The house to be built by Mittal, chairman of ArcelorMittal, the world's leading steel company, is in a conservation area nestled in a pretty corner of Surrey, southeast England.
The estate, Alderbrook Park, will grow enough wood from continually replanted trees to feed giant biomass boilers that will provide heating and hot water.
According to plans awaiting the approval of local authorities, the Mittal manor will have at least 10 bedrooms, outdoor and indoor swimming pools, a fitness centre, an underground art gallery, tennis courts, sculpture gardens and that very English feature, a croquet lawn.
A spokesman for ArcelorMittal told Hindustan Times, "The family never comments on these things."
A detailed graphic illustration of the mansion shows two gigantic four-sided pyramidal roofs sitting on the house's flat roof.
They will have solar panels that will vent warm air through the house when it gets cold, while providing heating and hot water. And the flat roof will store rainwater.