A SkyCity executive could set this year's national house price record with a sale his agent predicts could be around $20 million.

Rob and Kim Hamilton's place is on Aldred Rd, Remuera, and is an American colonial-style home which they bought 18 years ago for just over $2.5m.

Rob Hamilton is SkyCity's chief financial officer.

The house is now being advertised for sale carrying a CV of $15.1m.

However, agent Michael Boulgaris says he expects to get well over the CV for the extensively renovated place which stands on around an acre of grounds.

The Hamiltons had spent a considerable amount of money on the grounds and the house and had changed it to such an extent that really only the house facade was the same, Boulgaris said. A new swimming pool and new tennis court were developed, he said.

Hamilton said the home was bought for his family and he was reluctant to talk about it other than to say now that the children were older, he and his wife were looking to move to a smaller home.

However, they had not yet bought and were open to offers.

"My observation is that properties in this market are still selling comfortably above CV. You might look at recent sales in the area," Hamilton said.

In July, the Herald reported on the transfer of a $13.9m "stunning hidden getaway" near Arrowtown which had then set the record for 2019's most expensive sale.

The Hamilton's house has five bedrooms, a rumpus room, family bathrooms and ample storage and wardrobe space, advertising says.

"The ground level is designated to expansive living, with multiple French doors opening to the sizeable northern and western loggias with views over the swimming pools, tennis court and valley landscape," Boulgaris says.

Two freehold titles were combined to give a 3915sq m area, or more than a third of a hectare of relatively flat usable land, he said.

Nick Goodall of CoreLogic said CVs and sale prices differed wildly when it came to the country's most expensive homes. Often, wealthy people paid well over CV to get what they wanted.

"Exceptional properties attract certain types of people who will pay whatever they want because it's all about securing that property and they don't care what the CV is," Goodall said.

OneRoof editor Owen Vaughan said: "In the past 12 months, the top end of the market in Auckland has struggled to achieve the record sale prices that seemed to notch up on a weekly basis during the boom.

"That's partly due to the foreign buyer ban and homeowners deciding to stay on the sidelines, but the recent lowering of interest rates and a lack of stock on the market is starting to lift buyer activity, with auctions again helping to drive higher than expected sale prices."

Several properties have been sold during 2019 for an excess of $10m but none come close to last year's residential high of $25.5m, let alone the all-time record of $39m set in 2013.

You'll be surprised by how many dollars it adds to the value of a home.

Financier Martyn Reesby bought Te Rere Cove, valued last year at $24m, for much less than that during the winter. He said in July he had bought the house, all wine-making facilities and part of the vineyard on an 8.8ha title. He had not bought the neighbouring 5ha, planted in pinot gris. He is thought to have paid around $12m for one of the two titles.

Check out the listing for 12 Aldred Rd, Remuera, Auckland on OneRoof.co.nz