The short answer
Knob and tube is the original wiring in many Canadian homes built before the mid-twentieth century: single wires run on ceramic knobs and through ceramic tubes, with no ground conductor. Many insurers ask whether any of it is still live, and some will only offer cover once it is replaced or inspected. Prepare an electrician's letter, permit records and photos of the panel, then let a licensed broker find insurers that will consider the home.
- Buyers of a pre-war house whose inspector flagged knob and tube in the attic or basement
- Owners told at renewal that the electrical system needs to be documented
- Anyone partway through a rewire who needs cover while the walls are open
- Landlords of older character homes split into suites
4 licensed brokers in the network handle this. In Alberta, Canada, a request for knob and tube wiring insurance can be offered to up to three of them, chosen because they are licensed for this line and place. They are test brokers while we are in demo.
See the brokers → Outside Alberta, Canada you can prepare and save a request today; sending opens place by place. Brokers answer with their own quotes. Broker.insure does not quote, advise or take commission.
01 / What it covers
The parts worth understanding
Live versus abandoned wiring
Insurers tend to separate wiring that still carries power from wiring left in the walls but disconnected at the panel. Abandoned runs are usually treated very differently, which is why the electrician's wording matters.
Fire and electrical damage
On a policy that accepts the home, a fire that starts in old wiring is normally handled like any other fire claim. The harder question is getting a policy offered in the first place.
Conditions and deadlines
Some insurers offer a policy on the condition that the remaining circuits are replaced within a set period. Read the condition, the deadline and what proof they want when it is done.
The electrical panel
Knob and tube often sits alongside an older fuse panel or a small service. Insurers may ask about the panel size and type as a separate question from the wiring.
Insulation around old wiring
Knob and tube was designed to shed heat into open air. Blown-in insulation packed around it is a concern electricians often note, and an insurer may ask about it.
Renovation in progress
While a rewire is underway, walls are open and contractors are on site. Tell the insurer about the work so the policy reflects a home under renovation.
02 / Get ready
Bring this, and expect these questions
Gather
- A letter from a licensed electrician stating whether any knob and tube remains and whether it is energized
- The electrical permit number and final inspection record for any rewiring, from the municipality or permit authority
- Photos of the electrical panel with the door open, showing breakers or fuses and the main rating
- The home inspection report, with the page that mentions the wiring
- Invoices from any electrical contractor, with dates and the rooms or circuits covered
- The year the house was built and the dates of any major renovations
- A note of which floors or rooms still have original wiring, if any
- Your current policy or any letter from the insurer asking about the wiring
A broker will ask
- Is any knob and tube still connected to power, or has it all been disconnected at the panel?
- Who confirmed that, and do you have it in writing from a licensed electrician?
- Was the rewiring done under a permit, and did it pass final inspection?
- What size is the electrical service, and does the panel use fuses or breakers?
- Is there insulation in the attic or walls where old wiring runs?
- If some wiring remains, when do you plan to replace it?
- Is any part of the home rented to tenants?
Not sure of an answer? Leave it. "Not known yet" is a fine answer, and a broker will help you fill it in.
03 / Build your request
Answer a few questions. Get your own list.
Pick what fits. Your answers shape the list beside them, and they are saved to your request as plain facts a broker can read. "Not sure yet" is always a fine answer.
04 / Three situations
See which one sounds like yours
A buyer of a 1920s house in an inner-city neighbourhood
The home inspector found ceramic knobs on joists in the basement and could not tell whether the circuits were still live. Possession is in four weeks and the lender wants proof of insurance before funding.
First steps. Ask the seller for any electrical permits or invoices, and book a licensed electrician to trace the circuits before conditions come off if timing allows. Give the broker the inspection page and the electrician's findings, and ask which insurers will consider the home and on what conditions.
A long-time owner with a partial rewire
An owner rewired the main floor ten years ago but the second floor bedrooms still run on original circuits. A new renewal questionnaire asks directly about knob and tube, and the honest answer is yes.
First steps. Get an electrician to document exactly which circuits remain and quote the work to replace them. Bring the earlier permit and the quote to the broker, and ask whether insurers would offer cover with a replacement deadline or need the work finished first.
A landlord with a converted triplex
A character house was split into three suites decades ago. The landlord believes the wiring was updated, but an electrician opening a wall for a repair found old knob and tube still feeding one suite.
First steps. Ask the electrician for a written report of what was found and what remains active. Tell the broker the home is rented, how many units there are and the plan for the remaining wiring, since rental use and old wiring are both weighed.
05 / Words you will hear
The jargon, in plain words
- Knob and tube
- Early electrical wiring where single conductors run on porcelain knobs and pass through porcelain tubes in framing. It has no ground wire and predates sheathed cable.
- Energized
- Connected to the panel and able to carry power. Insurers care far more about energized knob and tube than wiring that has been cut off.
- Electrical permit
- Permission from the local permit authority to do electrical work, followed by an inspection. The permit record is independent proof the work was done and checked.
- Ampacity
- How much current a service or circuit is rated to carry, shown in amps on the main breaker or fuse. Older homes often have a smaller service.
- Condition of cover
- A requirement written into a policy, such as replacing remaining wiring by a certain date. Missing it can affect the policy or a claim.
06 / Common mistakes
What trips people up
- Answering no on an application because you assume the previous owner removed everything, without anything in writing.
- Relying on a home inspector's visual note when the insurer wants an electrician's confirmation.
- Rewiring without a permit, which leaves no official record that the work was done properly.
- Forgetting abandoned wiring is still worth documenting, so the insurer can see it is disconnected.
- Missing a replacement deadline that was written into the policy as a condition.
Ready when you are
Turn this into one clear request.
Save it, add what you know, and choose when to send it. A licensed broker who handles knob and tube wiring insurance takes it from there.
07 / Questions people ask
Straight answers
Can you insure a house with knob and tube wiring?
Sometimes, but options are narrower. Some insurers decline homes with any live knob and tube, some accept it with an electrician's inspection, and some offer cover on the condition that it is replaced within a set time. A broker can approach several insurers with the same documents, which is easier than applying to each one yourself.
What should an electrician's letter say for insurance?
It should be on the contractor's letterhead with their licence or registration details, the property address and the date. It should say whether any knob and tube remains, whether it is energized, the size and type of the panel, and what work was done or is recommended. Vague wording such as looks fine tends to prompt more questions.
Does disconnected knob and tube still matter?
It usually matters much less than live wiring, but insurers may still ask. Old wire left in the walls and disconnected at the panel carries no current. A written statement from an electrician that it is abandoned and isolated is the document that lets an insurer treat it that way rather than guessing.
Why do insurers worry about knob and tube?
The wiring is often close to a century old, has no ground, and its insulation can become brittle. Later owners sometimes spliced new circuits into it or buried it in insulation it was never designed for. Each insurer weighs these concerns differently, so the questions and conditions you meet can vary from one to the next.
How do I find out if my house has knob and tube?
Look for porcelain knobs or tubes on joists in an unfinished basement or attic, and two separate wires rather than one sheathed cable. A two-prong outlet is a hint but not proof. The reliable answer comes from a licensed electrician tracing circuits from the panel, which is also the record an insurer can use.
Will replacing knob and tube change my insurance?
Documented replacement often widens the choice of insurers and can remove conditions on the policy. Keep the permit, the final inspection record and the contractor's invoice together, and send them to your broker when the work is done. Ask the broker to confirm the insurer has updated its record so the question does not return at renewal.
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General information, not insurance advice. Broker.insure is a directory and request service: it is not an insurer and does not quote, bind or advise. Policy terms, availability and what is required where you live depend on your situation and on licensed professionals. Updated 2026-10-31.