What removing knob and tube actually involves
Knob & Tube Kingston connects homeowners with licensed ECRA/ESA electricians who remove knob-and-tube wiring the way insurers require it to be done: under an ESA permit, fully documented, and finished with a Certificate of Inspection. If you're picturing a demolition site (plaster torn open in every room, the family in a hotel for a month), that is not how a modern rewire works in a Kingston century home.
Knob and tube was standard from roughly the 1880s to the 1940s: two separate strands of copper strung through ceramic knobs and tubes, insulated with rubberized cloth that has been drying and cracking for close to a century. It has no ground wire (no safe escape path for electricity when something fails), was never rated for modern loads, and becomes genuinely unsafe when it's buried under blown-in attic insulation. The fix isn't a repair. The fix is replacement, circuit by circuit, until nothing old is left live.
How the crew gets new cable through finished walls
The core technique is fishing: the electrician runs new grounded NMD90 cable (the standard modern house wiring, one sheathed cable with a built-in ground wire) through the existing wall and ceiling cavities, working from the basement below and the attic above. Access comes from small, strategic openings (behind outlet boxes, at ceiling fixtures, inside closets) that are patched at the end of the job. In most homes, what's visible afterward is a handful of neat drywall patches ready for paint, not open framing.
As each new circuit goes live, the old knob-and-tube run is disconnected and, wherever it's accessible, physically removed. The dead wiring left inside sealed cavities is abandoned in place. That's standard practice, and the ESA inspector expects it. What matters is that nothing old carries current anymore.
Partial vs full rewire
Very few Kingston century homes are 100% knob and tube in 2026. Most have been renovated in stages (a rewired kitchen from the 90s, new basement circuits from a 2010 finishing job), with the original wiring surviving in the upstairs bedrooms and the ceiling lighting. That's why the first step is always a trace: the electrician identifies exactly which circuits are still live knob and tube.
- Partial replacement: only the remaining live knob-and-tube circuits are rewired. Typical range $3,000–$6,000. Often all your insurer actually requires
- Full bungalow rewire: every circuit replaced, typically $5,000–$8,000
- Full two-storey rewire: $8,000–$15,000 depending on finishes and access
- Large century home + 200 A panel upgrade: $14,000–$25,000, wiring, panel and service all handled in one project
What moves your price up or down (storeys, finished ceilings, panel age, attic and basement access) is broken down in detail on our 2026 cost page.
How long it takes, and living through it
Most removals run 2 to 5 working days. A partial replacement can be done in two; a full two-storey rewire takes closer to five; a large home with a panel upgrade can take more than a week. Crews work room by room and keep essential circuits (fridge, heat, some lights) powered overnight, so you can almost always stay in the house. Expect dust sheets, furniture moved away from the walls, and short planned outages during changeovers.
What's included when it's done right
In Ontario, this work must be performed by a Licensed Electrical Contractor (ECRA/ESA) under an ESA permit. That is the law, and it is also the only way to get the document that actually solves your problem. A proper quote includes:
- The trace and written scope: full or partial, no guesswork
- New NMD90 grounded cable, boxes, outlets and switches
- The ESA permit and inspection fees, filed and booked by the contractor
- Patching of the access openings
- The ESA Certificate of Inspection at the end
That certificate is the entire point. It is the document that makes your insurer remove its conditions and restore standard rates, typically saving Kingston homeowners $500–$1,500 per year versus surcharged high-risk coverage. The full mechanics of refusals, conditional letters and deadlines are on our insurance page, and what the ESA inspection itself involves is covered on the ESA inspection page.
Holding an insurance letter with a 30–90 day deadline? A removal can be completed inside that window: quote first, permit filed, crew booked, ESA inspection on the final day. Write your deadline in the free quote form. Rewires with an insurer's deadline are given priority on the schedule.