Home electrical systems cause around 32,000 house fires every year, making it the third leading cause of residential fires in the U.S., according to the National Fire Protection Association (NFPA).  While not the leading cause of fire loss, electrical accidents are the most expensive, resulting in almost $1.3 billion in annual damage from 2015 to 2019, according to the NFPA.
While homeowners insurance will cover damage to electrical wiring or the damage it causes after a power surge, the type and condition of your home’s electrical work can have an impact on your rates. Some insurance companies may also deny coverage to homes with aluminum or knob-and-tube electrical wiring — two types of wiring that are considered out of date and hazardous.
If you’re buying an older home with knob-and-tube or aluminum wiring, consider asking the seller to have the wiring replaced. Not only is nonmetallic wiring a safer option, but it could also land you significantly cheaper home insurance rates.
Can you get homeowners insurance with aluminum wiring?
It depends. If it's installed safely, there are some insurance companies that will insure your aluminum wired home. But most standard insurance companies refuse to insure homes with aluminum wiring, and there's precedent for this.
Aluminum wiring, the preferred option for homes built in the 1960s and 70s, is outdated and no longer up to building code in many areas. When installed correctly and kept in good condition, it can be a safe form of electricity, but some insurance companies may charge significantly higher rates or deny coverage to homes wired this way.
Compared to safer electrical wiring options like nonmetallic or copper, insurance companies consider aluminum wiring a fire hazard. A 2011 report by the U.S. Consumer Product Safety Commission found that homes with aluminum wiring were 55 times more likely to have one or more wire connections at outlets reach “fire hazard conditions” than homes wired with copper. 
Aluminum is less durable than copper, giving it far shorter life span. Furthermore, aluminum heats up at a greater rate than copper, and improper connecting or splicing to copper can cause oxidation. Aluminum oxide produces excessive heat, and this often leads to fires.
Is a house with aluminum wiring insurable?
If your home's electrical is made up of aluminum wiring, you should be able to find a company to insure it. However, you'll likely be charged far higher rates than a home with modern electrical wiring.
Can you get homeowners insurance with knob-and-tube wiring?
Knob-and-tube, also known as K&T wiring, was a popular method of electrical wiring before the 1950s and is considered an out-of-date form of electricity. This wiring is housed in porcelain insulating tubes, whereas modern copper wiring typically runs through PVC pipe or plastic tubes.
Like aluminum wiring, K&T is brittle and prone to cracking and deterioration, leading some companies to charge higher rates or deny coverage to homes wired this way.
How to insure homes with old electrical wiring
If you’re insuring an older home with aluminum or K&T wiring, your insurance company will likely perform an interior inspection shortly after your policy becomes active. Like any systems in your home, if your wiring has any visible signs of wear and tear that could prove hazardous to your home, your insurance company may require you to make repairs or upgrades, or risk being dropped from your policy.
If you can’t afford electrical upgrades to your property and need insurance right away to fulfill mortgage requirements, consider getting coverage through an excess or surplus lines insurer.
Surplus carriers specialize in insuring risks (such as homes with bad roofs or obsolete electrical wiring) that are denied coverage by most standard insurance companies. While surplus lines coverage is a fine last-resort option, it’s typically expensive and lacks the coverage quality of standard homeowners insurance.
Learn more >> What is surplus lines insurance & when do I need it?
How much does it cost to replace aluminum wiring?
Replacing a home's electrical wiring costs around $1,406 on average, with most wiring and rewiring projects costing anywhere from $555 to $2,286, according to Home Advisor.