How to Safely Replace Knob and Tube Wiring in your Historic Home

How to Safely Replace Knob and Tube Wiring in your Historic Home


Replacing knob and tube wiring in historic homes can be daunting, but with proper planning and precautions, it can be done safely. As the owner of a historic home, I want to upgrade to modern electrical systems without compromising the structure's integrity or historic charm. This article provides a step-by-step guide to help homeowners like myself tackle knob and tube wiring replacement in a safe and effective manner.

Dangers of Knob and Tube Wiring

Knob and tube wiring was commonly installed in homes built before the 1940s. It features insulated wires running through ceramic knobs and flexible tubes. While sufficient for earlier electrical loads, knob and tube wiring poses several safety risks:

It is crucial to replace knob and tube wiring to protect your family and home. Let's look at how to do this safely.

Planning Your Knob and Tube Replacement Project

Careful planning is key to tackling wiring replacement in a historic home. Here are some steps to plan out the project:

Consult an Electrician

Consult a licensed electrician experienced in historic homes. They can:

Develop a Budget

Factor in costs for the electrician's labor, new electrical boxes, wiring, conduit, and materials needed to patch up walls and ceilings after installation. Knob and tube replacement can cost $2,000 to $15,000 or more depending on your home's size and complexity. Build in contingencies for potential hidden issues.

Research Local Building Codes

Local building codes, especially for historic homes, can impact your plans. Research permit needs, allowable materials, and any special restrictions ahead of time.

Prepare Your Home for the Project

To enable safe access for wiring replacement:

Take time to carefully plan every aspect of the project upfront.

Safely Replacing Knob and Tube Wiring

Once planning is complete, you can move on to safely removing old wiring and installing new wiring. Here are best practices:

Remove Old Knob and Tube Wiring

Install New Wiring System

Restore Surfaces

By methodically replacing old wiring and thoughtfully restoring surfaces, you can modernize your electrical system while retaining your home's historic look and feel.

Safety Precautions During Wiring Replacement

Your safety should remain top priority throughout the knob and tube replacement process:

Staying safe requires vigilance, preparation, and due caution throughout the wiring replacement process.

Preserving Historic Character While Upgrading Systems

For historic homes, maintaining the structure's original character is often a priority during renovations. Here are tips to upgrade wiring while preserving historic architectural integrity:

With careful planning and execution, crucial electrical upgrades can be accomplished while still preserving your home's treasured historic features.


Replacing outdated and dangerous knob and tube wiring in historic homes requires extensive planning, specialized skills, safety precautions, and a considerate approach. While it represents a major undertaking, modernizing your electrical system will provide invaluable peace of mind and protect the value of your investment. Pay particular attention to working safely and limiting disturbances to historic finishes. With the right electrician and precautions, you can complete knob and tube replacement properly. Your home will reap significant safety benefits while retaining its irreplaceable historic charm.