A Christchurch mansion owner is selling the land of his demolished home after losing a court battle with his insurance company.

The land used to be the site of Riverlaw, a three-storey 1880s homestead which was demolished in 2012 due to earthquake damage. The property is opposite the Heathcote River at the base of Murray Aynsley Hill in Hillsborough.

The 7,725sq m site has been put up for sale after owner Paul Myall lost a High Court battle with Tower in March for under-insuring the multi-million dollar building, Fairfax Media reported.

Myall bought Riverlaw in 2003 and had the 799sq m house incorrectly insured as 650sq m.

The High Court ruled that Tower should only pay for 80% of the full replacement value to reflect 80% of the insured floor space – or almost $3 million - Fairfax said.

Real estate agent Ian Rule, who is handling the sale of the property, said they were talking to interested parties.