Sydney's Martin Place isn't where you'd expect to see a third-world slum home.

But that's where one has been temporarily set up to raise awareness about people living in inadequate housing around the world as the federal government puts the brakes on foreign aid.

The 12-square-metre hut, set up by the Christian non-profit organisation Habitat for Humanity, is made from scrap metal and has only one room and an elevated platform made out of spare timber for a bed.

Sophie Cooke has worked in slums in Bangladesh as international programs coordinator for Habitat for Humanity, which builds affordable housing in partnership with people in need.

She's hoping Australians will get behind their cause.