Squidward's house's mouth is the door, but originally, its mouth was closed and a door rested underneath it. The house's exterior styling is reminiscent of a "Moai," giant statues found on Easter Island also referred to as the Easter Island Heads. According to page 36 of the 2004 book SpongeBob Exposed! The Insider's Guide to SpongeBob SquarePants, Squidward's house was built out of volcanic rock.
The ground floor consists of three adjoining rooms; the one at the front being the living room. The living room consists of a bookcase with some of Squidward's jazz records, a couch, a coffee table, and TV. Behind the living room is the kitchen with a fridge, an island counter, and four cabinets. This is where Squidward cooks. The dining room is off to the side and consists of a round table with chairs and a clamshell chandelier. There is a room off to the side with a spiral staircase leading to the second floor. There is also an elevator. Upstairs is a bedroom on the left ear.
In the bedroom is a canopy bed, a nightstand, and a closet with alarm clocks, as seen in "Employee of the Month." Off of the bedroom is a bathroom with a toilet, sink with medicine cabinet, and a Jacuzzi tub/shower. There's also a gallery where Squidward paints his self-portraits and plays the clarinet. Other upstairs rooms include a library and backroom. The architectural style is Polynesian.
In some episodes, it is shown that he has a backyard and at times, raises a garden there.
Kitchen: This room is at the back. This is where Squidward cooks and prepares his food.
Dining room: Next to the kitchen. This is where Squidward eats his meals and is where he keeps his shellphone.
Living room: Squidward watches TV and enjoys Sundays here, as seen in the episode "Good Neighbors."
"Skill Crane" - Squidward gives up the deed to his house while he was trying to win a prize.
"Good Neighbors" - Squidward busts his head through the door screaming that SpongeBob and Patrick are the worst neighbors ever when SpongeBob said if he was going to say something. It then comes alive and destroys Bikini Bottom.
"Rule of Dumb" - Patrick moves his house to make a Ferris wheel, destroying the inside and dropping the house into the ground.
"House Fancy" - When he was in a hurry, he made SpongeBob vacuum, the vacuum cleaner exploded and the house remodeled. Also, after Patrick used Squidward's bathroom, the toilet crawled out moaning and then died.
"Big Sister Sam" - Patrick's sister, Sam Star, throws Squidward's house, removes parts and then chews up the parts into small bullet-like rock, blows them out, and destroys his house completely.
"A Friendly Game" - It was destroyed by SpongeBob and Patrick when they were looking for their golf balls and making shots where they left it.
"Bubble Buddy Returns" - Bubble Buddy's son goes into the house destroying many internal possessions, including his kitchen and a collection of glass menagerie he owned with one of the four containing a version of himself as a mermaid.
"Little Yellow Book" - Squidward's house gets repossessed after reading SpongeBob's diary.
"Sold!" - SpongeBob and Patrick destroy his house by flipping it before the house collapses at the end.
"Man Ray Returns"' - SpongeBob and Patrick battle Man Ray inside the house and completely trashed the place. They even tried to put everything back together with their saliva, but when Squidward returns, the house completely crumbles to the ground.
"Bunny Hunt" - Squidward hits his house with a hammer to get rid of the sea bunnies, causing it to collapse.
"Shell Games" - Tony uses Squidward's house as a shell, creating holes in it for his arms and legs.
"Pat Hearts Squid" - It tips over and brakes and later gets destroyed in the end.
Squidward's house appears to have a mind of its own, usually to give a comedic effect.
In a Nick Magazine comic strip titled "House of Squidward," there is a switch buried in the backyard that makes Squidward's house come to life. He grows feet and arms. He is brought to rest when SpongeBob, Patrick, and Squidward cleverly disguise SpongeBob's house as a woman. Using a microphone and a speaker controlled by SpongeBob, they can trick the house into sitting back down behind the walkway and then flip the switch to keep Squidward's house from moving.