A full home electrical rewire is sometimes the safest and most cost-effective solution for Ontario homes with outdated wiring. This guide covers the key triggers, process, and 2026 GTA cost ranges.
When a Full Rewire is Required
Knob-and-tube wiring (K&T): Pre-1950 ungrounded system. Most Ontario insurers will not cover homes with active K&T at standard rates. Cannot be buried under insulation per Ontario Fire Code. Rewire required for insurance, renovation, or sale.
Aluminum wiring (1960s-1970s): Aluminum oxide forms at connections creating fire hazard. Options: full rewire (best), or pigtailing with CO/ALR devices at every connection. Most buyers demand full rewire before purchase.
Federal Pacific Stab-Lok panels: Breakers fail to trip — documented fire hazard. Replace immediately regardless of wiring type.
60-amp service: Insufficient for any modern Ontario home. Upgrade to 200A before major renovation.
Rewire Process
Remove all existing wiring. Install new 200A service. Run new NMD-90 Romex throughout. Install ESA-compliant outlets, switches and fixtures. ESA permit and final inspection.
Minimally invasive (fishing through walls): more expensive — walls remain intact but labour is higher. Full rewire with walls open: done during gut renovation for best access and cost efficiency.
Costs (GTA 2026)
- Full rewire, 1,500 sq ft, walls open: $15,000-$30,000
- Full rewire, minimally invasive: $25,000-$50,000
- Panel upgrade only (100A to 200A): $2,500-$5,000
- ESA permit and inspection: $300-$600
Full guide: https://telegra.ph/Ontario-Whole-Home-Rewire-Guide-2026---When-to-Rewire-Costs-and-ESA-Requirements-04-26