@Ashlee117
If the back yard is one of your Guests fire escapes from your rental you should make it available. My garage is a route out of my property but not a shared area, what we did is use an electric keylock that is set to autolock after 3 minutes. The Guests pin for their area also works on the garage lock. My locks are tied to an Alarm app on my phone. It sends me a notification what lock is being open and records the pin used, I haven't had a need but if I did wake up and suspected unnecessary access to my garage, the system has a report with who and when every day.