The house looks like an ordinary country cottage with a hay roof, a wooden door, two small windows, grassy front garden, stone path, and a fence encompassing the house. The door's key hole is in the shape of an anchor.
The interior looks like what an average country cottage would look like. It has a big kitchen with enough equipment to make cookies, and a warm living room. In "Pet Sitter Pat," it is revealed that it also has a bedroom for Grandma SquarePants.
Role in series
SpongeBob visits his grandma's house to receive love from her and eat her homemade cookies.
Later in the episode, SpongeBob visits his Grandma's house with Patrick to show her that he has chosen to be a grownup from now on, no longer wanting kisses from his grandma. Patrick takes SpongeBob's place as the "baby" to which Grandma SquarePants feeds cookies and reads stories, until SpongeBob becomes jealous and reconsiders growing up.
While at his parents' house, SpongeBob finds another note from his eponymous cousin, this time saying he's going to pay SpongeBob's grandma a visit. SpongeBob arrives at Grandma SquarePants' house and she says BlackJack recently called her and left a message for SpongeBob, saying he has some "loose ends to tie up."
The house appears at the end of the episode when SpongeBob apologizes to his grandma for his abrasive side's actions towards her. He sees his grandma now has an abrasive side of her own, and he screams and runs off.
"Pet Sitter Pat"
SpongeBob visits his grandma's house for her birthday. He leaves Patrick in charge of Gary while he leaves, which causes him to make numerous phone calls to make sure Gary is in good hands.
SpongeBob smells the scent of his grandma's cookies and floats to her house to eat some, passing through many hazards on the way. When he arrives, he starts eating the cookies as his grandma kisses him.
Grandma SquarePants - Resident
SpongeBob SquarePants - Guest
Patrick Star - Guest
"The String"- The house was presumably destroyed when SpongeBob unraveled all of Bikini Bottom and the Milky Way with the string.
"Pet Sitter Pat" is the only instance of the house being shown at night.