Plans have been submitted to turn Hull's House of Fraser store into a "dynamic mix of retail, restaurant, residential and office space".
The freeholders of the store - Redefine Paragon Square Hull Limited - claim they have been "overwhelmed" by demand for luxury serviced apartments in the store, which they are now branding 1, Paragon Square.
The store was saved from closure in the run up to Christmas after a deal was reached between the landlord, Sports Direct boss Mike Ashley and Hull Council.
A spokeswoman said House of Fraser would remain on the basement and ground floors while the upper levels would be comprehensively redeveloped for apartments and office space.
Caffe Nero which has a shop on the first floor would also be staying.
The owners are talking to various leisure and retail users and restaurants.
She said: "There's going to be a new facade, the interior will be completely redeveloped to make office space and apartments on the upper levels."
Their sales and marketing campaign for the apartments will be up and running in the next few weeks.