The requirements of residential sprinkler systems are similar across the three installation standards, with a few variations to provide cost-saving options for homeowners. Where additional protections are necessary or desired, it is up to the engineer to specify.

After more than 20 years of work in the Legionella field, leading outbreak investigations and resolutions as well as performing building audits, I’ve found the two single most critical variables for controlling Legionella risk are temperature and water age (time-to-tap).