Sandy's Treedome is a huge dome where Sandy lives at. It is a huge, polyethylene manufactured dome. It has an oak tree in the middle and lots of other plants around for oxygen so Sandy can live under water. In order to reach the dome, it crosses a kind of air lock; it is equipped with a loudspeaker to welcome visitors already early as possible.
 About the Treedome
Sandy's treedome is the one place where she can take her oxygen suit off, as the tree inside produces oxygen, and is helmetically sealed off. Whenever SpongeBob and/or Patrick goes into Sandy's Treedome, they must wear a water helmet, and whenever Sandy wants to walk outside of the Treedome (in water), she then needs to wear her oxygen suit. The oak tree in the middle provides acorns and oxygen (and in "A Flea in Her Dome", apples) and it has a door in the bottom of the stump. Inside of the trunk, up a staircase (or elevator), there is an average network of rooms which is shown in some episodes. Sandy is located at 126 Conch Street, Bikini Bottom, Pacific Ocean.
 Inside the Tree
Inside the Treedome's oak tree there is:
- A bedroom with a wooden bed and nightstands (and possibly a closet and drawers) made out of sticks from the tree. Inside is kept a table made of a piece of flat wood that grew from the tree, and on this table is a telephone made from acorns, sticks
, and a leaf.
- There is a large living room with wooden sofas, rugs, and a TV made from an enormous acorn. There is also a coffee table made from a tree stump. The kitchen and dining room may be connected to this room.
- Since Sandy is a scientist, she may have a lab where she works on inventions.
- The walls are made out of leaves which are on the tree.
- The floor is made of wooden floorings.
- There is a shower where Sandy washes herself when coming home. It has a hook for her pelt.
On Sandy's lawn, there is a wooden, fold-up picnic table covered with a plaid tablecloth. There is a birdbath, and a wheel for sandy to run on.
- Tea at the Treedome
- Sandy's Rocket
- MuscleBob BuffPants
- Karate Choppers
- Sleepy Time
- Valentine's Day
- Bubble Buddy
- Pre-Hibernation Week
- Christmas Who?
- Survival of the Idiots
- Squirrel Jokes
- The Smoking Peanut
- Pranks a Lot
- Funny Pants
- Chimps Ahoy
- Patrick SmartPants
- SquidBob TentaclePants
- Squidtastic Voyage
- Best Day Ever
- Spy Buddies
- A Flea in Her Dome
- To Save a Squirrel
- What Ever Happened to SpongeBob?
- Patty Caper
- The Krabby Kronicle
- Truth or Square
- Someone's in the Kitchen with Sandy
- Yours, Mine and Mine
- Whelk Attack
- A SquarePants Family Vacation
There are three episodes where someone from the outside in the water goes into her treedome without a water helmet. First was Tea at the Treedome. Second was Squirrel Jokes. Third was Yours, Mine and Mine.
In every treedome episode except for the snow ones, there is lush green grass, many wonderful flowers, the tree has more leaves that are lush green, and it is at an average temperature. There are other features and items such as a:
- Boxing Ring - as seen in MuscleBob BuffPants
- Hamster Wheel
- Oak tree in the middle
- Weight lifting equipment and the "Arm Cruncher"
- Glass Dome
- Some flowers
- Escape pod to Texas
- Trap floor - as seen in A Flea in Her Dome
- A Park Bench and Table
- A Bathroom
- Push-button telephone that cuckoos.
- Bird bath - as seen in Tea at the Treedome
- Nut Phone - as seen in Wormy
- Acorn-shaped television-as seen in Tentacle Vision
- Table made from a tree stump
- Table made from an unusual tree growth- as seen in Karate Choppers
Features in Winter Although it is normal in spring, it is much different in winter. There is winter snow which covers the whole ground, and there are no leaves on the tree, just snow. It is also at a very cold temperature, and basically, everything is mostly covered in snow. (as shown in the episodes Bubble Buddy and Survival of the Idiots)
 Destruction/Fill Up
- Pranks a Lot - After getting scared into thinking they were ghosts by SpongeBob and Patrick, she activated an acorn-shaped rocket and used it to blast out of the treedome and into Texas. She created a hole in the dome which let water in.
- Squirrel Jokes - After dehydrating SpongeBob, she turned on a hose and stuck it into SpongeBob, causing him to swell up and fill up the dome.
- In the video games "Revenge of the Flying Dutchman" and "Battle for Bikini Bottom", Sandy has many leaks in her dome.
- A Flea in Her Dome - Sandy brought a flea into the treedome and it created more fleas, creating a flea flood. To take them out, she flooded the treedome with water. This sucked up all the water and its inhabitants into the dome.
- Bubble Troubles - The air line was ruined by the hot sauce bubbles from SpongeBob and Patrick which caused the water to fill up the treedome.
Sandy uses her treedome to live and hibernate.
 First Ones In
- SpongeBob first went into the treedome on the episode, Tea at the Treedome (without a helmet).
- Patrick first went into the treedome on the episode, Tea at the Treedome (without a helmet).
- Squidward first went into the treedome on Squidtastic Voyage.
- Some of the fish first went in on The Krabby Kronicle, and later came in on the episode, Overbooked.
- Mr. Krabs first went in on the episode, Overbooked.
- Plankton, without a helmet, went in next on Someone's in the Kitchen with Sandy. However, a 2006 game called "Scene It? Nick" said who has not been to the treedome on a "misfits" question. The answer was Plankton, but that is because they did not know this episode would be in the future in 2009.
- Sandy does not really "own" her house, but "rents" it out. It is owned by Tree Dome Enterprises, as revealed in Chimps Ahoy.
- In The Krabby Kronicle, it is revealed to be a private treedome.
- Sandy's Treedome is able to suck up the entire Pacific Ocean.
- It is unknown how the Treedome got to the bottom of the ocean. However, Tea at the Treedome suggests that Sandy dragged it down.