If you own an older home in Renton and have heard the term “knob-and-tube,” it’s worth understanding what it means for safety, insurance, and resale. The cost of replacing knob-and-tube wiring depends on the size of your home, how much wiring needs to be replaced, and access. Here’s what local homeowners should know in 2026.
What is knob-and-tube wiring?
Knob-and-tube (K&T) is an early wiring method common in homes built before the 1950s. It has no ground wire, its insulation becomes brittle with age, and it wasn’t designed for modern electrical loads. Many of Renton’s older homes around the Highlands, Kennydale, and Talbot Hill still have some K&T hidden in walls and attics.
Why replace it
- Safety. Aged insulation and the lack of a ground increase fire and shock risk.
- Insurance. Many insurers won’t write or renew a policy on a home with active knob-and-tube.
- Capacity. K&T can’t safely support today’s appliances, EV chargers, or heat pumps.
- Resale. Buyers and inspectors flag K&T, and it can stall a sale.
What a rewire involves
We replace the old wiring with modern grounded circuits, update devices and boxes, and frequently pair the work with an electrical panel upgrade so the whole system is current. Work is permitted and inspected, and we take care to minimize damage to walls and finishes in older Renton homes.
Talk to a licensed Renton electrician
Every home is different, so we assess your wiring and give a free, fixed quote before any work begins. As a licensed, bonded, and insured contractor (WA L&I #LEBROBC755MT), we’ll tell you honestly whether you need a full rewire or a targeted fix. See our Renton electrician page or get in touch to book an assessment.