Aluminum Wiring in Older Homes: Risks and Solutions

Between roughly 1965 and 1973, aluminum wire was widely used in residential branch circuit wiring as a cheaper alternative to copper. That era’s aluminum wiring is now considered a fire hazard. If you own or are buying a home built during this period, understanding the issue—and your options—is important.

Why Aluminum Wiring Is a Problem

Aluminum expands and contracts more than copper when it heats and cools with electrical use. Over time, this movement causes connections at outlets, switches, and fixtures to loosen. Loose connections create resistance, which generates heat, which can cause arcing or fire.

Additional issues with aluminum wiring:

• Oxidation. Aluminum oxidizes quickly when exposed to air. Aluminum oxide is a poor conductor, further increasing resistance at connection points.
• Creep. Aluminum “creeps” under pressure over time, meaning it slowly deforms at screw terminals, loosening the connection.
• Incompatible devices. Many standard outlets and switches are rated for copper only (marked “CU” or “AL” for aluminum-rated). Using CU-only devices with aluminum wire creates a fire hazard at the terminal.

The U.S. Consumer Product Safety Commission (CPSC) found that homes with aluminum wiring are 55 times more likely to have wire connections reach “fire hazard condition” compared to homes with copper wiring.

How to Identify Aluminum Wiring

Check the wire sheathing. In your electrical panel or in visible wiring runs (basement, attic, crawl space), look at the outer jacket. Aluminum wiring is typically labeled “AL” or “ALUMINUM” printed on the jacket.

Look at the color. Where wire insulation is stripped at connections, aluminum wire is silver-colored. Copper wire is orange-brown.

Check your home’s build date. If your home was built between 1965 and 1973, assume aluminum wiring is possible and have a licensed electrician inspect it before drawing conclusions.

Note: Aluminum wiring is still used today for service entrance cables (the large wires coming from the utility to your panel) and for large-gauge feeder circuits. The concern is specifically with the smaller branch circuit wiring (15A and 20A circuits to outlets, switches, and fixtures) that was common in this era.

What to Do About Aluminum Wiring

There are three accepted approaches, in order of preference:

Option 1: Full Rewiring (Best)

Replace all aluminum branch circuit wiring with copper. This is the most thorough solution and eliminates the hazard permanently. It is also the most expensive—typically $8,000–$25,000 for a whole-house rewire depending on home size and local labor rates.

Full rewiring is the right call if:

• You’re doing a major renovation that opens walls anyway
• You’re planning to sell and want to disclose no aluminum wiring issues
• You have the budget and want a permanent solution

Option 2: Pigtailing with CO/ALR Devices (Practical for Most)

At every outlet, switch, and fixture connection, an electrician splices a short length of copper wire (“pigtail”) to the existing aluminum wire using a COPALUM connector (the CPSC-approved method) or an AlumiConn connector (also accepted). The devices are then connected to copper wire.

COPALUM connectors require a special crimping tool and must be installed by a trained electrician. AlumiConn connectors are twist-on lugs that more electricians can install.

Simultaneously, replace all outlets and switches with CO/ALR-rated devices (also marked “CU/AL”). These devices are designed for aluminum connections and don’t have the same creep/oxidation problems.

Pigtailing a whole house typically costs $1,500–$5,000 depending on the number of connections and local rates.

Option 3: CO/ALR Device Replacement Only (Minimum)

Replace every outlet and switch with CO/ALR-rated devices. This does not fix the connection at the device terminal (aluminum to aluminum is still a concern), but it reduces risk compared to CU-only devices. This is considered a partial mitigation, not a full fix.

This is the lowest-cost option but also the least thorough. The CPSC considers pigtailing the preferred approach.

What About Homeowner’s Insurance?

Many insurance companies will ask about aluminum wiring on your application. Some will:

• Charge a higher premium for homes with aluminum wiring
• Require an electrical inspection before issuing a policy
• Decline coverage until the issue is remediated

If you’re buying a home with aluminum wiring, verify with your insurance carrier before closing.

Costs Summary

Solution	Typical Cost
Electrical inspection	$200–$500
Full rewire (whole house)	$8,000–$25,000
Pigtailing (whole house)	$1,500–$5,000
CO/ALR device replacement only	$500–$2,000

FAQ

Is it safe to live in a house with aluminum wiring?

Yes, with appropriate mitigation. Millions of homes have aluminum wiring and are safe because the connections have been properly addressed. The risk comes from unmaintained or improperly connected aluminum wiring. Have a licensed electrician inspect your home, fix any problem connections, and replace non-CO/ALR devices.

Can I buy a house with aluminum wiring?

Yes, but factor remediation cost into your offer. Get an electrical inspection before closing. The cost of proper pigtailing or rewiring is not enormous, but it’s real. Also confirm your homeowner’s insurance will cover the property.

How do I find an electrician who works with aluminum wiring?

Ask specifically about aluminum wiring experience and whether they use COPALUM or AlumiConn connectors. Not all electricians are trained on COPALUM crimping. An electrician who just says “I’ll replace the outlets” without mentioning pigtailing may not fully understand the issue.

Does aluminum wiring have to be disclosed when selling?

Disclosure requirements vary by state, but in most states, known material defects—including known electrical hazards—must be disclosed. Aluminum wiring is widely considered a material defect. Consult a real estate attorney in your state.

My home was built in 1972 but I see copper wire at the outlets. Is it safe?

It may already have been pigtailed—a previous owner may have had remediation done. Ask to see documentation or have an electrician trace the wiring back to confirm whether the branch circuits are aluminum or copper, and whether any pigtailing was done correctly.