The question arrives in that form surprisingly often. A building has twenty-three floors, so somebody assumes twenty-three cameras, maybe forty-six if they are being thorough.
The real answer is not distributed that way at all. On the tower this article draws on, roughly a third of the cameras sat in the first two levels, and most floors above the fourth got exactly one.
That distribution is not a compromise. It is the design.
What the schedule actually looked like
Recorded at a site meeting, floor by floor:
| Location | Cameras |
|---|---|
| Ground floor | 8 |
| Parking lift lobby | 3 |
| Fourth-floor ramps | 1 |
| Fourth to thirteenth floors | 1 per floor |
| Thirteenth floor (high-rise transition) | 2 |
| Fourteenth to twenty-third floors | 1 per floor |
| Twenty-third, executive lift | 1 |
| Ground floor, fireman’s service lift | 1 |
Eight cameras on one floor, and one each on ten floors above it. The ground floor received as much coverage as the entire upper third of the building.
Why the bottom of a building eats the budget
Because that is where the decisions happen.
The ground floor is where everyone enters and leaves, where visitors are received, where deliveries arrive, where the lifts are boarded, and where somebody who should not be in the building is still deciding whether to go up. It is also the only level where a person can be seen before they have chosen a floor.
Once someone is on the eighteenth floor, the useful questions have already changed. You are no longer asking who they are — ideally you know that from the ground floor — you are asking when they arrived and where they went. One well-placed camera at a lift lobby answers that.
Coverage follows decision points, not area. A floorplate of identical size can need eight cameras or one, depending on how many meaningful choices a person can make while standing on it.
The lift lobby is the real target
Notice how much of that schedule is lifts rather than floors: the parking lift lobby, the executive lift, the fireman’s service lift, and one camera per floor which in practice means the lift lobby on each.
There is a reason. In a tower, the lifts are the corridor. Almost nobody walks between floors. If you cover the lift lobby on every level, you have effectively covered every route through the building, because the vertical circulation is a chokepoint that stairs cannot practically replace.
That is why one camera per floor is not stingy. It is the highest-value single camera that floor can have.
The specific lift types matter too:
- The parking lift lobby is the second entrance, and often the less controlled one. Three cameras there is not excessive — it is treating it with the seriousness of a main entrance.
- The fireman’s service lift provides access outside normal control, and it exists precisely for situations where normal control has broken down.
- The executive lift on the top floor serves a restricted destination, so who uses it is inherently a more meaningful fact than who uses a general lift.
The transition floor
One detail in that schedule is easy to skip: the thirteenth floor gets two cameras where its neighbours get one.
Tall buildings are frequently split into low-rise and high-rise lift banks, with a transition level where the two overlap. That floor has two lift lobbies rather than one, so a single camera cannot see both. Anyone changing between banks passes through it.
It is exactly the kind of place a design produced from a floor count rather than a site walk will get wrong — and exactly the kind of gap a person who knows the building will use.
What else the schedule fixes
Three decisions in that requirement carry as much weight as the camera positions.
Mirrored drives. Two hard drives configured as a mirrored pair, so a single drive failure does not take the footage with it. On a building this size, footage is evidence for dozens of tenants, and a single-drive recorder makes all of them dependent on one component with a known wear life.
Where the equipment lives, and where the operator sits. These are separate decisions. The recording equipment sat in an office on the first floor; the monitor sat at the security desk on the ground floor. Putting the recorder behind the security desk is convenient and wrong — it is the first thing someone removes. The person watching and the thing recording do not need to be in the same room, and usually should not be.
Feeds reticulated off site. All cameras fed back to a server at the owner’s separate offices. That is one of the few genuinely robust answers to the “what if the recorder is taken” problem, and it also means the people who need footage most — the property owner rather than the tenant — can reach it without attending the building.
Estimating a building you have not walked
If you are trying to sanity-check a proposal for a multi-storey building, this is the shape to expect:
- Entrances get the most. Every point where the public becomes a visitor. Count the entrances honestly — parking is one.
- Vertical circulation gets one per level. Lift lobbies. This is the backbone.
- Transition and plant levels get more than their neighbours. Anywhere the building’s logic changes.
- Restricted destinations get their own. Executive floors, service lifts, server rooms.
- Typical office floors get very little. Tenants secure their own suites; the landlord covers the common route to them.
A proposal that offers one camera per floor evenly, top to bottom, has been produced from the drawings without anyone standing in the ground-floor lobby at five o’clock.
The short version
A twenty-three storey building does not need twenty-three cameras, and it does not need one per floor. It needs heavy coverage where people make decisions, a lift-lobby view on every level, extra attention where the building’s own logic changes, and a recorder that is neither in the room being watched nor dependent on a single drive.
Count the decision points, not the floors.
Based on a requirement-stage camera schedule recorded for a 23-storey commercial tower in Durban, 2015. The building, its owner and the contractors are not identified. This describes what was specified at requirement stage, not an as-built installation; design any real building against its own layout and use.