ADU Wiring in Oregon: What Every Homeowner Needs to Know

The Growing Demand for ADUs in Western Oregon

Accessory Dwelling Units (ADUs) — also known as in-law suites, backyard cottages, or granny flats — are growing rapidly in popularity across Lane and Douglas Counties. Oregon's progressive ADU-friendly legislation has made it easier than ever for homeowners in Eugene, Springfield, and Cottage Grove to add a rental unit, house family members, or create a dedicated home office. However, powering an ADU correctly requires a completely independent and robust electrical infrastructure.

Why Your Existing Panel Cannot Simply Be Extended

Many homeowners assume they can just run a few extension circuits from their main home panel to power an ADU. This is a dangerous misconception. A fully functional ADU requires independent power for heating, a full kitchen, a water heater, laundry, and potentially an EV charger. This combined load can easily exceed 60 to 100 amps of continuous demand — far more than most existing home panels have available. Attempting to overload your main panel without proper engineering creates a severe fire hazard and will fail building inspections. Explore our dedicated ADU Wiring service details to see how we design safe, independent systems.

Subpanels, Underground Feeders & Permits

The correct approach is to install a dedicated subpanel inside the ADU, fed by a properly sized underground feeder cable from your main service entrance. We perform precise load calculations to determine the correct subpanel size (typically 100 to 125 amps), trench and install weatherproof underground conduit, and wire the entire ADU interior to modern code. We also handle all permit applications and inspections with your local building department, ensuring your project passes on the first review. Our team will also verify your main Electrical Panel has sufficient capacity to feed the new ADU subpanel safely.

For official Oregon ADU building codes and electrical requirements, visit the Oregon Building Codes Division. For premium, industry-leading residential subpanel hardware, we install robust systems manufactured by Eaton.

Ready to power your ADU the right way? Contact the licensed specialists at Checkpoint Electric LLC at (541) 733-7027 to schedule your ADU electrical estimate today.