Fairfax family puts Sydney Harbour mansion on the block John B. Fairfax's Point Piper mansion on Sydney Harbour. THE Sydney Harbour waterfront mansion owned by the Fairfax family for 122 years has been put on the market in what could be the most expensive ever residential listing in Australian history. Selling agent Ken Jacobs said it was impossible to give an expected price for the heritage-listed mansion, known as Elaine, which covers six titles and is three times the size of nearby Altona, which fetched $53m earlier this year. The Fairfax family is selling the 6900 square metre property, fronting 550 New South Head Road, Point Piper, saying it is redundant. This is the most significant listing ever to hit the market in Australia. We are in the process of embarking on an international marketing campaign and that will take several months to get our due diligence together," said Mr Jacobs, of Christies International Real Estate. "There has been no comparable sale in Australia," he said. Altona is one-third the size at 2400sqm ... this estate, Elaine, is about 6900sqm. It is a completely different feel, it is a true estate. The house holds a special place in the history of the family, and Mr (John B.) Fairfax thinks it's now time for a new family to enjoy the home," a spokesman for the Fairfax family said today.