Plans to demolish ... Craig-y-Mor.

A powerful Chinese couple's plan to demolish one of Sydney's most expensive houses will be decided by Woollahra Council tonight.

Zeng Wei, also known as Arthur, and his wife, Jiang Mei, want to knock down Craig-y-Mor in Wolseley Road, Point Piper, which they bought two years ago for $32.4 million. They plan to replace it with a modern five-level, eight-bedroom home, costing $5 million.

This will be the pair's third attempt to get the plans approved, after earlier incarnations were rejected because the replacement house was declared too big. They originally planned to have two swimming pools and a larger house, but scaled this back to one pool.

Craig-y-Mor's planned replacement, designed by architect Stephen Gergely.

The house still exceeds planning rules in many aspects, but the architect for the couple, Stephen Gergely, argues that the design sits comfortably among the mega-mansions of Wolseley Road, one of the 10th most expensive addresses in the world. The couple, aged 42 and 38, have two young sons. They live in China but are believed to be preparing to move to Sydney.

One neighbour, who asked not to be named, said ''they have paid a staggering amount of money to knock over a very nice house''.

The house was built in 1908, and redesigned by the architect Leslie Wilkinson in the 1960s, but it is not heritage listed. It is known for its high ceilings, bay windows, arches and a colonaded central courtyard. It has been lived in by the consul general of Japan, the stockbroker Rene Rivkin and the stevedoring company owner Chris Corrigan.

The construction of the new house will involve digging into the sandstone bedrock to allow two levels to be built underground, including a massive garage. The excavation will remove as much as 2600 cubic metres of earth, described by the council as an ''excessive amount of excavation for the site''.

At a council meeting on September 27, the Greens councillor Nicola Grieve described it as ''long wall mining in Point Piper'' and suggested that the owners may need to seek a mining licence.

Ms Jiang is a director of a $HK32 billion ($4.2 billion) Hong Kong-listed development company that builds shopping malls underneath main highways in bustling wholesale business centres in large and medium cities across China, often converting civil defence shelters into shopping centres.

A spokesman for the family, Gavin Slaughter, said the family were unable to be interviewed because they were in China.

Asked what Mr Zeng did for a living, he said: ''I don't ask them questions of what they do in China … what they do over there is their business.''

If the council rejects the plans tonight, the couple can appeal to the Land and Environment Court.