People who help the homeless in Calgary are welcoming Ottawa's ambitious $40-billion housing strategy, but some are concerned the money won't flow fast enough.

The Liberal government announced the federal 10-year strategy on Wednesday, promising it will result in the construction of 100,000 housing units and refurbishments to many more.

Ottawa is also planning to roll out a national housing benefit that will give qualifying families an average of $2,500 per year starting in 2020.

The government says the benefit will help support 300,000 households by 2028.

Nick Falvo, director of research at the Calgary Homeless Foundation, says it's a bold commitment from Ottawa backed by significant dollar amounts.

"But the bad news is the lengthy timeline. So, it will take some time for us to see differences on the ground," he said.

The federal government says its goal is to reduce homelessness by 50 per cent over a decade.

Abe Brown, executive director of Inn From the Cold — which has opened its emergency overflow shelter for families 25 times since April — also welcomes the new national strategy.

"You know, we're in a bit of a crisis right now, so it can't come fast enough," he said.

"Our hope is that by giving some of the money directly to the families themselves, that will incentivize builders to hopefully build larger unit sizes, because right now that's been a major challenge. And it's actually keeping families with two children or more essentially trapped in homelessness."

Most of the funding for the federal plan was already announced in the 2017 budget and will therefore not have any impact on the federal government's fiscal plan.