The main house, Headley Park, was built between 1884 and 1891 and was in family ownership until 1947 when it became a preparatory school. Latterly Headley Park has housed a country house club and social centre.
Headley Park Hotel has now been closed since 2015.
The new hotel will have 73 bedrooms including 14 lakeside lodges and a family cottage.
A new barn is planned in the hotel grounds which will house a spa, wellness centre and restaurant.
Headley Park is surrounded by woodland which is designated as a Site of Importance to Nature Conservation (SINC). It is located in Picketts Hill, East Hampshire.