Bluestone Mansion - No idea what to put

[JoeyD473]

For the next D&D adventure I am running I am making a mansion. I would like it to have 3 floors, a basement is going to be just one big room (Probably) and first and second floor. I started doing it but I have no idea what rooms it should have and the sizes of the rooms.

A quick and dirty history of Bluestone Mansion

Bluestone Mansion is just outside of the town of Bluestone and has been abandoned for many years. It is believed to be haunted.

Though not known except to members of the Royal family and a few select supporters and advisers Bluestone Mansion was once a Royal retreat and safe zone incase of attack. A magic ammulet given to members of the Royal Family and those same select few can teleport them instantly to the basement of this mansion which is about 100 miles from the capital city.

I am doing the map in CC3 and is currently 400' wide by 240' not including two sections in the front of the mansion which is designed for guards. So what rooms should be on the first and second floor of this mansion, and about what size should they be? I can also make the mansion smaller if need be (I could make it bigger but I would prefer not)