What does a hardwired smoke and CO upgrade cost in Toronto?

Upgrading to hardwired smoke and CO detectors in Toronto typically runs $800–$2,500+ depending on the number of units, your home's wiring, and whether you're adding interconnected alarms throughout the house.

Hardwired detectors are permanently connected to your home's electrical system with a battery backup, and in interconnected systems, when one alarm triggers, they all sound simultaneously. This is the gold standard for home safety and is required under the Ontario Building Code for new construction and major renovations. Most Toronto homeowners upgrade during a renovation or after a home inspection flags aging battery-only units.

What drives the cost is primarily the number of detectors and the complexity of running new wiring. A typical Toronto semi-detached or detached home needs one smoke detector per floor, one outside each sleeping area, and CO detectors on every level with a fuel-burning appliance or attached garage. That often means 6–10 units in a standard two-storey home. If your home already has wiring roughed in from a previous hardwired system, costs drop significantly. Older homes in neighbourhoods like The Annex, Leslieville, or Scarborough post-war bungalows often require new wire runs, which adds labour time.

Typical Toronto Cost Ranges

• Basic upgrade (3–4 detectors, existing wiring): $800–$1,200
• Mid-range (6–8 detectors, some new wire runs): $1,200–$1,800
• Full home with new wiring, smart detectors (Nest, Kidde): $1,800–$2,500+

Unit costs for quality combination smoke/CO detectors (Kidde, First Alert, Nest Protect) range from $50–$150 each. Labour is the bigger variable — expect $75–$120/hour for a licensed electrician in the GTA.

This is not a DIY project in Ontario. Any hardwired electrical work requires a licensed electrician and an ESA (Electrical Safety Authority) permit. Unpermitted electrical work can void your home insurance and create serious liability issues if there's ever a fire. The ESA permit for a detector upgrade is relatively inexpensive (typically $100–$200) and includes an inspection that gives you documented proof the work was done correctly — worth every penny for a safety system.

Ontario Fire Code requirements are worth knowing: smoke alarms are mandatory on every storey and outside all sleeping areas. CO alarms are required on every storey that has a fuel-burning appliance, fireplace, or attached garage. If your home doesn't meet this standard, you're technically in violation and it affects your insurance coverage.

Your next step is to get 2–3 quotes from ESA-licensed electricians who can assess your existing wiring and give you an accurate scope. Browse licensed electrical contractors in the Toronto Construction Network directory to find verified professionals in your area. When calling, ask specifically whether they'll pull the ESA permit — any reputable electrician will say yes without hesitation.