Flat jotter (3)
I believe the answer is:
pad
I believe this is a double definition.
'flat' is the first definition.
(person's home)
'jotter' is the second definition.
(I've seen this before)
(Other definitions for pad that I've seen before include "Stuff the animal's foot" , "Cushion" , "pack" , "Helicopter stand" , "Footprint - home of one's own (slang)" .)