Multi-tenant buildings like hotels or apartment complexes benefit from intercom systems by allowing invited guests onto the property without a dedicated person screening each guest.
In a hotel setting many of the exterior doors remain locked and only accessible by card key issued by the front desk. In the afterhours sometimes the main entry is also locked and each guest must be manually let in. However, if an intercom system was deployed and connected to the doors, the front desk can allow entry with a push of a button without leaving their desk.
This is extremely beneficial to guests who may have left their keys in their room before leaving, or who may need access to amenities such as a gym, laundry room, pool, or other areas that are otherwise off limits.
Apartments are another common multi-tenant building that can benefit from an intercom system. Commonly, gated apartment complexes use intercoms to allow the homeowner screen the guest prior to entry. These intercoms are connected to an electronically controlled gate to eliminate the need for a staffed guard to open the gate. Not only does this help maintain a high reputation of the complex but prevents unwanted solicitors.