All states have laws (statutes) that require landlords to install and maintain smoke detectors in leased residential premises (apartments, homes).

Some states such as Iowa, Maine, Massachusetts, Ohio, and Vermont require photoelectric or ionization sensors—at least in new construction. And Oregon requires smoke detectors with a HUSH mechanism that allows the alarm to be silenced or temporarily desensitized for 7 minutes while a known condition such as cooking is causing the alarm to activate.

Most states also require landlords to install and maintain carbon monoxide detectors in leased residential premises. Smoke and carbon monoxide detectors are widely available in the same device.

In Washington State, landlords are required by law to install and maintain smoke detectors in all leased residential premises, including apartments and homes. This requirement is mandated by the Washington State Building Code and the Residential Landlord-Tenant Act (RCW 59.18.060). The law stipulates that smoke detectors must be installed in accordance with the manufacturer's instructions and in specific locations within the dwelling, such as outside of sleeping areas and on each floor of the residence. Additionally, Washington State law (RCW 59.18.255) requires landlords to install carbon monoxide alarms in existing residential dwelling units and in new construction, with specific placement requirements as well. Landlords are responsible for ensuring that these devices are in working order at the beginning of a tenancy, while tenants are responsible for maintaining the devices, including battery replacement, during their occupancy unless the lease specifies otherwise.