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Smoke and carbon monoxide alarm planning checklist

Plan smoke alarms on every level and in sleeping rooms, and CO alarms on every level and outside sleeping areas; check each model’s replacement age.

Plan smoke and carbon monoxide alarms as a shopping and replacement list: listed smoke alarms on every level, inside sleeping rooms, and in the hall outside those rooms; listed CO alarms on every level and outside sleeping areas, especially where fuel burns or a garage is attached. The exact spots are in the instructions in the box and in your local code. This page will not give inch measurements to install against.

Interconnected hardwired work belongs to an electrician or an alarm company. Households can plan, test with the button, and replace units according to their model instructions and replacement age.

Step 1: Count levels and sleeping rooms

1. Walk each floor, including a basement people use.
2. Count rooms where someone sleeps, including a guest room that is used.
3. U.S. Fire Administration guidance calls for smoke alarms on every level, inside each sleeping room, and outside sleeping areas. Confirm that pattern on its current smoke-alarm page and with your fire authority before you treat it as your city’s rule. Local amendments differ.
4. Do not place an alarm where the manufacturer says not to: next to a shower, a stove, or a supply vent that will cause nuisance alarms and then get disconnected. The box instructions win over a convenient nail.

Step 2: Add CO alarms for fuel and the garage

CPSC recommends listed carbon monoxide alarms on every level and outside sleeping areas. This is especially important when the home has fuel-burning appliances, a fireplace, or an attached garage. Confirm locations in the CO alarm’s instructions and local rules. A smoke alarm does not detect CO unless the unit is listed for both and labeled that way. Read the front of the package. CPSC’s carbon monoxide guidance gives the general placement pattern; the model instructions and local authority decide exact locations.

Step 3: Read the date on the back

Read whether the date on the unit is a manufacture date or an explicit replace-by date. U.S. Fire Administration guidance calls for replacing smoke alarms 10 years after manufacture; do not add 10 years to a replace-by date. CO alarm lifetimes vary by model, so use its instructions or end-of-life signal. Replace an expired unit even if its button still sounds.

Step 4: Test with the button, on a schedule you will keep

Press the test button monthly. Use a monthly reminder; the seasonal walk is an extra chance to check dates, not a substitute for monthly testing. A button test checks the alarm circuitry; it does not prove the sensor is accurate or that every corner is covered. Follow the manual if you use a listed test method beyond the button. Do not hold a flame to an alarm.

If you are also adding smart-home gear, do not cover, paint, or unplug an alarm to make a camera or a sensor fit. See the setup plan and keep alarms outside that project.

Step 5: Know the stop rules

• A chirp can mean a low battery or an expired unit. Read the manual for that chirp pattern. Replace the battery or the unit as it says. Do not remove the alarm and leave the hallway bare.
• If you smell gas, follow the gas utility’s emergency instructions and leave if they tell you to. This site cannot dispatch help.
• If an alarm sounds and you do not know why, get people out and call the fire department from outside. Do not spend the next minutes searching for a blog.
• Hardwired or interconnected systems that need new cable are not a DIY add-on from this checklist.

Example: a two-level house with a gas furnace and an attached garage

The list is: a smoke alarm inside each of three bedrooms, one in the upstairs hall, one on the main level, and one in the basement that people use. A CO alarm goes on each level used for living, because of the furnace and the attached garage, in spots the CO unit’s manual allows. Existing smoke alarms show a manufacture date eleven years ago, so they are on the replace list even though the button still sounds. No one measures inches from a bedroom door for this guide. They take the count to the store and then follow the new boxes. This is a shopping sketch. The fire authority and the manuals decide the final spots.

Related guides

• Seasonal home maintenance checklists
• How to plan a smart-home setup
• How to plan garage and workshop storage
• Workshop electrical safety planning checklist
• Privacy settings for speakers and cameras

Last updated: October 21, 2026

Last reviewed October 22, 2026. Suggest a correction

Information on this site is for general educational purposes and is not professional advice.

Parent topic: Home & Garden