Start with every bedroom

Count one smoke alarm inside each bedroom. A four-bedroom home begins with four bedroom alarms before hallways or levels are considered.

Add every separate sleeping area

Add an alarm outside each distinct sleeping area. Bedrooms grouped along one hallway may share an outside sleeping-area alarm; separated bedroom wings may require more.

Cover every level

Every level needs coverage, including the basement. If the bedroom and hallway count does not place an alarm on a given level, add one there. Large or unusual spaces may require additional units.

Then evaluate CO alarms

CO alarm placement is related but separate. CPSC recommends CO alarms on each level and outside sleeping areas, while Colorado law establishes requirements for covered homes.

Safety references

Primary sources used for this page:

Manufacturer instructions and current local requirements control. For an emergency, call 911.