The Cosmopolis actor bought the house in September 2011, reportedly worth $6.3 million.
Pattinson was alleged to have asked Stewart to move out of the property last month after she was revealed to have cheated on him with her Snow White and the Huntsman director Rupert Sanders.
Stewart has apparently been spending her time with her parents and best friend Scout Taylor-Compton since news of the fling broke, but she is not yet believed to have officially moved out of the house she shared with Pattinson.
A source told Us Weekly: "[Rob] said there are too many memories."
Another insider also claimed that Stewart and Pattinson "are talking" and that he holds no animosity towards her.
"Rob doesn't hate her and he's not mad... He just doesn't get why she did it. He loves her and thinks about her constantly," the insider alleged.
On Saturday (August 25), Pattison was reported to have gone on a date with 'Wide Awake' popstar Katy Perry, shortly after her split with John Mayer.
Meanwhile, Stewart is said to have turned to self-help books to help her cope after her cheating scandal.
Pattinson and Stewart, who met on the first Twilight movie, will be back on screen together when The Twilight Saga: Breaking Dawn - Part 2 comes out on November 12.
Watch the trailer for The Twilight Saga: Breaking Dawn - Part 2 below: