Adam joined the McGrath agency network, initially for six years. Following subsequent stints with Frasers Property Australia, Brookfield Multiplex and Crown Group, he recently rejoined McGrath, this time in charge of its 44-person project marketing division, which sells off-the-plan developments on the east coast.

In Sydney, in his own home in Castlecrag, Adam has taken interior design inspiration from the hundreds of penthouses and apartments he has sold throughout his career.

Adam and his finance executive wife Delia have totally renovated the 1950s house they bought for more than $1.6 million in 2011, estimating they have ploughed up to $500,000 into the three-bedroom property in an exclusive street called The Redoubt, Castlecrag. The pair believe Castlecrag, a leafy suburb about 15 minutes north of the Sydney Harbour Bridge, is “undervalued”.

Indeed a 1960s house in Castlecrag on 777sq m recently sold for $2.325m, a steal compared to many lower north shore areas such as Greenwich, Mosman and Longueville. At least half of the Sparkes’ outlay was spent renovating the swimming pool into a stunning entertaining area with new tiling, landscaping and palisade fencing, which backs onto the rainforest where the family have spotted the odd rock wallaby.

More cash has been spent renovating bathrooms, adding plantation shutters and expanding a wine cellar, which is kept perfectly cool because of the house’s sandstone walls.

“I think we will be here until we are old and grey. We might downsize to an apartment in about 15 years,” Adam says. “The agent in me is tempted to upgrade again, but where would we get such a quiet street?”

In fact, the neighbours are so friendly Adam and Delia and their 10-year-old son Tristan recently holidayed with them in Vietnam’s Hanoi and Cambodia’s Angkor Wat.

One neighbour, a handyman, has lifted the Sparkes’s house’s existing cellar from a capacity of 100 to 750 wine bottles.

And they are not afraid to drink the wine, spending the summers entertaining the neighbours around their lavish swimming pool and landscaped gardens.

“It’s a very social, really nice street,” says Adam. “There are only eight homes, they are similar families, it is quiet, peaceful and close to the shops and there’s excellent restaurants such as the Malaysian inspired Yang & Co in the Castlecrag strip shopping centre.”

There are three family members, but the fourth, a one-year-old puppy called Fynn, is the most popular member of the Sparkes family according to Adam and Delia. Acquired from Canberra-based breeders, Fynn is a Havanese, a breed of Bichon bred for the Cuban aristocracy in the 1800s.

The renovations have been complex but the family has coped by having the major works done, such as new limestoned American oak engineered floors, installed while holidaying abroad.

The downstairs walls are adorned with artworks including an unusual photo of actor John Malkovich posing as Salvador Dali by American photographer Sandro Miller, while a large colourful oil painting by Melbourne-based artist Matthew Johnson covers the sumptuous living room upstairs. Colourful ceramic drum stools, rugs and cushions adorn the living rooms and outdoors with many of the furnishings sourced from Coco Republic and Homeware Gallery in Sydney’s Botany Road.

The light-filled and heavily mirrored house is unrecognisable from its previous incantation, where the former owners had painted the walls in a range of different colours, including dark ­purples.

And with the master bedroom suite cantilevered out over the backyard and looking across Sailors Bay Creek, Adam says the house is a landmark for the area.