Architectural configuration was the name for the circuits (PROSE: Cat's Cradle: Time's Crucible, AUDIO: The Fate of Krelos) that controlled a TARDIS's ability to move rooms around and delete rooms as if it were a computer. If a TARDIS was sluggish, a room could be jettisoned (or "deleted").
Deletion also could be used to provide momentum should a TARDIS need to escape a threat. The number of rooms that were required to be deleted varied depending on the situation. The danger in architectural configuration was that there was a chance the console room could be deleted. (TV: Castrovalva) There was, however, a failsafe that kept the TARDIS from erasing itself, possibly as a whole. (PROSE: Falls the Shadow)
The Doctor's TARDIS[]
During his exile on Earth, the Third Doctor altered his TARDIS' architectural configuration software to relocate the console outside the ship (as it was too big to go through the doors), allowing him to work on it in his lab. (PROSE: The Face of the Enemy, TV: The Ambassadors of Death, Inferno, Day of the Daleks)
The Fourth Doctor jettisoned Romana's room after Romana II left, when the TARDIS wouldn't dematerialise. (TV: Logopolis) In his next incarnation, 25% of the TARDIS was jettisoned to allow the TARDIS to escape from Event One. In the process, the Zero Room was jettisoned. (TV: Castrovalva)
When Ishtar transmitted her mind into the TARDIS, the Seventh Doctor used the architectural configuration to reduce some of the TARDIS's mass, providing the energy needed to jettison the circuits she had taken over. (PROSE: Timewyrm: Genesys)
When the TARDIS was reconfigured into a SARDIT, the Doctor accessed architectural configuration to trap the Process. He later used it to create a spiral staircase to the Process's Tower. (PROSE: Cat's Cradle: Time's Crucible)
Ace thought that the Doctor lost some of the rooms in the TARDIS, but he claimed it was the architectural configuration in progress. (PROSE: The Dimension Riders)
The Eleventh Doctor used architectural configuration to delete at least three TARDIS rooms - the swimming pool, scullery and squash court 7 - and use them as extra power to move through the bubble universe rift. On the return trip, House used this function to delete an archived control room in an attempt to kill Idris, the Doctor, Amy, and Rory. However, the TARDIS's delete function included a failsafe that deposited any living objects inside of the main control room, saving them. (TV: The Doctor's Wife)
Gregor Van Baalen became interested in the architectural reconfiguration system when his scanner described its value as more than the sum of any currency and decided to steal a part of the system. In response, the TARDIS trapped him in a space loop by turning a door into a wall, and its corridors into a labyrinth. (TV: Journey to the Centre of the TARDIS)
The TARDIS once played a practical joke on Clara Oswald by relocating her bedroom while she was in the shower, forcing her to search its corridors for it. (HOMEVID: Clara and the TARDIS)
Others TARDISes[]
Galah linked her mind to her TARDIS and used its Architectural Configuration Programme to create an artificial universe based on Wychborn House. (PROSE: Strange England)
Compassion's architectural configuration was misaligned after her fall on Eskon. (PROSE: Coldheart)