The cost of the policy is $474 million over four years, which will cover $500 payments to property owners over four years to make small repairs to bring rental homes up to new rental standards. The Greens Rental Rights policy would: Establish a new national body responsible for overseeing a new national standard for all rental tenancies;

Develop a National Residential Tenancy Act;

Provide a funding package worth $500 per property to help landlords make upgrades to meet the new standards; and

Increase funds to state and territory tenancy advice Services by $10m per year. Senator Waters said few people realised the extent of the rental market in Australia. "The private rental market is a critical part of the Australian housing system, with over one quarter of all Australians – almost two million households - renting privately," Senator Waters said.

"Overall that is around 26 per cent," she said. "The proportion of renters is even higher in capital cities, with 60 per cent renting in Sydney, 58 per cent in Melbourne, 48 per cent in Brisbane, 40 per cent in Adelaide, and 38 per cent in Perth." A survey of 3000 Australians – plus Australian Bureau of Statistics 2015 data – provided the background to the policy. Brisbane's two inner-city electorates – the seats of Brisbane and Griffith – both have high concentrations of rented homes. The Greens national rental survey shows 48 per cent of homes in the Brisbane electorate are rented, while 46 of the homes in the seat of Griffith are private rental properties.

Senator Waters will launch The Greens Renters Right's policy in Brisbane's Griffith electorate – which runs through the inner-city suburbs from Bulimba, Carina across West End to Holland Park. Coorparoo mum and law student Tegan McMahon, who said she had joined the Greens, told how rushed roof repairs to a previous unit at West End left her family, including a crawling toddler, exposed to the weather. Electricity was also turned off for eight hours a day for three days in a row. "None of the construction people cleaned after themselves. There were piles of roof left lying around. One night we didn't even have a roof. We could actually look through the ceiling and see the stars. Plumbing problems, I could tell you so much," she said. "We were contacting the real estate every day saying 'We just can't have this, but they weren't sympathetic. They didn't seem to care."

Ms McMahon said she was frustrated to hear the owner tell the builder not to make some rental renovations, "because we will only get about an extra $50 a week." "The builder said 'do you want to paint this door' – which was our door –and the owner said 'No, don't bother'," she said. Ms McMahon agreed it was time there was a national rental strategy. "It is just unfair. If you can't afford something a bit nicer, you are really left with what is left over." Senator Waters said the survey also showed about half of respondents spent half of their income on rent.

"With the average rent for a two-bedroom unit in Brisbane now at $470, it's not surprising that renters are having to fork out so much of their income on rent," Senator Waters said. Senator Waters said high rents prevented people saving to buy a home. "An increasing number of Australians now see renting as their only option, and believe they'll become renters for life," she said. She said some Brisbane renters were afraid to report problems because they were afraid their leases would not be renewed. "Compared to other countries, Australia has some of the weakest protections for renters – it's high time we improved the rights and conditions for Australia's renters."

Tenancy groups across Australia are understood to agree with the push for extra rental protections. For independent news coverage, be sure to follow our Facebook feed.