If your home is 50 years old or more, it’s time to consider rewiring, and the first step is to have the condition of your electric system evaluated by a professional electrician. Signs that you need an electrical upgrade include:

•  Obsolete screw-in fuse electric panel or knob-and-tube wiring.
•  Frequently tripped breakers or fuses.
•  Electrical burning smells.
•  Charred outlets or switches.
•  Cracked, flaking insulation of the visible wiring in attic.

   The electrician will look at the condition of the wiring, receptacles and switches, and also evaluate how adequate the incoming service is for the number of major appliances and other electrical loads. Because most older homes have 60 or 100 amp electric service, which is undersized for today’s power usage, upgrading the electric service to 150 or 200 amps is almost always required.

   “The absolute minimum for a rewire is $6,000, but the average home costs between $10,000 and $17,000,” according Craig Eaton, of Eaton Electric, Gainesville, Florida. “Expect it to cost more for a large house or if the type of construction makes pulling the cables difficult.” Homes with an attic tall enough for an electrician to easily move around or a crawl space under the floor make the work much easier, while concrete block houses with concrete floor slab and a flat roof (no attic) are the most challenging.

   Rewiring is messy and disruptive, requiring holes to be punched in walls in multiple locations, with dust, noise, and construction materials stacked around the house during the work. The best time to do it is during a remodeling project, such as renovating the kitchen or adding a bathroom, when subcontractors will be opening up the walls anyway. And you don’t want to be there while the work is done. “I need to have the house to myself for a minimum of two weeks,” says Craig. “And possibly three.”

   The following photos are examples of the wall damage that will be done, and then repaired at completion of the work.

   And here’s a few tips for planning your rewiring:

1. Do you want to run wiring for data and security while you’re at it? It will less expensive to do everything at once if you need it.
2. Determine whether a partial rewire will be adequate. Ask your electrician to evaluate whether part of the system is still in good condition and can be left in place.
3. Find an electrician that has experience working with older homes. Rewiring is a complex process that involves understanding the structure behind the wallboard and the best ways to run wiring with a minimum of wall damage.
4. Get a written contract detailing exactly the work to done and how any surprises will be handled. There’s always something unexpected when you  open the wall of an old home. Be ready.
5. Pull permits for the work. Your electrician will know the electrical code standards and be able to secure a permit for the work. When everything is  completed, be sure that a final inspection was done and keep a copy of the permit with all inspection signatures and notes. When it comes time to sell your house, many homebuyers now want to see evidence of building permits for all renovations.
6. Make reconstruction and wall repairs a key part of the job. Let your contractor know that cleanup and restoration is important to you and know exactly what level of finish is expected. Do you want the walls repainted at completion, for example?

   Is a rewiring worth the expense and inconvenience? According to our electrician friend Craig, yes it is. “Rewiring is a lot of work, but then you’re good for another 50 years!”

    Also, see our blog post How dangerous is old electrical wiring?

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Here’s links to a collection of our other blog posts about ELECTRICAL WIRING:

• Which house appliances need a dedicated electrical circuit?

• Can a short circuit cause a high electric bill?

• What is the maximum spacing requirement for securing NM-cable (nonmetallic-sheathed cable)?

• Is it alright to just put wire nuts on the end of unused or abandoned NM-cable or wiring?

• What causes copper wires to turn green or black in an electric panel?  

• What are typical aluminum service entrance wire/cable sizes for the electrical service to a house?

• Why is it unsafe to bond neutral and ground wiring at subpanels?

• Should I get a lightning rod system to protect my house?

• Why is a strain relief clamp necessary for the cord connection to some electric appliances?  

• Does a wire nut connection need to be wrapped with electrical tape?

• What is the minimum clearance of overhead electric service drop wires above a house roof?

• What are the requirements for NM-cables entering an electric panel box? 

• What is the color code for NM cable (Romex®) sheathing?

• Why is undersize electric wiring in a house dangerous? 

• What causes flickering or blinking lights in a house?

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• How can I find out the size of the electric service to a house?

• Can old electrical wiring go bad inside a wall? 

• What is an open electrical splice?

• What are the most common electrical defects found in a home inspection? 

• What is the life expectancy of electrical wiring in a house? 

• What is an "open junction box"?  

• What is a ground wire? 

• I heard that aluminum wiring is bad. How do you check for aluminum wiring?  

• What is "knob and tube" wiring?  

• What is the code requirement for receptacle outlets in a closet?

   Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.