A granny flat used to be a term for the small backyard home built for ageing family members, but amid a housing affordability crisis, younger generations are changing its meaning as they move in instead.

Anthony Di Marino, 25, and his girlfriend Maddy Calderon, 26, moved into a granny flat at the back of Di Marino’s parents’ house at Normanhurst in Sydney’s north so they can save up for a house.