How much does smoke alarm installation cost?
Installing a smoke alarm typically costs $70–$150 per unit including the detector and labor. Battery units at existing spots are cheapest; hardwired, interconnected alarms needing new wiring run $150–$250 each, with per-unit cost dropping on whole-house jobs.
Ranges are typical planning guides — actual price varies by region, access, materials and your local pro. Always get a written quote.
| Scenario | Typical cost | Notes |
|---|---|---|
| Battery unit, simple mount | $40–$90 | No wiring needed |
| Hardwired replacement | $70–$150 | Wiring already in place |
| Hardwired, new wiring run | $150–$250 | Cable + interconnect |
| Whole house (5–8 alarms) | $400–$900 | Cheaper per unit |
What affects the price
Battery vs hardwired
Battery alarms just screw to the ceiling. Hardwired alarms tie into a circuit and interconnect so all alarms sound together — required by code in many areas, and more labor to fit where no wiring exists.
How many at once
The call-out fee is fixed, so doing every bedroom, hallway and level in one visit brings per-unit cost down sharply compared with one-off installs.
Detector type
Combination smoke/CO units, 10-year sealed-battery models and smart alarms cost $30–$100 more per unit than a basic ionization detector.
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How much does smoke alarm installation cost?
Typically $70–$150 per unit installed, including the detector. New hardwired runs cost $150–$250 each, and whole-house jobs of 5–8 alarms run $400–$900.
Do smoke alarms need to be hardwired?
In most US jurisdictions, new construction and major remodels require hardwired, interconnected alarms with battery backup. Existing homes can often keep battery units — check local code.
How many smoke alarms does a house need?
Code generally requires one in each bedroom, one outside each sleeping area, and at least one per level including the basement — typically 5–8 for an average home.