The $20 million-plus new home of drinks distributor turned property developer Harry Stamoulis in Toorak, Melbourne is about to be left in the shade by another mega property under construction next door. Lawyer and property developer Daniel Besen, son of billionaire retail magnate Marc Besen is building a palatial home nearby expected to cost tens of millions of dollars and make it Melbourne’s most expensive property.

Mr Besen, 46, a former director of the Melbourne International Arts Festival and the Heide Art Gallery, is constructing his new home that is reported to include a high-security underground gallery to house his priceless art collection, a climate-controlled basement garage, as well as at least two above-ground levels. It is reported the project will exceed in cost and complexity Harry Stamoulis’ pile.

Mr Stamoulis bought his half-hectare property for a record-setting $24 million in January 2010. The Federation-style house at 39 St Georges Road that had been on the site and in the Baillieu family for 70 years was demolished. The property Mr Stamoulis’ built in its place was the largest single residential project in recent Victorian history, though that record is set to beaten by Mr Besen’s residence. The site of the Besen home is over 2300 square metres, more than ten times the size of an average new house in Melbourne. The site alone is worth almost $10 million.

One Toorak resident told The Age that they were ”horrified” at the size of the construction jobs in the area. “It is not appropriate for nearby residents to have to endure the associated disruption, building noise, obstructed private driveways and road closures for a period of 2½ years in order to satisfy the materialistic and ego-driven consumerist need of a few,” the neighbour said. With most of the subterranean work complete including a lift shaft, a complex, curved mansion, now appears to be under construction. It is expected to take another two years to finish.

A planning permit from Stonnington City Council is not required for single dwellings in Residential 1 Zone where the site is larger than 500 square metres. When complete, the Besen home will be a counterpart to that of mining magnate Socrates Vasiliades, which took more than six years to build. Mr Vasiliades famously lived in the 22-room mansion at 3 Towers Road in Toorak for just six days and then put it on the market in April for $30 million. If sold at this price it would set a record for Melbourne.