Many renters would be nervous about putting a nail in the wall, let alone a pool in the yard.

But Andrew Robertson has signed no ordinary contract.

"We've bought the house but not bought the house," Mr Robertson said.

The Gold Coast father has entered a rent-to-buy agreement, meaning if all goes to plan, he will one day own his home.

If he had gone to a bank, Mr Robertson would have needed a deposit of around $150,000 to purchase the house at Pacific Pines.

Instead, he paid around $36,000 to one of two rent-to-buy companies that have launched in Queensland in the past year.

"It's been fantastic for us," he said.

"Trying to save up and rent at the same time — the way the property market keeps rising — it's quite hard to keep track of where you need to get to.

"We would have aimed for a certain amount of deposit for a certain property, but by the time we got there, that deposit required for that property would be higher again."

An academic warns that the rent-to-buy model, billed as "new path to home ownership", is risky because prices are locked in regardless of how the market behaves.

"Buyers need to be very conscious of what they are signing up for," Professor Shaun Bond from the University of Queensland's business school said.

How do rent-to-buy contracts work?

As the name suggests, you rent a home with the option to eventually buy it.

The companies buy the property, and the customer pays them a smaller than usual deposit.

In Mr Robertson's case, the up-front fee was 3 per cent of the house's agreed value.

The customer then pays an ongoing fee, a bit like rent but also covers utilities. Part of that fee is saved as equity in the home.

Once enough equity is accrued, the customer gets a regular home loan, and the property title is transferred to them.

James Bowe, the co-founder of OwnHome, said the model is designed to allow people to save for their home while living in it.

"What you are doing is locking in the price that you can buy that property back," Mr Bowe said.

Dean Arnold, the founder of PublicSquare, said the agreement was like a "forced saving mechanism" that would help buyers get into their own homes "up to 10 years earlier".

"We like seeing our customers building up at least 2.5 per cent a year in equity, which means by year four they have 10 per cent equity ready and they can get onto a traditional mortgage," Mr Arnold said.

What's the catch?

If the property market goes down, you could end up paying more for the house than its worth, Professor Bond warned.

Under the contract, the agreed price of the property increases each year — with OwnHome, 3.8 per cent per annum.

"Prices are actually starting to fall again so buyers need to be very conscious about locking in future price increases when we are clearly past the peak," Professor Bond said.

But Mr Bowe said historically prices have always increased in the long term.

"We certainly don't have a crystal ball on how property markets are going to play out," he said.

"What we have seen over the past century is that there's never been a seven or 10-year period in which house prices have ended up lower than they were at the beginning of that seven to 10-year period."

Mr Arnold admitted a downturn, or rise of less than 3 per cent a year, would be a "financial downside" for customers.

He said however that his company's customers were in it for the long haul.

"They're not really thinking about what's the market going to do over three or four years," he said.

"They're thinking about I'm going to live in this home for 10 to 20 years.

Mr Robertson said based on the historical prices in his suburb, he was not "overly concerned" about prices falling.

"But it's obviously in the back of your mind," he said.

How do the payments compare to regular renting?

"They're quite a bit higher," Mr Arnold said.

"But imagine if you were serious about building $100,000 or more in deposit within 10 years, you're going to have to save hundreds of dollars per week on top of rent."

Mr Robertson said his ongoing "rent-to-buy" payments were less than the rent he was paying previously.

"For us in that respect, it's not any different financially, except this time we're going towards our own home rather than someone else's mortgage," he said.

Mr Bowe said his company's ongoing charges included water rates, council rates, maintenance, and repairs.