When are smoke alarms not required in residential construction according to the IRC?

Smoke alarms are specifically required by the International Residential Code (IRC) to be installed in various situations involving residential construction, primarily to ensure the safety of occupants by providing early warning in case of fire. However, there are certain circumstances under which smoke alarms are not required.

When adding an outdoor deck, the construction does not involve alterations to any living space that would increase the risk of fire hazards or significantly change the configuration of the residence itself. Outdoor decks do not typically require the installation of smoke alarms since they are not part of the indoor living areas where smoke alarms are mandatorily installed according to the IRC. The focus of smoke alarm requirements is primarily on enclosed spaces where inhabitants reside.

In contrast, situations such as installing a new HVAC system, converting a garage (which may involve changing the nature of occupancy), or adding a new roof could potentially affect other safety systems or environments where smoke alarms are typically necessary, since they may involve indoor space modifications or changes in structural occupancy. Hence, those updates would necessitate compliance with smoke alarm requirements as per the IRC.