Office Building CCTV Systems for Towers of 5–30 Floors

The first thing a cleaning contractor, a night guard or a late-working employee does is turn off the lobby feature lighting. The cameras then have to hold colour in whatever light spills in from the street and the exit signs. That is exactly the condition the 5 MP full colour low-light series is built for: colour images in conditions down to 0.1 Lux without external floodlights and without switching on the camera’s own LEDs.

That matters twice over in an office building. First, evidence: colour is what lets a person be described — jacket, bag, lanyard. Second, discretion: a camera that does not fire a visible LED is far less noticeable in a dim corridor, which is usually what a corporate client wants.

The limit is honest and worth stating in the design: in absolutely no light at all, the built-in fill light is what keeps the image in colour. Where a position is genuinely black — a sealed plant room, an unlit basement corner — say so, and the design will treat it as its own case rather than assume.

Most office towers end up with two recording zones, and the cleanest way to build them is physically: the landlord’s switches and recorder cover the core, the lifts, the car park and the perimeter; a tenant floor runs on its own switch and its own recorder. A single CAT6 uplink between the two cabinets is cheaper than a legal argument about who may delete what.

Where one recorder does serve both, separate the zones by VLAN at the switch and by user permissions at the recorder. The recorders support local user accounts, so the concierge can review the lobby while only the facilities manager can export or erase. Whichever route you take, write the retention period down and hand it over with the system.

• Core and common areas: one recorder, one retention figure, one passphrase holder.
• Tenant floor: separate switch and recorder, or a VLAN plus recorder user accounts.
• Shared evidence: a written export procedure, so a tenant request is a five-minute job rather than an argument.
• Lift cars and lift lobbies are almost always common areas — confirm ownership of the footage before the first incident, not after it.

• Walk the site at night with the lighting set the way it will actually be at 21:00, not at 17:00. Check every ground-floor and entrance camera in colour.
• Confirm each channel is recording at the specified resolution and frame rate, and that the recorder is set to continuous, not motion-only, on entrance and lift channels.
• Play back a real incident window and export one clip end to end, so the client has seen the procedure rather than been told about it.
• Measure the PoE budget with every camera running and the PTZ moving, not on paper.
• Label every channel with floor and position — "Level 6 lift lobby", not "IPC-42" — and save the wall layout before handover.
• Hand over the storage arithmetic so the client can forecast retention as cameras are added: 8–15 GB per channel per day at 5 MP on H.265+.

Two viewers usually need the system: the concierge, who wants the entrance and the lift bank, and the security officer, who wants everything else. A client or a single 4K monitor on the recorder output (HDMI up to 3840 × 2160, layouts of 1/2/4/6/8/9/10/16) covers the first role and most buildings up to 32 channels.

A wall earns its space when the tower wants permanent sight of the gates, the lobby and the car park ramp at the same time. The decoder server handles that: 2 HDMI 2.0 4K@60 Hz outputs per card and up to 36 splits per card, in a 14-slot platform chassis, so a 2×2 wall today can become a 3×3 later without replacing the head-end. Add a network PTZ keyboard (YK-41DP or C300) only where someone genuinely drives a PTZ; otherwise the mouse and the client are enough.