Is knob-and-tube wiring a problem when buying a house in Virginia?

Yes, it is a problem worth taking seriously, but it is a priced problem rather than an automatic reason to walk away. Knob-and-tube wiring is old, it limits insulation, and it can complicate insurance. In Virginia, finding out how much of it is still live, and what replacing it costs, is the buyer's job before settlement.

What knob-and-tube is

Knob-and-tube wiring dates from before 1930, and it can be a fire hazard when in contact with insulation.^[6] You can usually spot it in an unfinished basement or attic: separate single wires held off the framing on white porcelain knobs and passed through porcelain tubes where they cross joists.

What you see in the basement or attic is rarely the whole story. Much of an old house's wiring runs inside finished walls and ceilings, where its condition cannot be judged without an electrician's assessment.

Why it matters when you buy

Insulation. If you plan to add attic or wall insulation, the wiring comes first. ENERGY STAR lists knob-and-tube wiring among the problems you may need a contractor to correct before you seal and insulate an attic.^[6] Budget for the electrical assessment, and any replacement, before the insulation job.

Insurance. The City of Berkeley, California, notes that many insurance providers will not issue or renew homeowner policies for houses with active knob and tube wiring.^[8] Insurers' rules vary, so call yours before you are committed and ask what they need to see.

Modern loads. A modern kitchen, laundry, window air conditioners and a home office may need new circuits even if some old wiring is sound. The electrician's assessment will say how much new capacity the house needs.

Virginia puts the checking on the buyer

Virginia's residential property disclosure law is a buyer-beware law.^[1] The required statement says the seller makes no representations or warranties about the condition of the property, and buyers are advised to do whatever due diligence they think necessary, including a home inspection, before settlement.^[1] Do not expect the seller to raise the wiring.

A home inspection helps, but it has limits. Under Virginia's rules the report is a written evaluation of the readily accessible components of the house, including the electrical system.^[2] Virginia's rules list what the electrical part covers, including the service, the panels, the conductors, overcurrent devices, and the installed fixtures, switches and receptacles.^[2] Unless the home inspection contract limits the inspection, that list also includes the presence of solid conductor aluminum branch circuit wiring.^[2] Read your inspection contract to see what it leaves out.

The catch is the word "accessible." Under the regulation, readily accessible means "available for access without requiring moving or removing of any obstacles."^[3] Wiring inside finished walls and ceilings is usually beyond what an inspector can see. Knob-and-tube spotted in the basement or attic is a sign there may be more you cannot see.

What to do during your inspection period

If the inspector notes knob-and-tube, or you see it yourself, bring in a licensed electrician while you still have time under your contract. Ask them to:

• Tell you which knob-and-tube circuits are still live and which are already disconnected, since some of what you see may be dead.
• Check the panel and service size against what you plan to run.
• Quote the replacement of every live knob-and-tube circuit in writing, with the permit, wall repair and schedule spelled out.

Our guides to what rewiring an old house involves and what it costs to rewire a house in Virginia explain what you are being quoted for. How you use that quote in the purchase is a question for your agent or attorney.

When to call a licensed pro

Assessing and replacing knob-and-tube is electrician's work. Under Virginia law, no individual may work as a tradesman unless licensed,^[4] and under the building code a permit is required before work starts on electric wiring.^[5] A home inspector reports conditions; an electrician is the one to say what is live and what the fix is.

Call an electrician right away, purchase or not, if you find knob-and-tube wiring buried in insulation, since it can be a fire hazard when in contact with insulation,^[6] or if outlets or switches feel unusually warm, which can mean a loose connection that can start a fire.^[7]

You can check an electrician's licence on DPOR's record before you hire.

Find an electrician

Browse Loclis electrical services, look up electricians in Blacksburg, or read more electrical answers, including the signs a house needs rewiring.

Describe the house and the wiring and licensed local electricians quote the assessment and the work.