Commercial Electrical for Small Businesses: A Wisconsin Owner's Guide

Commercial electrical work is fundamentally different from residential — different code requirements, higher amp services, and more rigorous inspections.

Commercial vs. Residential Electrical: Key Differences

• Commercial buildings often need 400–600+ amp three-phase service
• Commercial code often requires conduit (EMT or rigid) rather than romex
• Follows NEC plus Wisconsin Commercial Building Code
• More rigorous inspection processes

When You Need New Commercial Electrical Service

• Opening a restaurant, salon, or food service business
• Adding manufacturing equipment
• Converting residential property to commercial use
• Adding EV fleet charging

Tenant Improvements and Build-Outs

Your build-out requires a licensed commercial electrician for all electrical work. The landlord's existing service may need upgrading depending on your equipment — negotiate this in the lease.

Code by Business Type

Restaurants: Commercial-grade GFCI, hood circuits, walk-in cooler circuits, significant amperage for cooking equipment.

Salons: GFCI at all wet locations, dedicated circuits for dryers.

Offices: Data and power infrastructure, surge protection, emergency lighting.

Get a Commercial Estimate

Sparks handles commercial projects of all sizes in SW Wisconsin. Submit your project online or call (608) 790-1334.