Plan Circuits and Panel Layout
2-4 hoursDesign circuit layout on floor plan, assign dedicated circuits for kitchen, bathroom, laundry, and HVAC, and plan panel location with adequate working clearance.
Field context
This workflow is part of 5 niche fields
Residential electrical wiring guide with wire gauge sizing, circuit load calculations, breaker panel planning, and code-compliant installation steps.
Design circuit layout on floor plan, assign dedicated circuits for kitchen, bathroom, laundry, and HVAC, and plan panel location with adequate working clearance.
Sum connected loads per circuit, apply demand factors per NEC/IEC, and verify total service capacity is not exceeded.
Select wire gauge for each circuit based on load, breaker size, and run length. Verify voltage drop stays below 3% for branch circuits and 5% total.
Mount boxes at correct heights (outlets 300 mm / 12" above floor, switches 1,070 mm / 42"), secure to studs, and ensure box volume meets fill requirements.
Drill stud bays, pull NM-B (Romex) or conduit, maintain 32 mm (1-1/4") setback from stud face, install nail plates where wires pass through, and label circuits at panel.
Terminate wires at outlets, switches, and fixtures, connect to panel breakers, perform continuity and polarity checks, and schedule electrical inspection.
Calculate total connected load and demand load for service sizing. · Sum wattage per circuit and apply NEC demand factors. · Final load verification before energizing the panel.
Determine number and amperage of circuits needed for the panel schedule. · Match breaker amperage to wire gauge and continuous load requirements. · Verify panel breaker schedule matches installed circuits.
Apply demand factor percentages to connected loads.
Select correct wire gauge based on breaker size and insulation type. · Confirm wire gauge matches planned circuit amperage during pull.
Verify voltage drop is within 3% on branch circuits for long runs. · Re-check voltage drop with actual measured run lengths. · Measure and confirm voltage at farthest outlet under load.
Calculate room area for minimum outlet spacing requirements.
Standard copper wire ampacity for NM-B cable in residential applications.
| Wire Gauge (AWG) | Cross Section (mm²) | Max Breaker (A) | Typical Use |
|---|---|---|---|
| 14 AWG | 2.08 mm² | 15 | Lighting, general outlets |
| 12 AWG | 3.31 mm² | 20 | Kitchen, bathroom, laundry circuits |
| 10 AWG | 5.26 mm² | 30 | Dryer, water heater (240V) |
| 8 AWG | 8.37 mm² | 40 | Range, large HVAC units |
| 6 AWG | 13.3 mm² | 60 | Sub-panel feeder, EV charger |
Create a clear panel directory before pulling wire — label both ends of each cable with circuit number and destination. Future troubleshooting and remodels depend on accurate labeling.
Leave 150 mm (6") of extra wire in each box for device connection and future changes. Pulling wire tight makes connections difficult and violates minimum length requirements.
Keep data, coax, and low-voltage cables at least 300 mm (12") from parallel electrical runs. Cross low-voltage wires perpendicular to line voltage to minimize interference.
Install a panel with 20–30% spare breaker spaces. Running a conduit stub to the attic or basement during rough-in costs little now and saves major work for future circuits.