Millionaire and budding property magnate Johnathan Brownlee isn't your typical 21-year-old.

He owns 11 properties valued at more than $3 million across New Zealand, from Auckland down to Invercargill.

Brownlee's created $1m in equity and expects to pull in more than $60,000 per year in after-expenses income once he finishes his next renovation.

His parents topped up his savings to reach the threshold for the initial deposit for his first property in Hamilton, but his entrepreneurial spirit from a young age helped him get to where he is today.

Brownlee imported goods through China's Alibaba website and onsold them through Trade Me while in high school to build up his savings.

His interest in property was sparked after a guest speaker at university introduced him to the concept of leverage and using the bank's money to pay for a high-value asset, like a home.

But it wasn't just the speaker's words that caught the attention of 18-year-old Brownlee.

"He was driving something like a new Bentley and that was my lightbulb moment," Brownlee said.

"I realised that there is a snowball effect with property, so the sooner I could get into it and get investing, the better off I would be in the long term."

Brownlee's story of carving out a housing empire at a time when many young people feel shut out of the property market will either give millennials hope, or make them weep.

Regularly ranked one of the world's most unaffordable cities, many Auckland suburbs have more than doubled in value since 2007's last market peak, while prices in many other parts of the country have jumped by at least 40 per cent.

For Brownlee, the trick was to look outside his home city of Auckland and first buy in Hamilton.

Brownlee poured all his savings from his importing job into the deposit, while his parents picked up the rest and guaranteed the loan on the proviso they would be paid back everything they put in.

Then Brownlee sat on the Hamilton home for six months, before getting it revalued.

Finding it had already gained substantially in market value, he used the increase in equity to ask the bank for a new loan for another property.

From there he moved quickly, emulating the strategy of buying homes "below market rate" and making renovations before getting them revalued so he could then borrow on the difference as soon as possible.

He was able to buy his second property at 19 and owned five by the time he was 20 years old.

Now he has 11 properties in Wellington, Hamilton, South Auckland, Hastings, Dunedin, Masterton, Whanganui and Invercargill - having chosen to hold onto all of them rather than sell.

His parents - both accountants - helped with financial guidance, but Brownlee said the grunt work and passion has always been his.

He remembers driving home at 3am from Hamilton one night, having worked on his first property at the same time as doing a night shift in a call centre and studying at university.

"Surely, no one else is doing this," he recalls exhaustedly thinking to himself.

Soon he'll be putting in the hard graft again, spending up to three months living alone in a sleeping bag at his latest investment property: a fire-damaged home in Whanganui.

The west Aucklander will work alongside builders to strip the home back to its bare bones so that the roof can be taken off, the walls realigned and much of its framing rebuilt.

In addition to the physical work, Brownlee also spends hours reading "everything available on property", chatting to other investors, engaging in online property forums, keeping an eye on different markets and dealing "with hundreds of real estate agents".

However, not all his investments have been winners.

His decision, while at high school, to import a damaged BMW car from Japan with the idea of repairing and onselling it ended with a loss.

"[It] taught me how important it is to do a lot of research before making any investment decision," he said.

It's a lesson Brownlee believes has kept him in good stead and not fearing being caught in a housing crash with 11 mortgages to his name.

"I make sure that every property I buy, I'm buying below market value so I've got a buffer in there from day one," he said.

"And also I make sure that every property I buy is quite high cash-flow so it can sustain an interest rate increase and pay for all of its expenses."

His property portfolio has inspired a few close friends to buy their own properties by following his advice of getting in at the bottom of the market on houses as cheap as $40,000.

Most strangers simply drop their jaws in amazement when they find out Brownlee is just 21 and own 11 properties.

"How did you do it and how can I do it?" they nearly always ask.

Brownlee hopes to start passing on his advice to more people in the future, all while showing no signs of slowing down as he chase the goal of one day owning 100 properties.