BUILDING will start this month in Melbourne's blue-chip suburb of Toorak on one of the state's largest and most expensive new homes.

The manor of soft drinks distributor turned property developer Harry Stamoulis at 39 St Georges Road is expected to rival neighbouring Toorak mansions Stonnington, Miegunyah and Cranlana in size and take 2½ years to complete.

''The project could be considered one of the largest commissioned single residential projects in recent Victorian history,'' said Wayne Krongold from builders Krongold Constructions.

While neither the project's architects Bruce Henderson or Mr Krongold would comment on the Toorak home's cost, industry sources suggest it will take more than $20 million to complete.

Mr Stamoulis bought the half-hectare property in one of the suburb's best-known boulevards for a record-setting $24 million in January 2010 near the height of the market. The Federation-style house at 39 St Georges Road that had been in the Baillieu family for 70 years was subsequently demolished.