Forget the infinity pools and gourmet kitchens, the granny flat is the latest hot-shot property feature.
The rapid growth in ageing population and shortage of aged-care accommodation was the impetus for regulation changes in 2009 to streamline granny flat construction with approval now possible within 10 days.
But the demand is also driven by other forces that mean gran is now battling to compete with hard-to-shift adult children or tenants who are helping to pay off the owner's mortgage.
Brad Smith from Bulli said his granny flat would eventually meet all three needs.
"My daughter moved into the flat we had built with her partner and now she's moving out and allowing my son in," he said.
"After he leaves it is an option for our ageing parents and after that we intend to look at it for perhaps a uni student as a source of extra income."
Wollongong City Council reported receiving 86 applications for dual occupancy in the past year but it could not differentiate on how many of these were for granny flats.
Ross Meiklejohn from Unibuild at Albion Park Rail said his company, which specialises in sheds, also builds granny flats but he said most were used to generate rental income, often to help pay off the mortgage.
He said only one of four this year had been for an ageing parent, and even that had a twist.
The occupant, Faye Lindt, a retired hospital cook, said she moved into the granny flat at the back of the family home at Warrawong six months ago to help her son and his large family who now occupy the home.
"It cost $82,000 and is plenty big enough for me . . . I've been here nearly six months and find the arrangement works well and I'm happy to help my son."
Numerous real estate agents spoken to agreed granny flats had become popular drawcards in getting people through the door.
"I've sold two houses with granny flats in the past month - one didn't even hit the market because it sold to the first client who walked through the door," Sally Absalom from OneAgency said. "It was in Balmoral St at Balgownie and the buyers said they wanted the granny flat for guest accommodation."
Bevans agent Phil Murray, however, said the negative could be the the privacy issue involved in living at such close quarters.
"Whether it's a family or rental property, some people find it difficult to share their living space on one block of land," he said.
Changes to state planning policy in 2009 simplified the process of building a granny flat with a uniform maximum of 60 square metres compared to the old system where individual councils ruled on maximum size.
The changes were driven by widespread concern over the prospect of housing a rapidly increasing ageing population (see fact box).
Illawarra architect Mark Northwood said the changes clarified much of the confusion surrounding granny flat construction but also tightened standards to improve issues like fire safety and termite control.
He said while he supported granny flats as a way to maintain independence for ageing parents, his client base was looking looking outside the box for different uses to suit their lifestyle.
"Some people like to have them there for visiting family and friends, but most of my clients seem to use them for older teenagers or young adult children as a transition before they move out."