Yesterday, Nutech Security's new office at 778 Cameron Rd, near Tauranga Hospital, was officially opened by Mayor Stuart Crosby. The company has taken over the refurbished house previously leased by Nexxus Financial Group - after moving from Waitomo House in Hull Rd.
"We are in a less-threatened place," said Mr Margan, who started Nutech Security with his wife Doreen in 1985 in Cambridge.
"I guess 18 months ago I became more aware of the danger posed by tsunamis. It got me thinking. We monitor thousands of alarms around the country - security, fire, medical, industrial and environmental (for chicken growing) - and if we are knocked out by a wave and our infrastructure is under water, then we wouldn't be able to function," Mr Margan said.
"People have always considered a tsunami like a surf wave. But everyone has seen the dramatic footage on television from the Japanese tsunami; whole ships and houses floating along. It brings home how huge these events can be.
"It's not just a wave, it's a huge rising of the ocean that comes ashore with immense weight behind it," he said.
"I hope nothing like this ever happens here, but you have to be prepared for the worst and hope for the best. It's like health and safety, once you become aware of the [geographical] hazard, then you have to take steps to minimise the risk.
"Moving was one way of doing that. Civil Defence is developing evacuation plans around the coast of New Zealand, and we wanted to play our part by helping out in an emergency," said Mr Margan.
Nutech co-ordinated the security arrangements during the big Tauranga flood in 2005, and afterwards joined the council's city partners programme.
Mr Margan said his company could provide manpower and technical services in the event of an emergency.
"We can supply guards to assist with an evacuation and to help hospital staff with security. We can have a technical team on standby to make sure the street cameras [CCTVs] are operating, and are maintained so the emergency management committee can see what is going on in certain areas.
"But it's like everything, what is the city's response to an emergency? There needs to be a plan," said Mr Margan.
Brought up in Cambridge, he completed a painting and decorating apprenticeship with his father Ray, drove trucks around the Waikato, built relocatable classrooms for schools, and worked at the Kinleith pulp and paper plant before falling into the security business
"A friend of mine said he had four weeks of work for me at Kinleith - I stayed there six and half years insulating pipes and vessels. I did another contract at the Mount insulating oil and turpentine tanks before coming home.
"I passed a security car doing a night patrol in Cambridge and I rang the guy up to say I was interested in that work," Mr Margan said.
"We had a chat and the next thing is he was selling the business to me."
It was called Checklock Security and he renamed it Nutech, and expanded into alarm monitoring as well night patrol.
"We would get a call (from the monitoring company) half an hour after an alarm went off. I figured that if we were going to be useful and provide a deterrent, then we had to act quicker than that. So I bought an alarm receiver and moved into monitoring," Mr Margan said.
He also extended his business to Hamilton in 1992 and then to Tauranga in 1995, starting patrols here three years later. The Margans finally moved to Tauranga in 1999, settling into the office on the corner of Chapel and Marsh streets and selling their Cambridge and Hamilton operations.
Over the past 16 years, Nutech has more than tripled its staff, from 10 to 32 full time, plus other casuals when security guards are required.
Mr Margan bought another business, Alarm Systems Logic, in Rotorua and Nutech has been monitoring alarms there since 2005. In the past four months, it has added night patrols and security guards.
"We are always looking to grow but not just for growth's sake," he said. "We've concentrated on a personal level of service and providing solutions. If someone rings at 2am it is answered by an operator, not a machine.
"The person ringing for the first time makes the remark: 'You are real'. I will keep the personal service, and anyway I don't like machines," Mr Margan said.
Nutech has a fully-secured monitoring room in its Cameron Rd office, staffed by three operators during the day and two at night. They are using the latest computerised technology.
Mr Margan, right now, has a particular campaign. Smoke detectors. "They are so cheap to put in. The modern alarm system is basically a computer programme and you get a lot of benefits if it's programmed properly.
"We monitor a lot of homes and when the smoke detector is connected to the alarm system which activates, the detector never turns off. It's all about being prepared," he said.