The waiting list for public housing in Canberra has blown out over the past four years, a new report suggests.

According to the Productivity Commission's Report on Government Services, there were 2,300 people on the waiting list for public housing last year, an increase of more than 900 people since 2010.

The ACT has the second highest rate of homelessness in the country, with about 50 out of every 10,000 people in Canberra homeless.

But ACT Housing director David Matthews said the waiting list was starting to improve as rental prices in Canberra dropped.

"The waiting list does fluctuate over time and we would expect it to level off or to decline over the coming period," he said.

"What we've seen in Canberra over the last year is quite a significant decrease in average rental rates for people in units and in houses.

"As the private rental market is becoming more affordable, there will be less people seeking assistance for public housing."

But Mr Matthews said the waiting list numbers could be deceptive.

"What a waiting list represents is all the people seeking assistance," he said.

"If you're in a homelessness service you'll be regarded as being homeless under the data, but you'll also be receiving support.

"We not only record the people we're providing support to, but those that are awaiting assistance and those we were unable to assist.

"In Canberra we probably have the best picture of what demand is; it doesn't necessarily mean that our patterns of demand are radically different from other parts of Australia."

Travis Gilbert from ACT Shelter said it appeared a recent drop in rental prices and new investment in housing was making a difference.

"It's always a concern when [public housing] waiting lists increase but that appears to have stabilised," he said.

"We did see some significant investment in new public and community housing properties driven largely by the nation building and the economic stimulus plan."

Older public housing stock facing maintenance problems

The report also showed that the ACT had the lowest number of public housing properties with fewer than two major structural problems.

Just over 80 per cent of public housing tenants said the housing provided to them met their needs, the lowest rating in the country.

"The age of public housing in Canberra is the highest in the country, so we've got the oldest stock," Mr Matthews said.

"It provides a number of challenges like it's more costly to maintain, but also it's less environmentally friendly."

The ACT Government announced last year that it planned to renew public housing along Canberra's main thoroughfare Northbourne Avenue.

The report also showed there were almost 300 fewer public housing dwellings in Canberra now than 10 years ago.

The number of public housing dwellings dropped from 11,139 in 2004 to 10,848 in 2014.