Sadiq Khan has approved the restoration of the historic Grade II listed Hanworth Park House for community use.
The land around the building on Forest Road will see five tower blocks erected with 40% of the development to be designated for council rent.
The council says the project is a significant step forward, providing crucial public benefits, including opening up overgrown woodland for the public.
The private residential development element will facilitate the restoration of Hanworth Park House which will remain in private ownership.