How to Rewire a House

Wires sticking out of a hole in the wall.
  • 80 hours
  • Advanced
  • 800
What You'll Need
Wires and cables
Cutting tools
Wire cutter
Wire connectors
Junction boxes
Safety eye wear
Ladder (to reach high spots)

Whether you’re flipping an investment or restoring your dream home, there may come a time where you find yourself rewiring a house. Since working with electricity is potentially dangerous, you should have a basic understanding of how electricity works and the steps required to stay safe during the process. With that in mind, doing your own rewiring can save you a substantial amount of money. Here are some pointers to help you get your house rewired safely.

Step 1 - Take Precautions

Before you start working on the rewiring task or any other electric-based project, always take precautions for your safety. Use tools with rubber-insulated handles to absorb shock and invest in a reliable current tester. Wear appropriate clothing and eye protection and use caution when working on ladders or in rafters.

Always turn off the electric power before starting work. You can turn off the power from the main switch in the circuit panel or just turn off the electrical loop that you’re working on, but always use the current tester to make sure the line is dead before starting work.

Step 2 - Plan

A man looks at a breaker box.

Investigate your current lighting and outlets and evaluate your usage. Will you need to add an outlet or include additional light fixtures? Also take this opportunity to make updates to the wiring, such as running an exclusive line from the electrical box to major appliances, replacing the electrical box if needed, and upgrading the cable. If you want to run any other cables or wires, this is a good time to incorporate that work in too. Map out a new design to use as a blueprint, but make sure any additions fit within the county code and find out about needed permits.

Step 3 - Remove Old Wires

Even if you’re rewiring the entire house yourself, it’s a good idea to have a certified electrician take a look at your current wiring. Just because the system is old, doesn’t mean it all needs to be replaced. Before you spend the time and money to rewire every section, have a professional test it for you and identify the problem areas. You may find it difficult to remove all the old wiring because the wiring is attached to the joists or wallboards will be in the way. It’s okay to cut the wire at both ends and run new wire without pulling out all of the old wire.

Step 4 - Install New Wires

Someone wires an outlet.

Unless your home is already gutted as a result of a major renovation, you probably don’t want to remove every piece of sheetrock. Instead, route your wiring through the attic or crawlspace. Use extreme caution when drilling any holes through cross beams or walls so that you don’t hit existing electrical lines, unexposed brick walls, or plumbing pipes. Add any lines that will split off to additional outlets or fixtures by installing a junction box mounted to a joist.

Feed wires through walls and down to outlets. It’s helpful to have a second person on the receiving end. Staple wiring to nearby joists where you can access it. Attach the new wires to electrical outlets in the proper locations. For light fixtures, match up the wires, including the ground wire, and use electrical tape to wind the wires together before capping them.

Step 5 - Work On the Breaker Box

Make sure you have enough wire when you work on the breaker box. Double-check all circuits to ensure you are connecting them to the correct breaker. Always label your breakers immediately. Once your wiring is complete from the outlet to the breaker box, test your system and call in the inspector before covering up access points.