Apartment 4A

Apartment 4A is the primary permanent set for The Big Bang Theory, and is the where Sheldon Cooper lives. Leonard Hofstadter also lived in this apartment for 12 years with Sheldon until he moved in with his Penny. It is situated in an apartment complex at 2311 North Los Robles Avenue. By season 8 after Penny and Leonard's, she was seen living there most of the time though not officially moved in. When viewed from the photographs in "The Countdown Reflection" episode, it appears to be located at 215 South Madison Avenue. Due to the primary characters in the series, except Penny, being of the "nerd" social classification, the apartment has been dubbed as "Nerdvana" by Howard in season 1 episode 14 "The Nerdvana Annihilation".

Apartment 4A is located on the fourth floor of the building across the hall from Apartment 4B, where Penny lives and where Leonard lives now. Apartment 4A is known to be a corner apartment, being that it has facing outside on two sides. It may, in fact, be one of only two apartments on the floor, and may therefore have outside walls on all sides (other than the wall shared with the fourth floor hall and stairwell.

Apartment 4A is also a hidden (apt 4A = foray)- either a "great raid" or the voice of,.

For information on the actual view from their apartment see

Layout
The apartment has one, one , and two s. A hallway links the living room to the bedrooms. The kitchen is part of the main living area.

Immediately upon entering, the wall on the right houses Sheldon and Leonard's s and the. The wall ends in the kitchen part. This wall is rarely visible, being the wall that is the view into the apartment from which the episodes are filmed, and has only been shown on two occasions (one is in "The Euclid Alternative", S2E5 and the other is "The Colonization Application", S8E17). The first was a view of the apartment from the hallway and the second had Leonard sitting at his desk during Sheldon's video.

The wall immediately to the left after entering the apartment has a long that ends at a small closet, with the wall itself ending at a large window with a desk and. These bookshelves, behind the couch, serve to hold the boy's vast collection of books, some {{w|software}, as well as an ever changing selection of their various collectibles. can be seen from the window at the alcove, which has been used on several occasions:
 * "The Tangerine Factor" (S1E17), Penny throws her ex-boyfriend Mike's out of it.
 * "The Panty Piñata Polarization" (S2E07), Sheldon shows Penny that he hung her clothes from a outside.
 * "The Einstein Approximation" (S3E14), Sheldon throws a out the window, causing the sound of  tire screeching and car horns, implying that there is a fairly large road just down the window and that Sheldon just caused an.
 * "The Ornithophobia Diffusion" (S5E09), a lands on the  outside, which upsets Sheldon.
 * "The Countdown Reflection" (S5E24) Howard and Bernadette are married on a ceremony which is photographed by.

After the window, there is a corner and the hallway that leads to the bathroom, as well as Sheldon and Leonard's bedrooms. The kitchen area is a small area that has an island with rarely used s since they usually eat in the living room area. A window is located at the end of the visible wall of the kitchen area (which can be clearly seen in several kitchen area scenes, one typical instance is in "The Loobenfeld Decay" (S1E10), when Toby Loobenfeld talks with Sheldon in the kitchen area). Presumbly, this window is one of the two windows (the other being the large window described above) that Sheldon has stated "creates a cross breeze" when he describes his Spot.

Sheldon, at one point in time, had painted luminous arrows on the floor pointing to the various nearest s throughout the room. He shows them to Raj in "The Roommate Transmogrification" (S4E24), but gets rid of them before "The Friendship Contraction" (S5E15) when he explains that they were "wildly ".

Production-wise, the bathroom interior, Sheldon's bedroom, Leonard's bedroom and the connecting hallway are actually filmed on a different set than the rest of the apartment. The actual apartment set ends at a corner in the hallway immediately after the bathroom door which is for easier filming access and better view of the actors for the studio audience.

History
In "The Staircase Implementation", the story of how Leonard and Sheldon meet is revealed. Sheldon places an ad for a after his former roommate, Sebastian, is driven to the brink of madness from Sheldon's antics. Leonard encounters Sebastian on his way to the interview with Sheldon, and he tells Leonard to run far away. Leonard is accepted by Sheldon as his new roommate and inherits Sebastian's former room, only to discover that Sebastian wrote "DIE SHELDON DIE" in red (like in a ) on the wall.

At this time, the apartment also had significantly less in the living room. Sheldon's only placement was two s and s as the TV stand. Even at this point in time, Sheldon's lawn chair was placed in the exact spot that he claims later on the couch. Their first major addition in furniture to the apartment was the leather, in which Leonard buys for $100 from tenants on the first floor who were moving out; which is a great deal, since a new Moroni Havana Leather Sofa retails for around $1,500. Careful watchers may recognize the style of sofa; while the boys utilize the full 3 cushion sofa, defective  from the series "Monk" sports the smaller, two cushion model, of the line.

In "The Bozeman Reaction", the apartment got. Some of Sheldon and Leonard's game systems and various games were stolen. The were also called to the apartment in "The Zarnecki Incursion", when Sheldon's World of Warcraft account was hacked.

In "The Staircase Implementation", an "apartment flag" is mentioned as a small blue flag with a on it of a gold   on a  on it. Flipping it upside down signifies that the apartment is in distress. In "The Roommate Transmogrification", Raj was given a lapel pin version.

Bathroom
The bathroom is the first door down the hallway off the living room.

Check out The Bathroom

Sheldon's bedroom
Sheldon's bedroom is located immediately after the bathroom. Sheldon usually keeps his bedroom locked, and supposedly rarely allows anyone inside, however, given the number of episodes where Leonard, Penny, his mother, Wil Wheaton, Amy, and others have been there, this appears to be more wishful thinking on Sheldon's part than actual practice.

Check out Sheldon's bedroom.

Leonard's bedroom
Leonard's bedroom is the last room in the hallway. There is a ledge outside that runs by both bedroom windows. Sheldon uses this ledge during "The Bozeman Reaction" to access Leonard's room because he is too to go out of his bedroom because they were burglarized earlier in the episode.

Check out Leonard's bedroom.

Kitchen
The kitchen of the boys' apartment features an open floor plan that lets action flow easily between the living room and the kitchen space. The large type table provides a separate sitting area, allowing interactions in a setting more intimate than the clutter of the living room. The and Sheldon's {{w|tea} box provide "busy work" as the actors interact within the kitchen space, and it occasionally functions as an area allowing characters to briefly leave the room and re-enter quickly, allowing the characters remaining in the living room to talk or interact at their expense. For example the guys and Penny often laugh at Sheldon's s when he gets up to get a drink, and Penny famously touched Sheldon's food (taking and replacing an ) when he left his spot on the couch for a brief errand.

For more info, check out The Kitchen

Living Room
The living room serves as the for the majority of the "action" of the show. This is where everyone gathers, where gaming occurs, and where Leonard attempts to have intimate dinners with Leslie Winkle and Dr. Stephanie (constantly interrupted by Sheldon). The room serves not only to showcase Sheldon and Leonard's furnishings, collectibles, and artwork, but also serves as general storage space, given the number of partially assembled computer cases and other items around the area, including a vast collection of books.

Furnishings

 * [pilot] Round glass over large gear coffee table (where the gang usually eats and plays games)
 * [pilot] desks (for the laptops and iMac near the back window)
 * [pilot] Pubmaster dartboard by Sportcraft
 * [pilot] swing arm floor lamp in silver/nickel finish
 * [S01E02] marble-topped island vegetable bin with 2 drawers and towel bar, to the left of the front door (you can tell this is a veggie bin because of the dual hinges on the front of the drawers, the drawers don't pull out, but rather the front of the drawer pulls down/away, usually used for storing potatoes, onions, and other root veggies
 * [S01E02] 30 drawer library card file

Games

 * Gaming is a huge part of the boy's lives and constitutes the major aspect of their social lives. Gaming is SO big, in fact, that it now has it's very own section on the wiki. See Games

Sheldon's Desk



 * [pilot] silver/nickel z-bar lamp
 * [pilot] silver robot*

Science Stuff

 * The Meade 20218 NG-79SM 70mm Refractor Telescope gets replaced with a Celestron NexStar 102 SLT Computerized Telescope
 * Sheldon's reverse osmosis machine

Star Wars items

 * Han Solo & Luke Skywalker, Heroes of the Rebellion in Stormtrooper Disguise Sixth-Scale Figures, Luke appears on top of the bookshelves behind the couch in [S03E09]. Han appears in Leonard's bedroom in [S03E12]. These appeared in VERY limited edition.
 * In season 7 on the book case behind the sofa in the living room is a replica of the Yoda Lamp from The Empire Strikes Back. (First shelf down, far right side in the Scavenger Vortex episode. These are available from the manufacturer.)

Other film, television, pop culture

 * [S01E14] Dr. Who: a black dalek appears on the shelves behind the couch in The Nerdvana Annhilation


 * [S03E10] Lord of the Rings; Weta Gollum figurine— seen on Sheldon's desk in "The Gorilla Experiment"
 * [S05E05] Game of Thrones:"Longclaw" sword (Sheldon and Leonard buy it at the comic book store in "The Russian Rocket Reaction") — see this blog by the maker, Valyrian Steel, regarding their sword's appearance on the show

Miscellaneous

 * [pilot] Cutaway model of a DC-7 airplane. After the pilot episode, it gets swapped for a model of the space shuttle Atlantis.The plane shows up again in Leonard's room in S01E09, The Cooper-Hofsadter Polarization.
 * [pilot] Leonard's high school yearbook (read by Amy in "The Pulled Groin Extrapolation")
 * [pilot] Sheldon's and Leonard's whiteboards
 * stuffed animal "Timmy", the ThinkGeek.com monkey, can be seen sometimes on the end table next to Sheldon's spot, other times on top of the bookshelf behind the couch
 * [S02E11] Magic 8 ball by Mattel
 * Rubik's cube tissue box (seen in many episodes, but featured in "The Rhinitis Revelation" where Leonard holds it out to a sick Sheldon)
 * Christmas stuff
 * Batman/Bat Signal ornament
 * Superman logo ornament
 * Yoda stocking
 * R2D2 stocking
 * Darth Vader stocking

See Part 7: Shedding Light on Dark Matter of the book Unraveling the Mysteries of the Big Bang Theory by George Beahm (2011, BenBella Books, ISBN 9781936661312) for more fantasy, sci-fi, pop culture, and other items mentioned on the show in general.

Trivia

 * Sheldon plans to never stop living with Leonard.
 * After the death of Carol Ann Susi, who provided the voice of Debbie Wolowitz, the producers added a small photo of her on the side of the refrigerator facing the audience as a tribute to her.
 * Throughout the time Penny dated Leonard, she often slept in Leonard's Bedroom with him. Even after their marriage, they usually have to stay here because of Sheldon as he often gets lonely and he might have abandonment issues.