Electrical Wiring and You: Why You Must Absolutely Understand the Wiring in Your House

It should come as no big surprise to you that electrical wiring plays a big role in the function of your house. If you have an outdated power supply, you’ll find yourself tripping breakers or fuses when you try to turn on the TV and blow dry your hair at the same time. Same thing for running a dishwasher and a clothes dryer. Without ample power supply for your house, you’ll be constantly resetting breakers or worrying about how much power you are using at any one point. Safety is an even bigger concern than inconvenience.  Outdated, improperly installed or neglected wiring can lead to fires or other electricity concerns. Needless to say, the wiring behind your walls is important!! When it comes to updating old systems, you are looking at an expensive bid as there is a lot of work involved in re-wiring the house. Starting with knocking holes in the walls, switching out the old system, installing a new breaker box, working with your local utility company and the cost for materials this job can easily run to $5,000 – $10,000+ depending on the size and configuration of your property. As always, being  informed is key when you go to buy or sell a house, and knowledge of the electrical system is no different. Let’s dig into the different types of electrical systems you’ll find in houses.

Knob & Tube:

knob and tube, k&t

Example of Knob and Tube Wiring

Knob and tube systems are some of the oldest wiring systems in the world. They started becoming prevalent in the 1880s and were a popular system until post-WWII. Sometimes abbreviated K&T, this was the original standard when it came to electrical wiring. As with many things invented in the 19th Century, we’ve come up with replacements for the old technology, but you will be surprised how often you find knob and tube wiring in homes today. I’m currently working on a project where the house was built in 1921. Guess what I found? Yup! Good ol’ knob and tube wiring throughout the entire house. Once I saw that, I knew I’d be spending a few thousand dollars bringing that system up to modern code compliance. If you are doing substantial work on a house with knob and tube wiring, be prepared for the city to tell you that you need to replace the wiring due to fire concerns. Additionally, knob and tube wiring does not provide a grounding wire for safe discharge of electricity. I won’t get into the details here, but having a ground wire is essential for safety. Besides all the safety hazards, these systems can’t handle the power requirements from modern appliances and electronics. Be prepared to upgrade this system anytime you see it!


Aluminum wiring was popular in the US during the 60s and 70s when copper prices rose to extremely high levels. While you won’t come across aluminum wiring in residential construction too much, you’ll still find it’s used today by utility companies for power transmission. Aluminum wiring, even more so than knob and tube systems, poses a big safety risk to the residents. The crux of the problem lies with improper installations of the wiring. There are two ways you can fix this problem. The simple solution is to complete switch out all the aluminum wiring for modern copper. Another option is “pigtailing” the aluminum wire to new copper wires. This decision is best left up to a licensed electrician and is definitely not recommended for the weekend handyman. I’ve also heard of certain cases where insurance companies either charge a higher premium for houses with aluminum wiring or deny coverage all together. Any way you slice it, leaving aluminum wiring alone is just asking for trouble.

Non-Metallic Sheathed Cable (AKA Romex)

romex wiring, residential wiring, electrical

Example of Romex Wiring

Now we finally come to the most modern and safest electrical system for your house. You’ll rarely hear an electrician talk about non-metallic sheathed cables. Instead you’ll hear it referred to by it’s trademarked name: Romex. Much like Kleenex or Frisbee, Romex is actually a brand of electrical wiring developed by the Southwire Company. Romex is what you’ll find in all new construction homes as well as any home that I renovate. It’s the safest, easiest to install and all wires are color coded depending on their use. This is the stuff you want in your house, no bones about it. If it’s not in yours, the value of your property could suffer.


I hope after reading this short primer, you have a better understanding of the types of wiring found in houses. It’s not just a “nice to know” item, this is something that is absolutely mandatory for every homeowner, seller or prospective buyer. Not only is it a matter of costly upgrades and inconveniences, it can also be the difference between having a safe home or one that is prone to fire. As always, feel free to reach out via email or a phone call if you have any questions about electrical systems in your house or if you need a good contractor to evaluate your wiring.