"None of us can stay, because none of us can afford that."

The days of being able to find a room in a Wellington rental for less then $200 a week are becoming a thing of the past, flat hunters say.

In November 2016 there were 1930 available rentals in the capital being advertised on Trade Me. This year, there were only 560, meaning rental availability had fallen 71 per cent.

The real winners are the city's landlords, who experts say could raise rents even more in 2018.

Head of Trade Me Property Nigel Jeffries said a two-bedroom property in the suburb of Mt Cook received 33 inquiries within the first three hours of being listed in November.

Wellington was a victim of its own success - a growing population and a good economy, he said.

"There's no sign that demand will tail off, so we need to look at increasing the supply of houses."

Jeffries said rents usually increased between $20 and $30 a week during January and February, and would likely be more in 2018.

Victoria University student Simran Rughani has been on a "stressful" search for a new flat since October, and has lost count of how many she has viewed.

Finding a room for under $200 a week was rare, she said.

Another student, who did not wish to be named, said her landlord decided to increase the rent of her 8-bedroom place in the suburb of Kelburn by $500, after splitting a large room into two.

Everyone living there was now paying about $230 every week in rent, she said.

"None of us can stay, because none of us can afford that."None of the flats she had viewed were less than $200 a week.

"I was living in Te Aro last year, and I was paying $190, but I was living in an outhouse."

Victoria University students' association president Rory Lenihan-Ikin said students were so tired of flat-hunting they were staying in their flats longer, enduring rent increases.

Landlords "taking advantage" of students were increasing rents up to $50 a week to match the recent student allowance increase of $50, he said.

Students would not come to Wellington if the struggle continued, he said.

"The only solution is to build more houses ... we're going to see this getting worse and worse."

Wellington landlord Anna Welch said she advertised one of her properties on Trade Me, and had no trouble finding tenants.

Some were "very desperate" to rent in the suburb of Newtown, she said.

In November, they had another property available but did not advertise it, except for telling people locally.

"People were stopping us in the street asking us if our place was still available."

Nice Place company director Keith Powell said the worst was yet to come, when students arrived in the capital "in bulk".

"Everyone is saving up their burst until after Christmas, and then it will go crazy."

More were re-signing their leases compared to last year, which was a positive thing, he said.

Bayleys Real Estate Wellington regional residential manager Grant Henderson said with more people moving to Wellington, more rooms were needed.

"No high-rises are being built, there's no more rooms being made, so we're behind the times."

Grant Foggo, director of property management company Comprende, said January movers had been securing property as early as October and November.

Wellington Central MP Grant Robertson said he was "very concerned" with the current state of the capital's rental market.

Pressures from the housing shortage had built up and were now affecting both the rental and first-home buyer markets, he said.

"This is why the Government has prioritised investment in house building through KiwiBuild and other initiatives in Wellington, as well as other parts of the country."

Victoria University campus and student living director Rainsforth Dix said university halls had an extra 240 beds for 2018 compared to 2017.

There were 15 students on a waitlist for 2018, she said.

"We encourage students who are concerned about getting a flat to contact the University's accommodation service early in the new year."

AVERAGE MEDIAN RENTS

* Auckland - $530

* Wellington - $470

* Marlborough - $420

* Christchurch - $390

* Hawke's Bay - $380

* Whanganui - $320

* West Coast - $288