Karen McCartney wasn’t always a connoisseur of mid to late 20th-century Australian houses. In fact, there was a time when she was, by her own admission. “frankly ignorant” in the matter. But that was some 25 years ago and the Irish lass had recently married an Australian lad and just moved to Sydney “for what was meant to be two years”.

Not long after they arrived, the pair stumbled across an intriguing flat-roofed, brown-brick sixties abode perched on a bushland incline overlooking Middle Harbour just north of Sydney. The mid-century bug bit. (The water-view bug, too.)