Hardwired and interconnected per code, battery backup included—calculate the complete installed cost for residential smoke and carbon monoxide detectors so your quote covers every device, home-run wire, and code requirement before the AHJ inspection.
The 2021 IRC (R314) requires smoke alarms in each sleeping room, outside each sleeping area, and on each story of the dwelling including the basement. Carbon monoxide alarms (R315) are required outside each sleeping area and on each level where fuel-burning appliances are present. These are minimums. NFPA 72 also requires interconnection — when one activates, all must sound. In retrofit installations with hardwired detectors, the 3-wire interconnect (hot, neutral, interconnect) is what makes this work. Installers who put in battery-only units and call it done may satisfy the letter of the code for some jurisdictions, but fail the intent of interconnection. When quoting hardwired jobs, quote interconnected systems — and document that interconnect was verified by test before you leave.
Smoke detectors have a manufacturer-recommended service life of 10 years. CO detectors: 5–7 years. Most homeowners don't know this and replace units only when they start chirping. A chirping detector in a bedroom at 3 AM is an emergency call, not a scheduled job. Build a detector replacement program into your service agreement: "We note the manufacture date on all life-safety devices during every visit. Detectors approaching end-of-service-life are flagged for proactive replacement." A 2,000 sq ft home with 7 detectors due for replacement is a $600–$900 job. The homeowner who knows they're getting 10-year protection is different from the homeowner who just wants the chirping to stop.
Smart interconnected detectors (Nest Protect, First Alert OneLink) add $50–$80/unit over standard hardwired models. The pitch: "If this detector goes off while you're on vacation, you get a push notification telling you which room triggered it — you can call the fire department with that information instead of just 'something is wrong at my house.'" For homes with frequent travelers, second-home owners, or vacation properties, this is a no-brainer upsell. Smart units also self-test monthly and notify the homeowner when a unit is degraded or needs replacement — eliminating the 3 AM chirp service call. Present it on every quote. The additional cost is one restaurant dinner. The benefit is knowing your house isn't on fire while you're in another state.
The Electrician's Business Starter Kit includes a flat-rate price book for 30 common residential and commercial electrical jobs, inspection checklist, and service agreement template. Guide from $19 — Complete Kit with all 19 templates, $49.
Get the Electrician's Kit →Smoke and CO detector installation pricing varies based on detector type (battery, hardwired, hardwired with battery backup), whether interconnection is required, and how many units are needed by code. This calculator builds your quote from unit count, wiring type, and labor time so you can price residential detector jobs consistently and profitably.