"They are going through extreme renovations and it's almost unlivable there now," a source tells PEOPLE about Affleck and Garner's decision to rent actress Brooke Shields' nearby home. "[It] is convenient."
Adds the source: "[Affleck] is with the family for the summer in Atlanta and he will move together with the family – when they are back – into the new place temporarily."
Currently, Garner, 43, along with her children – Violet, 9, Seraphina, 6, and Samuel, 3 – are staying in Atlanta while she films her new movie, Miracles from Heaven.
Affleck, 42 – who resides in a guest house at Garner's rented property in Atlanta – flew to Georgia for the second time this month on Monday and was spotted carrying a furry friend.
"It's their new puppy," says another insider of the addition. "It's a family dog. It's another sign they are working together to raise kids and be in a kind relationship."
The stars have also both been seen wearing their wedding rings, a gesture that is intended to help the kids through their parents' divorce, adds another source.
Reporting by LIZ MCNIEL