Demographer Mark McCrindle says Sydney will top seven million people, making it the size of London. Melbourne will almost double in size to seven million (with a population rivalling Hong Kong), and Brisbane will be the new Los Angeles, doubling in size to four million.

Our cities and way of life will almost be unrecognisable.

"At the same time we're going to see the costs get out of reach for many," Mark said.

• Home ownership getting harder
• The cost of the kids
• Rogue tradies

Demand for cheaper, more energy efficient and quicker-to-build homes is set to sky rocket.

Property expert Terry Ryder says our love affair with the McMansion can't last.

"Globally Australia now has the largest houses in the world. Previously it was always the Americans who built the biggest houses, but in the last year Australia's actually over taken them."

"Developers are telling us that we have a problem that people can't afford to buy new houses anymore, but I believe that a major part of the problem is they keep pumping out these McMansions when the demographics are demanding much smaller houses," Terry added.

Mathew Liddy from Australian Property Investor Magazine says Australia faces a real challenge if housing for another 20 million people is needed.

"I think it's caught some people by surprise that Australia is now having a mini baby boom," Mathew said.

"The consequences of that sort of population growth will depend on how we deal with it."

But some forward thinkers are providing an alternative - the homes of the future are made in a couple of weeks, in a factory and erected in two days. They're energy efficient and start at $150,000 dollars, for three bedrooms and two bathrooms.

"People will still want their excessive houses, but there is a massive part of the market, 7 million Australians, who in the last 50 years have been ostracised from the building market. This is the kind of house that those people need," said Brett Blacklow, the designer behind the modular homes.

These homes can accommodate even the largest family by simply adding more modules. Built by Ausco for the Mining Industry, they'll soon be available in suburbia.

Joe Evans is the first residential developer to take these modular homes to the retail market, with his 18 townhouse development at Redbank, west of Brisbane.

"They're a really good design, they're environmentally sustainable and they're affordable, really good quality product," Joe said.

And while it may seem they're built like a house of cards, they don't fall down like one.

"The house would last at least as long, if not longer, than a traditional brick and tile house - it is fully cyclonic," Joe said.

Shipping containers too are fast becoming a building material of choice being transformed into modern homes. In Europe they are even used to build unit blocks and its not just the budget conscious looking to factory built homes.

"Typical architectural homes will be $3500 to $4000 a square meter to build," said Toby Lewis, founder of Happy Haus.

Happy Haus are homes built in a factory then constructed on site, in a matter of days.

"I think we're facing a housing revolution for sure,"Toby said.

One construction takes up a prime position on the Gold Coast beach front and it took longer to do the landscaping than it did to build the home – it was erected in two days, at half the cost.

"I think developers and builders around Australia are trying to find ways to be smarter, build more quickly, be much more echo friendly, so I think the old days of filling the streets of 20 utes for nine months are gone," Toby said.

Links and information

www.apimagazine.com.au

www.happyhaus.com.au

sales@ausco.com.au