When Dr Kim Proudlove moved to Australia from Vancouver in 1997 she was glad to leave that city's homeless problem behind.

"Winter in a place like Vancouver which is slushy, dark and you're seeing people holed up on cement doorways ... I would not want to be homeless."

She said she was "amazed" by the lack of homelessness in Australia when she first arrived.

"There just didn't seem to be that disparity — there was a living wage; people cleaning your toilets and serving you coffee were making decent money."

But she said that had changed in recent years.

"Seeing people camped out under the bridges ... it's quite confronting in a way that it wasn't even seven or eight years ago."

Kim wondered, what has caused this recent and visible increase in homelessness?

Keen to know the answer, she asked Curious Melbourne, an ABC Melbourne initiative in which audience members submit questions they would like to see answered.

ABC reporters are regularly assigned to investigate the questions, and the person asking it is sometimes asked along to help with the story — like we did with Kim.

High demand for homeless services

ABC Melbourne took Dr Kim Proudlove (centre) to Launch Housing, a service which helps people experiencing homelessness. ( ABC Radio Melbourne: Simon Leo Brown )

To begin our investigation we arranged to meet Kim at the St Kilda office of homelessness charity Launch Housing.

"We're what's called an entry point," said Danielle Baldwin, a coordinator at the service.

"If someone feels like they are at risk of homelessness or they are experiencing a crisis, they would come to our service.

"Basically we just assess what the person needs and then we try and find that for them."

That could be anything, she said, from money towards rental arrears or establishing a new rental, to finding crisis or supported accommodation.

They also provide referrals to other services such as drug and alcohol, mental health, family violence or aged care.

A rise in homelessness over the past few years prompted Launch Housing to establish an outreach program targeting people sleeping rough in the CBD and surrounds.

Demand for Launch's services is high.

"This morning when you got here there were already five or six people waiting at 9:00am," Danielle said.

"We tend to, on average, spend about an hour with each person, so people that are coming in a bit later in the day may have a couple of hours' wait.

"As it gets towards the end of the day we do try and triage to make sure that everyone who has nowhere tonight is assisted with accommodation for at least tonight."

Danielle said she liked to think she could find help for anyone who needed it, but nationally the figures showed demand for these sorts of services outstripped supply.

Data from the Australian Institute for Health and Welfare (AIHW) reveals that on average 261 requests for assistance go unmet nationally each day, mostly due to a lack of available accommodation.

Launch Housing chief executive Tony Keenan said there were simply not enough beds to go around.

"The three big crisis centres are about 160 beds in Melbourne; that wouldn't even cover the amount of people rough sleeping in the CBD."

He said his service could mostly only offer short-term, stop-gap solutions such as a couple of nights in a motel.

Homeless attracted to Melbourne's CBD

John Kenney says many people sleeping rough are sick of dealing with crisis accommodation. ( ABC Radio Melbourne: Simon Leo Brown )

After leaving Launch Housing we jumped in a cab to Collingwood to visit the offices of the Council to Homeless Persons (CHP), the state's peak body for homelessness.

In the office kitchen, having a cup of tea, we met John Kenney, who first became homeless when he fled a violent home at the age of seven.

"When I first started out we used to have to live in the back of laneways underneath rubbish bins," he said.

"I lost a couple of mates through the rubbish bins, they actually were sleeping in them.

"The garbage [truck] came along the next morning, early in the morning and picked it up and tipped it in the back."

After 50 years of life in and out of institutions and on and off the streets, John now lives in supported accommodation but maintains friendships with people sleeping rough in the city.

He too has seen the numbers rise.

"The last five or six years, seven years, I've noticed a big increase," he said, adding that many people sleeping rough had given up trying to access crisis accommodation.

"As soon as they're in there, maybe a week, maybe two weeks, maybe a month, they're out again.

"There's no money for accommodation, there's not enough accommodation."

John said much of the city's temporary accommodation was only available to people under 21 or older than 50.

He knows at least one person sleeping rough who has a job but still can't afford rent, and another who Centrelink is demanding find work despite her not having a home.

Still, life on Melbourne's streets is easier than it once was, he said, with charities offering food, showers and other essentials.

"The only bad thing about being on the streets is that the police are still taking their gear off them."

Melbourne had become attractive to people experiencing homelessness, he said, and many of those involved in last year's Flinders Street camp were from interstate, as are many of the city's beggars.

"It makes the homeless people here look bad."

While many of those begging on the streets may be from interstate, others like Andrew McIntosh are from Melbourne. ( ABC Radio Melbourne: Simon Leo Brown )

Share housing not an option

John said that for most people sleeping rough, sharing a house with others was not on the agenda.

"Why should you have to share a house, to be honest? So you can argue and fight?

"How do you know you can trust that person's not going to grab your stuff and go?"

CHP chief executive Jenny Smith said people experiencing homelessness often did not have the personal skills or social networks required to live in a share house.

Today's heated housing market means there is greater demand for the lower end of the rental market.

"If you take a middle-class young couple trying to save for a deposit for a house, they are now more likely to rent something that is less expensive ... to try and save for a much bigger deposit for a much bigger mortgage," Jenny said.

"People on the lowest incomes ... are competing with people who can have references, support and subsidies from their social network, family, friends to better compete for that low-cost housing."

That's if they can find a low-cost rental in the first place; in recent years there has been a dramatic decline in the availability of houses people on a low income can afford.

"If you go back 10 years you could have expected that 25 per cent of the rental properties out there in greater metropolitan Melbourne would have been affordable to someone on our lowest income, the Centrelink income," Jenny said.

"If you go out there today, it's 6 per cent."

Crunching the numbers

Affordable housing is defined as a home that costs no more than 30 per cent of a low income.

While people on higher incomes can comfortably spend more than 30 per cent of their income on rent, Jenny said, people on a Centrelink income can be left with as little as $10 per day once rent is paid.

"If you are on around $300 a week and you're spending more than 30 per cent of that on rent, then there's not very much left over for utilities, other bills, food, getting the kids to school," she said.

Homelessness data from the 2017 census is yet to be released, but Jenny is expecting a big increase from previous census figures which showed 105,000 people Australia-wide were experiencing homelessness, including 23,000 Victorians.

"I think it's really important to understand that rough sleeping is just the tip of the iceberg of homelessness in our community — it's about 6 per cent.

"For every one of those there are many, many more who are living in really marginal and insecure circumstances."

Sorry, this video has expired 'It's a big problem getting enough sunscreen for homeless people,' says charity worker

The figures, she said, included people couch surfing with friends, sleeping in the backs of cars or staying in "dodgy temporary accommodations".

Jenny said there had been a rise in the number of people presenting to homelessness services.

"Nationally we saw 288,000 different people last year, which is a 22 per cent increase over five years and a more than 4 per cent increase each year."

Homelessness services have received little in the way of additional resources to cope with demand, meaning 98 people a day are turned away in Victoria alone.

"That's one in four people that we're not able to help."

Lack of social housing

Jenny said public housing was originally intended to provide homes for key workers such as chefs, police and nurses.

But successive federal governments have treated housing as a commodity rather than a necessity, she said.

"Every year we are supporting investors in housing to the tune of billions of dollars."

While government subsidies such as negative gearing may have been intended to boost supplies of low-cost rental housing, she said, they had failed to do so.

In 2015 non-government organisation Prosper Australia used water-use data to estimate that 82,724 properties lay vacant in Melbourne.

Meanwhile there has been little investment in public housing in recent decades.

"That's a big part of why we are in the mess we are in today," Jenny said.

"Many a bright mind has been exercised in the last decades about how to deliver social housing for the most disadvantaged in our community without spending government money, and there's not been a great deal of success.

"My view is there will not be.

"We can do clever things with partnerships, with institutional investors, we can involve the private sector, but in the end there will have to be some subsidy and support from government."

She pointed to research by Irish academic Eoin O'Sullivan who compared the approach to homelessness by Ireland, Denmark and Finland.

"His conclusion was that in many ways only Finland was successful," Jenny said.

"They effectively ended rough sleeping and they did it by investing in social housing; they did it by building houses for people."