Selling a House With Knob-and-Tube Wiring
2 min read · Last updated 2026-08-05 · Reviewed by Camilo Palacio, Licensed Florida Real Estate Professional (License #3280644, REALTOR®)
Knob-and-tube wiring, installed in most U.S. homes roughly from the 1880s through the 1940s, has no ground wire and worries insurers enough that many carriers won't write a new policy on a home with active knob-and-tube still in place. Without an insurance binder, a financed buyer's lender usually can't close. Selling directly to a buyer who purchases as-is removes that requirement.
| Factor | Traditional Route | Cash Flow Deals |
|---|---|---|
| Insurance binder | Many carriers won't issue a policy until the wiring is replaced or certified safe | No new insurance policy required to close |
| Lender or appraisal review | Appraiser flags active knob-and-tube as a safety hazard needing repair | No repair required before closing |
| Rewire cost | Seller often faces a full electrical rewire before a buyer's lender will fund | Seller pays nothing toward rewiring |
Why knob-and-tube wiring worries insurers
Knob-and-tube wiring was standard through roughly the 1940s, uses no ground wire, and wasn't designed for the electrical load a modern home actually draws. Insurance carriers have gotten far more specific about wiring type in underwriting, and active knob-and-tube is one of the most common reasons a company declines a new policy outright or tells a homeowner to have it inspected and certified before they'll bind coverage.
How it shows up on an appraisal or inspection
A home inspector will typically identify knob-and-tube by its distinctive ceramic knobs and tubes running through framing, and will note whether it's still active or has been abandoned in favor of newer wiring. If it's active, an appraiser reviewing the file for a financed sale is likely to flag it as a safety item that needs correcting, since guidance under standard loan property requirements treats unsafe electrical systems as a condition to be resolved before funding.
What a full rewire costs
Replacing knob-and-tube throughout a house means opening walls in most cases, not just swapping a panel, so the cost runs from a few thousand dollars in a small home to well into five figures in a larger one, depending on square footage and how accessible the wiring is. It's rarely a job that can be scheduled and finished inside a normal closing timeline.
Disclosure duties on old or unknown wiring
If you know your home has knob-and-tube wiring, most states expect you to disclose that as a known condition, whether or not it's currently active. Exact disclosure rules vary by state, so check your state's specific requirement, but wiring type is a common item on standard seller disclosure forms nationwide, so it's rarely something you can leave blank.
Selling as-is instead of rewiring first
Cash Flow Deals buys homes directly, arranged through a licensed local broker partner, for one flat fee agreed on before closing. There's no insurance binder to chase and no rewire required to get to the closing table. You disclose what's there, and the price holds.
Common questions
What is knob-and-tube wiring and how old is it?
It's an early electrical wiring method using ceramic knobs and tubes to run wires through framing, with no ground wire. It was common in U.S. homes roughly from the 1880s through the 1940s.
Why won't insurance companies cover homes with knob-and-tube?
It lacks grounding and wasn't built for modern electrical loads, which insurers treat as a higher fire risk, so many carriers decline new policies or require replacement first.
Do I have to rewire before I can sell?
Not to sell outright, but a financed buyer's insurer or lender will likely require it before closing. Selling directly to a buyer who purchases as-is removes that requirement.
How much does it cost to replace knob-and-tube wiring?
A full rewire typically runs from a few thousand dollars in a smaller home to well into five figures in a larger one, since it usually means opening walls to access the old wiring.
Can I sell a house with active knob-and-tube wiring?
Yes, to a direct buyer purchasing as-is. A financed buyer will likely run into their lender or insurer requiring it be addressed first.