The 'Tree of Life' star had left the Los Feliz estate for a nearby rented apartment in Los Angeles when he split from wife Angelina Jolie last September, while she vacated the property with their children to live in a mansion in the Hidden Hills.
However, aerial photographs obtained by Grazia magazine show the 53-year-old actor's cars have been parked in the driveway in recent weeks, with neighbours confirming to the publication that he is "there most days".
And Brad is said to be remodelling the estate to be as "kid-friendly as possible", in order to boost his bid for joint equal custody of Maddox, 15, Pax, 13, Zahara, 12, Shiloh, 10, and eight-year-old twin Knox and Vivienne, with changes he's made so far including the installation of two giant trampolines, a playground, and a 50m skatepark for his oldest sons.
He is also planning to get out of the outbuilding within the grounds developed into a playhouse for the younger kids.
A source said: "Brad wants to prove to the courts that he's putting the children's welfare first.
"Obviously the family circumstances have changed dramatically, but he wants them to feel at home there.
"He's doing everything he can to try and fight or his kids."
Brad and Angelina recently reached an agreement to resolve their divorce and custody dispute in private.
They announced in a statement: "The parties and their counsel have signed agreements to preserve the privacy rights of their children and family by keeping all court documents confidential and engaging a private judge to make any necessary legal decisions and to facilitate the expeditious resolution of any remaining issues.
"The parents are committed to act as a united front to effectuate recovery and reunification."