How Many CCTV Cameras Do I Need for My Perth Home

Camera packs are sold in fours and eights because those are tidy numbers to box up. Your house was not designed around a box.

The number you need comes from how many ways there are onto your block and how many paths run across it. Every one of those wants a camera on it, and everything else is optional.

• The front door and the path leading to it
• The driveway, from the kerb to the garage
• Each side gate, counted separately, because plenty of Perth homes have two
• The rear boundary where it backs onto a laneway, reserve, park or oval
• The garage or workshop, if what is stored in there is worth watching
• Any second street frontage, which corner blocks always have

Write that list down before anyone starts talking about camera models. It usually comes out at somewhere between three and eight on a suburban Perth block.

Four is the number that suits a lot of standard single storey Perth homes, and it is worth understanding why rather than taking it as a default.

Those four cover the front, the back and the join between them. On a rectangular block with a fence, one gate and a single frontage, that is genuinely most of it.

Plenty of Perth blocks are not the standard rectangle, and the ones that are not tend to need six or eight rather than four.

• Corner blocks have two street frontages and usually two gates, so both sides need covering
• Battle axe blocks have a long driveway leg where a camera at the house cannot see the street end
• Two storey homes have upper level windows and balconies, and a longer perimeter at ground level
• Homes backing onto a laneway, reserve or park have a rear approach that a front camera never sees
• Big blocks in the outer suburbs put the shed, the boat and the side parking well away from the house
• Granny flats and studios at the rear are effectively a second dwelling with their own door
• Front fenced properties with a gate at the street want a camera at the gate as well as at the door

Long side runs are the other one that catches people out. A narrow path down the side of a double brick house is hard to cover from one end, because a camera at the front sees a corridor of fence and not much else.

Recorders come with a fixed number of camera channels, commonly four, eight or sixteen. That number is the hard limit on how many cameras the system can carry.

It matters most when you want to add a camera later. Four cameras on a four channel recorder leaves you nowhere to go, so a fifth camera means a new recorder as well as a new camera.

1. 1

   Work out the cameras you need now

   From the entry point list, not from a package. This is the number that has to be covered on day one.

2. 2

   Think about what might come later

   A shed going up, a pool, a granny flat, a gate camera. Anything already on the plan is worth allowing for.

3. 3

   Size the recorder above the current count

   If you need five cameras now, an eight channel recorder leaves room. If you need four and nothing is changing, four may be all you ever want.

4. 4

   Check the power budget as well as the channels

   Recorders that power the cameras down the same cable have a total power limit, and a full house of cameras can approach it.

5. 5

   Keep the cable path in mind

   Even where a camera is not going in today, knowing where its cable would run keeps the option open.

6. 6

   Get the count and the recorder in the same quote

   They are one decision. Quoting cameras without saying what recorder they land on is how people end up buying twice.

Every camera writes to the same hard drive. Add cameras and each one gets a smaller share of the drive, which means the rolling window of footage you can look back through gets shorter.

Resolution does the same thing. A higher megapixel camera gives you more detail when you zoom into a still, and it uses more space doing it.

• Recorders fill the drive then write over the oldest footage, so you always have a rolling window rather than a drive that jams
• Doubling the camera count roughly halves how far back that window goes, all else being equal
• Higher resolution and higher frame rates both shorten it further
• A bigger drive buys the window back, and drives can be sized to whatever retention you want
• Recording continuously rather than only on motion uses more space and never misses the first second of an event

The useful question is not how many days the drive holds. It is how long it might take you to notice something and go looking, because that is the window that has to cover you.

Adding cameras past the point where they are doing real work costs money, eats drive space and gives you more views to scroll past. Some are genuinely not worth it.

• A second camera covering the same path as the first from a slightly different angle
• A camera watching a blank side wall with no gate, no window and no way through
• A camera aimed mostly at a neighbour's yard, which is a problem in its own right
• A camera on a first floor balcony that overlooks nothing but your own roof
• Indoor cameras in rooms the household lives in, which most people stop leaving on
• A camera in a position nobody can get cable to, which ends up on wifi and drops out

Cutting one of those and putting the money into a better position or a bigger drive is usually the stronger result. We will tell you which cameras on a plan are doing real work and which are nice to have.

You can get close to your own number in about ten minutes with a walk around the block and a list.

Count the ways in. Add the paths between them that a person would have to use. Then ask which of those you would want a face from and which you would only want to know about.

When we quote, that walk happens with you, and you get the camera count and positions in writing before anything is drilled. If four does the job at your place, four is what you will be quoted.