One of the first things you need to consider when you are planning a home renovation is the existing electrical system. Is the condition of the existing electrical wiring and the capacity (in amps) of the system up to code? Along with plumbing and heating and cooling systems, updating the electrical system in a house will be one of the most expensive remodeling tasks. Major electrical rewiring will require you to use the services of a licensed electrician. There are situations where you can do some of the electrical work yourself with a proper permit having your work certified by a licensed electrical inspector. You need to check your local building codes before you begin.
Electrical System Components
There are a few main components of a residential electrical system. The service entrance and the main circuit panel are the most important elements of the system. Depending on the complexity of the wiring circuits, additional auxiliary circuit panels may be required. The current National Electrical Code recommends a minimum 100 amp incoming electrical service. If your service panel provides less, it should be upgraded to the minimum or higher amperage to meet the needs of modern electrical loads. Most new homes are wired with 200 amp service. Many times the old service panels do not provide adequate grounding, so if you are keeping your existing panel it should be thoroughly checked out by an electrician.
Aluminum vs. Copper Wiring
The actual electrical wire running through your home that makes up each circuit can be aluminum or copper. Older homes and some homes constructed during the 70′s and early 80′s used aluminum wiring. Modern building codes in most communities do not allow aluminum wiring to be used. There are a number of reasons for this. Aluminum and copper both expand and contract when heated. Aluminum, unlike copper, has a tendency to lose some tightness with each cycle. It can invite corrosion when contacting certain types of metal and this corrosion will increase the resistance of the connection. Fire hazard is the main concern with aluminum.
There are ways to make aluminum safe, but we will cover that in another article. Solid copper wiring is the material of choice for new homes or renovations. Although 14-gage wire is allowed for many circuits, it’s recommended you install 12-gage wiring, which costs a little more but can handle more electrical current, making it safer and more energy-efficient.
If you are renovating a very old home and the wiring has cloth insulation or if the insulation is brittle and cracked, you will need to completely replace it with new copper wiring. This requires removing wall covering material down to the studs. It’s a big job. You should get estimates from a reputable electrical contractor. Most older homes have a very limited number of outlets in each room. Be sure to take the time to plan for any new outlets you will want with their corresponding wiring at this time. Once the wiring is in place you can complete the rebuild yourself if you feel you have the required skills.
If you are satisfied with the size of the system, the number of outlets, switches and circuits, (make sure you are happy with the 240 volt outlet number and locations, if any) then you won’t have to add any new circuits to the electrical system. You will just need to update and replace components of the system. Turn off the main breaker switch before doing any inspections of your electrical system. Pull the cover plates on your outlet boxes and switches and inspect the box itself. If it is intact and adequately secured to the wall and ceiling studs they will most likely not have to be replaced. Note that if you plan on adding ceiling fans to rooms you will probably need to either add bracing to that outlet box or replace it with one that is designed to accept a fan.
If your outlets are the old two prong style you will need to replace them with the grounded three prong type. It is a good idea to replace all the outlets and switches in the house. Most municipal codes will require you to use a GFCI (ground fault circuit interrupter) type outlet in the bathroom, kitchen and any other wet areas that are in close proximity to water.
There are a lot of things a homeowner can do to determine just how big a project her or his electrical rework will be. Determining the size of the system you have and the condition of your wiring and other components and developing a plan for any new outlets and circuits you many require will go a long way in planning your budget for a home electrical system update.