Knob and tube wiring was commonly installed in homes built before the 1950s. While it was suitable for the electrical needs at the time, this old wiring system is inefficient and potentially hazardous by today's standards. Rewiring a home with knob and tube wiring can be a major project, but it is worthwhile to bring the electrical system up to code and add safety and convenience. Here is an in-depth guide on how I rewired my own home to replace the obsolete knob and tube wiring.

Dangers of Knob and Tube Wiring

Knob and tube wiring consists of insulated wires run through open air, supported by ceramic knobs and tubes. It lacks grounding and sufficient wire gauge for higher electrical loads. There are several risks posed by this outdated wiring:

I wanted to feel safe and have full modern electrical capacity in my 70 year old home. Replacing the obsolete knob and tube wiring with new grounded NM cable was essential.

Evaluating Your Electrical Needs

Before deciding on rewiring, consider the age of your home's electrical system and what additional capacity you need.

For a 1930s small 2 bedroom home like mine, rewiring made sense to support higher wattage modern appliances. I budgeted for 200 amp electrical service and grounded wiring throughout.

Hiring an Electrical Contractor

Electrical work carries risk of injury or fire if done incorrectly. I strongly recommend hiring a licensed electrician for any major rewiring project. Here are some tips for finding the right pro:

I selected a well regarded local electrical company that informed me throughout the project. Their expertise was essential.

Rewiring Step-By-Step Process

With an electrician hired, we systematically rewired my home circuit by circuit:

1. Shut Off Power and Remove Old Wiring

2. Route and Install New Wiring

3. Connect to New Electrical Panel

Over 6 weeks, the house was systematically rewired to modern electrical code. It went smoothly thanks to an experienced electrician.

Common Rewiring Challenges

Rewiring a house as old as mine always involves surprises and challenges. Here are some we encountered and how we solved them:

Careful planning and an adaptable electrician allowed us to work around all issues. I assisted to keep labor costs down while ensuring quality.

Costs of Replacing Knob and Tube Wiring

Rewiring a whole house is a major investment that pays off in safety. Here are the typical costs:

In total, a full rewire like mine costs $8,000 to $15,000 on average. Regional rates vary. Check with local electricians.

While not cheap, the peace of mind and full functionality is worthwhile. Shop around for competitive pricing from qualified electricians.

Is a Rewire Required by Code?

Many wonder if removing knob and tube wiring is strictly required. Here are the facts:

I recommend consulting your local building department for rewiring requirements in your area. Most agree it should be done but timelines vary.


While rewiring a house is a major undertaking, safety risks and limitations of knob and tube wiring make it an essential upgrade. By hiring a professional electrician and budgeting appropriately, you can completely replace obsolete wiring for a safer, more functional home electrical system. It provides great peace of mind eliminating the risks of old wiring. I am thrilled to finally have a modern, grounded electrical system after rewiring my house.