Security Advice · CCTV
How Many CCTV Cameras Do I Actually Need?
Most people ask for a number and get sold one. The useful question is what each camera has to be able to show you – because that decides both how many you need and, more importantly, where they go.
The short answer
- Most Auckland homes are properly covered by 4 to 6 cameras, not eight.
- Count ways in, not rooms. A compact house with five external doors needs more than a large one with two.
- One camera has to be a tight face shot at the front door. Wide overview cameras cannot do that job.
- A 4K camera can only identify a stranger across about 15 metres of scene width. Wider than that and you get a shape.
- Four cameras placed well beat eight placed badly. This is the system we are most often called out to fix.
The number falls out of the questions, not the house
Before counting anything, work out what you would actually want to know after an incident. In practice it is nearly always the same four things: who came to the door, what happened in the driveway, whether anyone went down the side, and what vehicle was involved.
Each of those is one camera with one job. Once the list exists the count answers itself – and so does the placement, which matters more than the count ever did.
It is also why floor area is a poor guide. A three-bedroom house with a front door, a back slider, a side gate and a garage needs the same coverage as a much larger house with the same four ways in.
The thing nobody tells you: pixels per metre
There is an actual standard for this. Video surveillance is specified in pixels per metre across the scene, and the four useful levels have names – detect, observe, recognise, identify. They are not marketing words; they describe what the footage can be used for afterwards.
| What you need from the shot | Pixels per metre | 4MP camera covers | 4K camera covers |
|---|---|---|---|
| Detect – someone is there | 25 | ~100 m wide | ~150 m wide |
| Observe – what they are doing | 62 | ~40 m wide | ~60 m wide |
| Recognise – someone you already know | 125 | ~20 m wide | ~30 m wide |
| Identify – a stranger, usefully | 250 | ~10 m wide | ~15 m wide |
Read the bottom row carefully, because it is the whole article. A 4MP camera pointed across a scene 40 metres wide can tell you a person is doing something. It cannot tell you who. That single fact explains almost every disappointing system we are called to look at: the camera was fine, the scene was too wide.
So at least one camera has to be tight. A doorway shot two metres across gives well over a thousand pixels per metre on any modern camera – that is a face worth handing to police. The wide driveway camera is for context, and no amount of resolution changes that.
What most Auckland properties actually need
| Property | Typical count | The shots |
|---|---|---|
| Townhouse or unit | 3 – 4 | Front door tight, driveway, rear slider, side access |
| Standard 3-bedroom home | 4 – 6 | The above, plus garage and the second side |
| Larger or two-storey | 6 – 8 | Adds a second approach angle and any outbuildings |
| Lifestyle block or long drive | 6 – 8 | A gate camera set for plates, then the house cluster |
| Small commercial | 6 – 12 | Entry, till or reception, stock area, yard, loading |
Commercial numbers climb for a different reason: most of what a business reviews is a dispute, not a burglary, so the till and the counter matter as much as the doors. We size those against the site during a free site assessment – see commercial security for how those jobs run.
Where the cameras go
Low enough to see a face
The instinct is to mount high, out of reach. Mounted at three metres you get an excellent view of the top of everyone’s head. Around 2.5 metres, under an eave, is high enough to be awkward to interfere with and low enough that the camera is looking at a face rather than down at a scalp.
Pointed away from the sun, not into it
A camera facing west across an Auckland driveway is blown out every clear afternoon, in exactly the hours you care about. Where possible the sun should be behind the camera. Where that is impossible, the shot needs a camera chosen for backlight handling – a specification decision, not a mounting one.
Covering the approach, not just the door
A camera on the door records someone who is already at the door. A camera covering the path records the decision to walk up it – including the walk-past twenty minutes earlier that turns out to be the same person. That is what makes Ajax DoorBell useful: it has its own motion sensor, so it starts recording when someone approaches rather than when they press the button.
Inside counts too
One indoor camera covering the room a back door opens into is worth two more outside. The outdoor cameras tell you someone came in. The indoor one tells you what they took and which way they went.
The eight-camera trap
The most common system we are asked to improve is eight cameras, all mounted high, all set wide, all recording the same style of shot. It cost more than a well-designed six and answers fewer questions, because not one of the eight can identify anybody.
Fixing it rarely means more cameras. It usually means moving three of them lower and closer, and re-aiming two others so they stop overlapping. Which is worth knowing before you buy, not after.
A useful test before you sign anything. For each camera on the quote, finish this sentence in one line: “this camera exists to identify anyone at the front door” / “to read plates at the gate” / “to see the side gate open”.
Any camera you cannot finish that sentence for is one you pay for twice – once to install, and again in the storage it fills every day for the rest of its life.
Common questions
How many cameras does a typical 3-bedroom house need?
Four to six. A tight face shot at the front door, the driveway, the rear door, and each side access route. A sixth usually covers the garage or a second approach angle.
Is 4 cameras enough?
For most homes, yes, provided each answers a different question. Four cameras covering four entry points beat eight overlapping wide shots at a higher price.
Do more megapixels mean I need fewer cameras?
Only slightly. Going from 4MP to 4K widens the scene you can identify a face across from roughly 10 metres to 15. It does not let one camera replace three, because a camera still only points one way.
Where should the front door camera go?
Around 2.5 metres up and close enough that the doorway fills a decent part of the frame, angled so someone at the door is looking towards it rather than under it. A video doorbell often does this job better than a wall camera.
Do I need cameras inside the house?
One or two are worth more than people expect, typically covering the room a rear door opens into. Outdoor cameras record the entry; indoor cameras record what happened next.
Can I add cameras later?
Yes, provided the recorder has spare channels and the drive has room. It is worth buying an 8-channel recorder even for a 4-camera system for that reason – the recorder is the cheap thing to oversize.
Not sure what your property needs?
We walk the site, work out what each shot has to show, and quote the cameras that answer it. Free assessment, no obligation.