| Homeowners

If I sell my house, will my knob and tube wiring affect my sale? It’s a common question we come across as Toronto realtors. In fact, we’re always running into homes that have knob and tube wiring. Whether it’s in one outlet or the majority of the house, disconnected or live, when selling a home or buying houses for sale in Toronto, finding this type of older wiring is common! We’re here to debunk some myths and make the words ‘knob and tube’ a little less scary for you!

Toronto Area Housing Market: What You Need To Know About Knob & Tube

Knob and tube wiring was the electrical system that was used from the 1900 through to the 1950’s. It consists of two wires, live and neutral (no ground). Insulator knobs kept the wires isolated and ceramic tubes were used to line the holes through the wooden joists or studs.

What Makes It So Scary?

Insurance companies have deemed this style of wiring to be unsafe and a fire hazard because if it was installed poorly or has been damaged there’s a greater chance that the wires will short circuit and overheat. However, according to the Electrical Safety Authority (ESA), knob and tube wiring can be safe and functional. In fact, in many ways it’s not that inferior to modern wiring.

Know and Tube Wiring and Insurance

Unfortunately, when buying a home in Toronto, most insurance companies will not give you insurance if your new home contains knob and tube wiring. However, there are companies who will still provide this insurance if the amount of the knob and tube wiring is under a certain percentage, although they’re harder to find. Just make sure that you contact your insurance company to ensure that they’ll cover you before firming up on any purchase agreement.

How Much Does It Cost To Replace Knob & Tube?

You should anticipate paying $800 to $1,000 per room to remove knob and tube.

Myths vs Facts About Knob & Tube Wiring

Here are some of the main myths and facts from the ESA about knob and tube wiring:


  • Knob and tube is an unsafe type of wiring
  • The Ontario Electrical Safety Code no longer recognizes knob and tube wiring as an acceptable wiring method
  • All knob and tube must be disconnected and replaced


  • Knob and tube wiring is safe, provided it is properly maintained by a competent licensed electrician
  • The ESA as well as the Ontario Electrical Safety Code recognize and accept knob and tube wiring methods
  • The Ontario Electrical Safety Code edition contains rules that govern the installation of open type wiring methods (knob and tube). Rules 12-200 to 12-224 set out the minimum safety standards for the installation of open wiring, which may still be installed to this day.

So, there you have it. Your simple guide to knob and tube wiring in Toronto homes. When you buy or sell property in Toronto every detail counts. If you’re looking for a team of Toronto realtors to help you make smart decisions to protect your investment, the Christine Cowern Team’s got you covered. Give us a call at 416.291.7372 or email us at hello@christinecowern.com. We’d love to work with you!