I worked FIFO for years before I went out on my own, so I know how the house feels from a camp two thousand kilometres away. The worry is not the telly. It is that your wife and kids are in that house on their own, and at two in the morning there is nobody for them to turn to.

Nearly all alarm advice is written for a family that is home every night. This one is for the other roster, and it covers the four ways it actually goes: a family at home without you, a place that sits empty for three weeks, an apartment, and the shed with something expensive parked in it.

What the alarm has to do while you are away

Four things, and none of them are what the brochures lead with.

The panic button is the part that earns its keep

This is the device I would fit first for a household on a roster, and it is the one people never ask for. The Ajax Button is a single wireless button. It can be worn on a wrist or round the neck, hung on a key ring, taped to the side of a bedside drawer or dropped into a wall holder at the top of the hallway.

What makes it useful at home alone is that it does not care what the system is doing. Ajax state that pressing it in panic mode raises an alarm regardless of the security mode, so it works whether the alarm is set or switched off for the day. Ajax also state that a panic press notifies every user on the system within seconds, which is the whole point for you: your phone lights up at camp at the same moment the siren goes.

It does not go through the phone, either. Ajax are specific that the buttons and key fobs operate independently of the mobile app, so a flat phone or a child who has never opened the app changes nothing.

The practical details that decide whether a family will actually use one:

The key fob has a panic button on it too, so a fob clipped inside the front door does the same job for whoever is closest to it. If you want it on the wall in a fixed spot, a keypad can carry the function as well.

Put more than two phones on it

This is the bit FIFO households get wrong, and it costs nothing to get right. Because an alarm reaches every user on the system, the question is not whether you get told. It is who else does.

A man on a two and one roster cannot do anything from site except make phone calls. So add the people who can walk round in ten minutes: your mother in law, your brother, the neighbour your wife would knock on anyway. They go on as users, they get the same alert at the same second, and nobody has to remember a phone number while something is happening.

What happens when the power or the internet drops

Every checklist you will read puts cellular backup near the top, and it is right to. It is also the thing a salesman will raise before you ask, so here is what it actually amounts to on the system I fit.

The hub in all three packages is the Hub 2 (4G). Ajax have it connected to three internet providers at once: the Ethernet cable to your modem, and 2G, 3G and LTE through its own SIM. Ajax state that switching between those channels takes seconds. In plain terms the modem can die, or the nbn can go down in the street, and the alarm still has its own way of reaching you.

It carries its own power as well. Ajax rate the hub battery at up to 15 hours with the Ethernet connection disabled, which covers the sort of blackout that has the family looking for candles.

If you want a second fixed connection rather than a cable on its own, the Hub 2 Plus upgrade runs four channels: Ethernet and Wi-Fi to two separate internet services, with two SIMs behind them. That is $150 on top of any package, and the honest answer is that most houses do not need it.

Tamper is the one people forget to ask about. The hub body is protected against being opened or pulled off the wall, and an attempt at it notifies you instead of quietly killing the alarm.

Where I disagree with the usual FIFO advice

Every list of this kind leads with remote app control: arm it, disarm it, check the doors from camp. That is real and you will use it, and the system does all of it.

It is still the wrong thing to put first for your household, because you are not the one in the house. The people who are in it need something that works with no phone in their hand at all. That is why I would spend the first $75 on a button before anything clever. Judge the system on what your family can do with it at two in the morning, not on what you can do with it on a crib break.

Setting it with the family inside

An alarm that can only be armed when the house is empty is half an alarm for your household, because your house is rarely empty while you are gone. Ajax has a night mode for exactly this: it arms only the detectors you nominate, so the doors and the perimeter are live while everyone sleeps inside and nothing trips when somebody gets up for a drink.

It is off by default and each detector has to be told to take part in it, which means it is an install decision rather than something a customer stumbles on later. Tell me the household sleeps there alone half the year and I will set it up that way on the day.

Where the detectors go in a house with people in it

My rule for a 3x2 or 4x2 is three to four motion detectors as a minimum, and they go in the common areas and the entry points, not the bedrooms. An intruder does not stay in one room. He moves through the house, so covering the walking routes catches him whichever door he came in by. There is more on sizing a system on the Ajax alarm systems page.

For a household on their own, I would weight it slightly differently to a family that is all home together: contacts on the doors that get used, so somebody inside knows the moment one opens, rather than everything pointed at the middle of the house.

If you live on your own and the house is empty

Everything above assumes someone is in the house. Plenty of us were not married, or not yet, and the house sat empty for three weeks at a time. That is a different problem and it needs a different system.

Nobody is there to press a button, so the panic button stops being the first thing to buy. What matters instead is that you can tell a real break in from a moth, because you are the only one who will ever look at the alert and you are a long way from the front door.

That is what the MotionCam detector is for. It is a motion detector with a camera in it, so when it triggers it sends photos of whatever set it off. Ajax rate the first photo at nine seconds. It has HDR so the image is not a white blur or a black one, pet immunity if you have left a cat with a neighbour coming in to feed it, and a battery Ajax rate at up to four years.

It is $300 supplied and installed, which is the most expensive detector on my list and the easiest one to justify for an empty house. One of them covering the main living area turns every alert you get at camp from a guess into a decision.

Two honest limits, because this is the part people assume wrongly:

One more thing that matters when nobody is home to notice anything: the hub tells you if it is being jammed or if it loses contact with a detector. An empty house means nobody would otherwise spot a system that has quietly stopped working, which is the failure that would actually cost you.

Apartments

Plenty of FIFO workers are in an apartment rather than a house, for the obvious reason that a place you lock and leave suits a roster. The system is the same, the layout is simpler, and the price starts lower: the Apartment Security package is $1,280 and covers the entry door, one living area and a key fob.

Three things are different and they all come up on site rather than on the phone.

The shed, and what is parked in it

This one gets left out of every alarm quote I have ever seen, and for a lot of FIFO blokes it is where the real money sits. A car worth more than the contents of the house, a bike, a boat, a trailer full of tools, sitting in a shed at the back of the block for three weeks while you are away.

The shed goes on the same system. There is no second hub, no separate app and no second subscription, because the radio reaches it: Ajax put the hub's network at 2,000 m and say it covers separate buildings, and the detectors are rated to 1,700 m for a MotionCam and 2,000 m for a door sensor, all in clear air. A brick wall and a tin shed cut that down, which is what I check on the day rather than guess at.

What usually goes in:

The part worth knowing is that the shed can be its own security group. Ajax hubs support nine of them, so the shed can stay armed around the clock while the house is disarmed and people are walking in and out. Your car is covered on a Sunday afternoon, not just while you are on swing.

Why a shed needs outdoor sensors on the inside

This is the part I have never seen in anyone else's quote, and it is the difference between a shed alarm that works in February and one that does not.

Ajax rate their indoor detectors from -10°C to +40°C. That covers the MotionProtect, the MotionCam and the DoorProtect alike. Ajax go further in the MotionProtect manual and list rooms with temperatures outside the permissible limits among the places not to install it.

Now think about a closed shed in Perth in February. We pass 40°C outside often enough, and a shut tin shed is hotter inside than the yard it stands in. The detector is sitting above its rated ceiling for weeks at exactly the time of year the place is shut up and you are away.

So in a shed that cooks, the gear that goes inside is the outdoor-rated gear, and not because of rain:

They cost more than the indoor versions and this is the one place I will argue for spending it, because an indoor detector in a hot shed is not a saving. It is a device working outside the range its maker publishes, in the building with the most valuable single thing you own in it.

The door contact needs the same thinking, and here Ajax leave a gap: they make no outdoor-rated opening detector, so DoorProtect and DoorProtect Plus stop at +40°C with the rest of the indoor gear. The way round it is the Ajax Transmitter, a small module that brings any wired contact into an Ajax system, rated to +50°C, wired to a plain magnetic reed switch on the door.

That splits the problem in two, which is the whole trick. Only the reed switch sits up on the hot door track, and a reed switch is a sealed lump of glass and metal with no battery and no electronics in it to cook. The module itself goes in a junction box wherever the shed is coolest, down low and out of the sun. It is quoted rather than published, because unlike everything else on the list it takes an enclosure, a reed switch and a run of cable between the two.

If you want it monitored

Ajax supports a monitoring company if that is what you want, and I can set the system up to report to one. That is your call to make, not mine.

What it costs

Installed Ajax packages start at $1,280 and every package and device price is published, so you can price the job before you speak to me. A Button is $75 supplied and installed, the same as a key fob. There is no monthly charge for the app and no contract: the system is yours, which matters when the thing you are buying is meant to outlast several rosters.

All of it is on the Ajax alarm systems page, and if you want the wider picture first, what an alarm or CCTV system costs in Perth covers cameras as well.

A job where the button was the whole point

I fitted this exact arrangement in Armadale for a client living alone, with the panic button linked through to the family phones so they know straight away if it is ever used. Different household, same mechanism as the one above. The write-up is here.

Where to start

Put a system together in the Ajax configurator and send it over, or tell me the number of bedrooms, whether it is single or double storey, and how long you are away at a stretch. A wireless Ajax system can normally be priced without a site visit.