Glen Hansard was on The Late Late Show last night and he told Ryan Tubridy about how the Apollo House movement came to be.
He explained how for him, personally, he became more aware of Ireland's homelessness crisis.
He said: "Sitting around with friends talking about this stuff or just walking around Dublin noticing more and more people on the streets and having to pass people by and having to make that awful decision not to give.
"I was doing the Christmas gigs, and busking, but realised it wasn't enough."
Hansard then explained where the spirit of the Apollo House movement originated.
He said: "There's an Irish word 'meitheal' which doesn't really have a direct translation but it's more like gathering.
"If you have John-joe's shed fallen down the people of the village get together and they help build John-Joe's shed back up, which is a kind of transaction there, but it's never really called on. It's just communal energy to try and fix something that doesn't seem to be getting fixed."
You can hear him explain it to Ryan in the video below.
Staying with Ireland's housing crisis, Ryan then had a panel talking about the rental crisis in the country.
He had Room To Improve host Dermot Bannon, Karl Deeter of Irish Mortgage Brokers, and Linda Daly, editor of the Sunday Times property supplement, Move, on the panel.
Mr Deeter explained the three classic ways to become wealthy in Ireland, and why younger generations are giving up hope that they will ever own a home.
He said: "They're doing other things with their money, they're valuing experiences more."