The Real Estate agent is asking me to provide a "certificate of smoke alarm compliance" to complete Form 24 (when selling a property).
I argue no such thing exists, and that anyone can go buy interconnected smoke alarms which are AS 3786:2014 compliant. (Eg from Bunnings). Install following the guidelines, test interconnectivity, then state the property is compliant.
If they are mains powered, then while you can buy them, you can't legally install them.
If they are battery powered only, then yes you can install them yourself.