The building has a fully-monitored alarm system for each unit. So when you leave the building, you can be confident that your offices are alarmed, without having to rely on anyone else. When the last business leaves the building on an evening, the alarm is set for the common areas.
Plus a multi-point IP CCTV system monitoring the exterior, and all access through the reception. All other doors are secured and alarmed and used for egress in the case of a fire only.