Janice and Mark have catered all their main living spaces to their kids. But with the kids grown up, Jonathan and Drew revamp the house to make optimal use of the space.

Bel and John are building a radical underground house on 25 spectacular acres at Whittlesea, in Victoria's Plenty Valley

Brian and Sarah transform Michelle and Adrian's cramped backyard into a music-inspired oasis with a DJ den, arts wall, and hangout zones.