A migrant family offering to shelter the homeless in their spare bedroom has been rebuffed by local charity groups.

Raj Zaveri moved from Mumbai to Canberra in 2015 to take up permanent residency.

He and his wife regularly travelled to Australia for work and wanted a better life for their young family.

Mr Zaveri wanted to repay the kindness he'd experienced since migrating by giving up their third bedroom.

"Sometimes people just need shelter for a week, and having that available immediately can make all the difference," he said.

The offer of a spare room was turned down by larger charities. ( ABC Canberra: Michael Black )

Door shut on charitable offer

Mr Zaveri hit a brick wall when he called St Vincent De Paul, OneLink and Barnados.

Each charity declined the offer, saying there were a lot of processes involved in managing such a donation.

"They don't mind if you want to donate blankets or give money," he said.

"Why is it so difficult for someone like me who's willing to offer help?"

It was not the first time he'd encountered hurdles with local charities.

He was turned down as a foster carer for having a cigarette habit, despite keeping the house smoke-free.

The service provider had strict health policies but were not concerned that Mr Zaveri kept alcohol in the house.

"I've never heard of anyone getting into a violent situation under the influence of a cigarette," he said.

The Zaveri family wants to repay the kindness they've experienced since moving to Australia. ( ABC Canberra: Michael Black )

Mr Zaveri had his own brush with homelessness which helped him empathise with people he'd seen on the street.

He was surprised there were so many people in Canberra without a roof over their head.

"Where I'm from, if you're out on the streets you need to get back on your feet on your own," he said.

"There is a criminal waste of resources in Australia."

He said it was disheartening to encounter so much red tape in the charity system and gave up.

The migrant family was shocked at the extent of the homeless problem in Canberra. ( ABC Canberra: Michael Black )

Startup offers a solution

Denise Hunter founded the charity Safe Haven to address the gap in services for domestic abuse victims.

Everyday people have registered their spare rooms as refuges for people in need.

"A lot charities are already full on with doing what they do best and haven't got time to manage accommodation," she said.

The inspiration came after Ms Hunter heard that nearly one third of calls to the national domestic abuse hotline went unanswered.

"Even if you'd answered them, where were you going to put them?" she said.

The Queensland-based service has expanded nationally and also caters for homeless people trying to find short-term accommodation.

Ms Hunter and her business partner Paul Ferry vet providers and manage the risks around guests in potentially violent situations.

"There's a lot of checks and balances and there's a lot at stake if you get it wrong," she said.

Ms Hunter believed there was a broader problem in the capital cities with unused space.

She estimated there were more than 600,000 homes sitting vacant in Sydney and Melbourne alone.

"I think we all whinge about the state of the nation, but nobody actually does anything.

"We've just got our attitudes and mindset on how things can work."