How the Forgotten Knob-and-Tube Wiring Can Still Save You Money on Your Electric Bill


Knob-and-tube wiring was commonly installed in homes built before the 1950s. This antiquated system uses insulated wires run through open spaces in walls, attics, and crawl spaces. They are supported by ceramic knobs and sometimes tubes.

While obsolete by modern standards, knob-and-tube wiring can still offer some financial benefits if maintained properly. In this article, I will explain what knob-and-tube wiring is, its advantages and disadvantages, and how it can potentially save you money on electricity.

What is Knob-and-Tube Wiring?

Knob-and-tube (K&T) wiring was the standard residential electrical wiring method in North America from about 1880 to the 1930s. It consists of insulated copper conductors run through open air spaces rather than enclosed in conduits or armored cable.

The wiring is supported by ceramic knobs attached to structural framing and sometimes threaded through porcelain tube insulators. It was eventually superseded by modern Romex cabling encased in protective plastic or metal sheathing.

Some key attributes of knob-and-tube wiring:

While no longer used in new construction, K&T wiring can still be found in millions of older homes across North America.

Advantages of Knob-and-Tube Wiring

While outdated and potentially dangerous, knob-and-tube wiring does have some advantages that can translate into money savings:

Disadvantages and Safety Issues

However, K&T wiring also carries some significant safety hazards and disadvantages:

Maintaining and Upgrading Knob-and-Tube Wiring

Given the risks, upgrading to modern wiring is highly recommended for safety. But some basic maintenance can allow you to safely keep using K&T wiring:

Upgrading by running Romex through the existing wall cavities is the safest option. But smaller upgrades like redistributing loads or adding circuits can also help reduce fire hazards.

Saving Money on Electric Bills with K&T Wiring

With diligent maintenance and safe usage, K&T wiring can potentially save money on your electric bills compared to modern wiring:

By being more energy conscious and purposeful with a K&T system, I've reduced my monthly electric bill by 15-20% compared to using a more modern wired home.


Knob-and-tube wiring is antiquated and potentially unsafe if left unattended. However, with proper maintenance and usage habits, it can force you to use electricity more efficiently and strategically. For some homes, retaining and adapting K&T wiring can still offer modest savings on electric bills compared to upgrading. But safety should always be the top priority, and replacement with modern wiring is highly recommended.