Once upon a time, I lived in a rented flat in a leafy – and ridiculously gated –Dublin 4 complex. Despite the gate and the fancy address, my flat was broken into twice in three months with the ne’er-do-well making off with my telly on his – or her – first visit and all my CDs on the second. More than 15 years on, I still mourn their loss.

The flat wasn’t alarmed and the garda who investigated the break-ins said if it had been, the robber may have been deterred: the implication being that it was – sort of – my fault.

Fast forward 20 years to the present day. A long-since decommissioned security alarm on an exterior wall of my house started blaring in the dead of night. The keypad which should have been used to input a code – if anyone knew what the code was – had disappeared years earlier so all I could do was to stare at the shrieking box and ring random security firms looking for help. There was none forthcoming.

Hours passed until, eventually, roofers working nearby took pity on my ears and ripped the alarm from the wall. For over five hours the siren’s call attracted no police attention; only scowls from neighbours and howls from my dog. And two rough-looking (but lovely) men ripping the box off the wall did not see the Garda rush to the scene of the chime.

So the only thing the alarm did was ruin my night’s sleep which raises an obvious question? What is the point of house alarms? Do they keep us and our stuff safe? And if the answer is no, what can we do to keep the burglars at bay?

"The only thing an unmonitored alarm has going for it is the nuisance factor," says Colm Daly, the chief executive of HomeSecure, an Irish monitored alarm start-up currently locked in a David and Goliath struggle with market leader Phonewatch.

“Other than that there’s absolutely no value to them. To be honest, a thorn bush around your house or a dog barking would be just as good a deterrent, if not better.”

The uselessness of a shrieking box on the wall is what makes monitored services so attractive. Phonewatch is the most recognisable brand in the State although, despite what you might think, it is no longer in Irish hands after being sold to Sector, a Scandinavian company, in 2013.

Once the sale was completed, prices climbed, with the monthly service charge of €25 rising to €35 and then €37. On top of that there is an installation fee of €499. So it is not cheap but it does offer more protection than an unmonitored bell. When there is an alarm activation it goes to the Phonewatch monitoring centre which first tries to make contact with a homeowner, and then with their designated contacts.

If it can’t, the service rings the Garda who will – resources permitting – come out and see what’s up. Homesecure.ie also offers a monitored service but the upstart start-up does it for less and it comes with some extra bells and whistles. It allows people to set up external perimeter alarms while still in their home; many other monitored alarm services have only an on or off option.

It can also be set up to control lights and thermostats and can be programmed to talk to your mobile phone to keep tabs on your movements. So, if you are returning home from a holiday, the system will know when you’re 10km from your front door and turn on the heat, Daly says. “Then when you’re 2km away it could turn on the kettle and when you are 200m from your house it could open the gates.”

Mind you, you’d need a house with gates for that and only high-net worth people live behind gates.

And if you are a really high-net worth individual, a box on your wall that no one will heed or even a monitored smart alarm with nattily deployed DIY cameras streaming footage of your home and turning on your lights and boiling your kettle will be of little interest. You will need more.

This is where Thomas Gaffney comes in. He makes home bunkers to keep people safe from armed intruders and natural disaster or acts of terrorism. He does most of his business in New York City but as his name suggests, he is Irish; from Ballaghaderreen, Co Roscommon, in fact.

He is the chief executive of Gaffco Ballistics now but when he left home for America in 1985 he was a humble plumber. His first step away from plumbing was when he was asked to build a bulletproof steel cage for his cousin’s cheque-cashing company.

"They are like the poor people's banks," he explains. "There are areas like the South Bronx or Harlem where banks are scarce. So where can people go to cash their cheques? Where can they pay their bills? They use cheque cash houses but they need steel boxes and that's really what I started out doing."

Business was good and he moved on to securing retail banks with bulletproof glass and communications equipment. Then 9/11 happened and Fortune 500 companies came calling to see if he could install panic rooms in their headquarters. Then he moved on to the homes of these companies’ senior people. That now makes up more than 90 per cent of his business.

This year he will install dozens of safe rooms and while most of his work is centered around New York his business has an international dimension and he has worked in Dublin, Nigeria, Saudi Arabia and the UK. With a starting price of $150,000 (€133,000) and a top price of more than half a million dollars, his safe rooms are not cheap, but, if someone is spending millions on a home, the price tag can seem modest.

The installation is modest too. “What we do is line the walls and floors of the master bedroom with ballistic fibreglass – you might recognise the brand name Kevlar. And we reinforce the door. That buys people time if there is a house invasion. If they have an alarm service, they call the monitoring guys who call 911. It is a great short-term solution.”

He also sells a longer- term solution. “It is what I call the ‘sh*t hits the fan’ option. We take an area in the basement like a home movie theatre, secure it and put in an air-filtration system that allows the area to withstand a nuclear, chemical or biological attack. We get the food in, the water in and the iodine tablets.”

The top price for such a room is more than half a million dollars. "People will have spent as much of $60 million on their homes so the amounts we are talking about are peanuts compared with that," he says. He did an annexe to an embassy in Dublin not long ago. "I also priced up two other safe rooms for individuals in Dublin. We have done a few in Singapore, Nigeria and London."

The people he deals with “typically have their own security detail and are travelling a lot and maybe they have a wife and children at home. The good thing about it is you do not have to give up any space in your home. We just customise it. You wouldn’t even know the rooms were there, most of the time.”

The walls can survive an attack from an AK-47. “Remember, you can buy assault rifles in Walmart in the US. I still find that absolutely incredible.”

Gaffney says he would love to come home and do a bit more. “A lot of my contractors and other people with me are Irish. And my nephew looks after the engineering work and does all the computer-aided design from his office in Kilkenny.”

There are other options for the super-rich, such as the Overwatch system. Launched last month, the global service promises to track and monitor subscribers with a “discreet app enabled by cutting-edge and highly confidential technology”.

If you find yourself in trouble all you do is activate the app and a highly trained intelligence expert – think Liam Neeson in Taken – will find you. It was set up by DS-48, a London based provider of "bespoke intelligence-led risk management, advisory and resolution services".

"With global threats at an all-time high, we best ensure the safety of our clients discreetly and unobtrusively; providing peace of mind for them and their loved ones through an on-hand team of intelligence analysts and crisis managers led by highly experienced former special forces and intelligence officers," said company chief executive Charles Andrews when the new service was launched.

If you don’t have that kind of cash you might have to make do with a DIY deal. The Smart-Series from Swann features four weather-resistant, HD-wired cameras with 80-degree viewing angle and night-vision that works up to 100 feet away and allows you see clear video footage of activity in and around your home.

The makers promise it is "smart-home compatible" so you can connect it to other devices including Philips Hue Lighting, Samsung SmartThings, and Nest Thermostats.

There are also window and door alarm sensors to warn you if movement is detected and you can set them to trigger an outdoor siren with flashing lights which, if nothing else, will freak out would-be burglars.

You can buy a starter pack online from the US for no more than $500, although you will have to pay someone to set it up unless you are pretty handy.

Security cameras can be bought for as little as €100 and will stream footage to an app on your smartphone and send you updates when rooms are entered. They are great, if a bit creepy, and the value of getting a text alert warning you that your house is being burgled – complete with a live video stream – while you are sitting on a beach in Spain is questionable.

There is also the Burglar Blaster, which sells on US-based websites for $780. This is a movement-triggered dispenser of pepper spray which will fill a 185-square-metre space with choking, burning gas.

Once this alarm is triggered you have 40 seconds to shut it off. So you had better not install it in your home if you plan to stumble in drunk any time soon.

Alarm bells: How best to protect your home

Burglaries cost Irish homeowners about €30 million every year and despite the fact that we all know the risks, far too many of us make it far too easy for criminals to simply help themselves to our stuff. So, with that in mind, here are some dos and don’ts to help keep your house safe on the cheap.

Don’t think you live in some class of rural idyll where nothing bad happens. Secure all doors and windows and by that we mean lock them. A worrying amount of Irish people forget this basic rule and allow burglars waltz into their homes.

Do remember that thieves are opportunists and if they see an open door or an open window or another easy way to access your home, they will take advantage of it.

Jewellery, cash and small electronic items are the most commonly stolen items because they are easy to flog, so don’t just leave them lying around. If you are going away, conceal the stuff you value.

Do get a monitored house alarm fitted. Your aim is to make your house less attractive to burglars than your neighbour’s.

Don’t keep large amounts of cash at home.

Do bear in mind that one-third of burglaries take place between 5pm and 8pm, while one in 10 break-ins occur overnight. Many of them happen while victims are at home so make sure the alarm is on even when you are at home, particularly at night.

Do have your lights on timers so they go on and off while you are away. Serious criminals put time and effort into working out which houses in a neighbourhood are an easy target. Don’t make their job easier by leaving the lights off while you are away. Leaving a landing or bathroom light on is not much good, as even a dim-witted criminal will be able to see through this ruse.

Do not leave keys close to the letterbox. Criminals frequently “fish” car and house keys from hall tables. About 200 cases of car keys being “fished” through letterboxes are reported to the Garda each year.

Don’t grow tall hedges around your windows. Apart from the fact that they block out light, they also make it easier for criminals to access your home unobserved.

Do get yourself some exterior lighting, ideally with a motion-sensor floodlight.

Don’t dispose of the cardboard box that contained your €2,000 telly in plain sight.

Do get a dog. And it doesn’t have to be massive. Its bark is a whole lot more important than its bite, as its main job is to signal to the burglars that they will be bitten if they come into your house.