But as the Australian population lives longer it will also have to work longer over the next four decades, amid more sluggish economic growth and a huge spike in the number of people living to 100, according to the latest Intergenerational Report released on Thursday.

Edgar's mother Claire Fraser, of Braddon, said it was difficult to comprehend how different her son's adult life might be from her own in the 2050s.

"I guess I would hope that quality of life in terms of health would get better because people are becoming very aware of diet and exercise and how important that is," she said.

"I wonder just how unaffordable properties will become ... something's got to give."

Ms Fraser remained positive about her son's future but said it was hard to imagine her grandchildren living to 100.

The average life expectancy of an Australian woman born in 2055 will reach 96.6 years, up from 93.6 in 2015, while a man born in 2055 will live until he is 95.1 years, up from 91.5 years, according to the report.

The number of Australians over the age of 100 is expected to climb to 40,000 in 2055, up from about 5000 today.

The report also predicts tax relief to address "bracket creep" – people moving up into the next tax bracket through wage inflation – will be pushed back to 2021 when tax revenue as a proportion of GDP returns to the pre-global financial crisis level of 23.9 per cent.

"I don't really worry too much about things the way some other mothers do," Ms Fraser said.

"As long as people are healthy, I guess that's the main thing. People will end up having a longer working life. Some of it will also be a longer retirement, if they're retiring at 75 and living to 100."

One growing issue already affecting Edgar and other children his age in the capital was the demand for education, and its skyrocketing cost.

"One of the things that's been an issue already has been trying to get him into school, we've put him down for Radford and everyone I know who has a baby his age has done that. Even if he does get in, it's really expensive," Ms Fraser said.

"I imagine Canberra will grow and hopefully become a nicer place to live with all the government is doing with the lake regeneration."

Meanwhile, the report has already come under scrutiny for skimming over climate change. Labor gave the issue a chapter, 74 mentions and described it as the greatest threat to Australia's environment in its 2010 report. It receives 3½ pages in the 2015 document.

With Mark Kenny and James Massola