrical work that doesn't meet code will fail inspection, requiring tear-out and redo. Worse, non-compliant work creates fire and electrocution hazards that can harm your family. Always hire licensed professionals and pull proper permits.
Circuit Requirements by Fixture
| Fixture/Load | Circuit Size | Wire Gauge | Special Requirements |
|---|---|---|---|
| Bathroom Outlets | 20 Amp | 12 AWG | GFCI, dedicated circuit |
| General Lighting | 15 Amp | 14 AWG | Can share with other lighting |
| Exhaust Fan | 15-20 Amp | 14 or 12 AWG | Often combined with lighting |
| Heated Floor (small) | 15 Amp | 14 AWG | GFCI, dedicated circuit |
| Heated Floor (large) | 20 Amp | 12 AWG | GFCI, dedicated circuit |
| Whirlpool/Jetted Tub | 20 Amp | 12 AWG | GFCI, dedicated, accessible disconnect |
| Towel Warmer | 15-20 Amp | 14 or 12 AWG | Hardwired or plug-in available |
Working with Your Electrician
Clear communication with your electrician ensures the rough-in meets your needs. Here's how to prepare and what to discuss before work begins.
Provide Final Floor Plan
Share your bathroom layout showing vanity, toilet, tub/shower, and any built-ins. Mark where you want outlets, switches, and light fixtures.
Share Fixture Specifications
Provide spec sheets for your vanity lights, mirror, exhaust fan, heated floor system, and any specialty fixtures. Box placement depends on these dimensions.
Discuss Switch Preferences
Decide on dimmer switches, timer switches for the exhaust fan, 3-way switching for large bathrooms, and smart home integration if desired.
Walk the Space Together
Before rough-in begins, walk through the bathroom with your electrician. Verify outlet heights, switch locations, and fixture positions on-site.
Plan for Future Needs
Consider adding extra outlet capacity or conduit for future upgrades. It's much cheaper to add during rough-in than after walls are closed.
Preparing for Electrical Inspection
The electrical rough-in inspection happens before any insulation or drywall is installed. The inspector must be able to see all wiring, boxes, and connections.
What Inspectors Check:
- ✓Correct wire gauge for circuit amperage
- ✓Proper cable securing (staples every 4.5 ft)
- ✓Box fill calculations (not overcrowded)
- ✓Nail plates where cables are close to stud edge
- ✓GFCI protection for bathroom circuits
- ✓Dedicated 20-amp circuit for outlets
Common Inspection Failures:
- ✗Missing nail plates on vulnerable cables
- ✗Improper cable stapling or support
- ✗Wrong wire size for breaker amperage
- ✗Boxes not flush with future drywall surface
- ✗Missing GFCI protection
- ✗Bathroom outlets sharing circuit with other rooms
Pro Tip: Take photos of all wiring before inspection and before closing walls. These photos are invaluable for future repairs or modifications, showing exactly where cables run inside walls.
Frequently Asked Questions
Do bathroom outlets require GFCI protection?▼
Yes, all bathroom receptacles must have GFCI (Ground Fault Circuit Interrupter) protection per NEC code. This can be achieved through GFCI outlets, a GFCI breaker at the panel, or by feeding from a GFCI outlet in another location. GFCI protection detects ground faults and cuts power in milliseconds, preventing electrocution in wet environments. This requirement applies to all outlets within the bathroom, not just those near the sink.
How many electrical circuits does a bathroom need?▼
A typical bathroom remodel requires 2-4 dedicated circuits: one 20-amp circuit for receptacles (GFCI protected), one circuit for lighting (can be 15-amp), one for the exhaust fan (often combined with lighting), and optionally a dedicated circuit for heated floors or a large whirlpool tub. The NEC requires at least one 20-amp circuit for bathroom receptacles, and this circuit cannot supply outlets in other rooms. Larger master bathrooms with multiple fixtures may need additional circuits.
Where should vanity light switches be placed?▼
Vanity light switches should be placed at the bathroom entry point, typically on the latch side of the door at 44-48 inches from the finished floor to the center of the switch box. If you have multiple light zones (vanity, overhead, shower), consider grouping switches together in a multi-gang box. For large bathrooms with two entry points, use 3-way switches for control from either location. Some homeowners prefer dimmer switches for vanity lights to adjust brightness for different tasks.
What size exhaust fan do I need for my bathroom?▼
Exhaust fan CFM (cubic feet per minute) should match your bathroom size: minimum 1 CFM per square foot for bathrooms up to 100 sq ft. For bathrooms over 100 sq ft, add 50 CFM for each toilet, shower, or bathtub. A 50-80 CFM fan suits most standard bathrooms (5x8 to 8x10). Master bathrooms typically need 100-150 CFM. Consider fans with humidity sensors for automatic operation. For quieter operation, choose fans rated at 1.0 sone or less.
Can I install bathroom electrical wiring myself?▼
While some jurisdictions allow homeowners to do their own electrical work with proper permits, bathroom electrical work is complex and safety-critical. Mistakes can cause electrocution, fires, or failed inspections. Most homeowners should hire a licensed electrician, especially for panel work, GFCI circuits, and heated floor installations. If you have electrical experience and your jurisdiction allows it, you might run cables and install boxes while leaving panel connections and final hookups to a professional. Always pull permits and schedule inspections regardless of who does the work.
Electrical Rough-In Checklist
Before Rough-In:
- Electrical permit pulled and posted
- Final bathroom layout approved
- All fixture specifications provided to electrician
- Vanity, mirror, and light dimensions confirmed
- Heated floor system selected (if applicable)
- Switch preferences decided (dimmers, timers, smart)
After Rough-In:
- All boxes installed at correct heights
- Dedicated 20-amp bathroom circuit installed
- GFCI protection in place
- Exhaust fan wiring complete with switch
- Heated floor circuit and thermostat box ready
- All cables properly secured and protected
- Photos taken of all wiring locations
- Electrical inspection scheduled