text: Filming The majority of EastEnders episodes are filmed at the BBC Elstree Centre in Borehamwood, Hertfordshire. In January 1987, EastEnders had three production teams each comprising a director, production manager, production assistant and assistant floor manager. Other permanent staff included the producer's office, script department and designer, meaning between 30 and 35 people would be working full-time on EastEnders, rising to 60 to 70 on filming days. When the number of episodes was increased to four per week, more studio space was needed, so Top of the Pops was moved from its studio at Elstree to BBC Television Centre in April 2001. Episodes are produced in "quartets" of four episodes, each of which starts filming on a Tuesday and takes nine days to record. Each day, between 25 and 30 scenes are recorded. During the filming week, actors can film for as many as eight to twelve episodes. Exterior scenes are filmed on a specially constructed film lot, and interior scenes take place in six studios. The episodes are usually filmed about six to eight weeks in advance of broadcast. During the winter period, filming can take place up to twelve weeks in advance, due to less daylight for outdoor filming sessions. This time difference has been known to cause problems when filming outdoor scenes. On 8 February 2007, heavy snow fell on the set and filming had to be cancelled as the scenes due to be filmed on the day were to be transmitted in April. EastEnders is normally recorded using four cameras. When a quartet is completed, it is edited by the director, videotape editor and script supervisor. The producer then reviews the edits and decides if anything needs to be re-edited, which the director will do. A week later, sound is added to the episodes and they are technically reviewed, and are ready for transmission if they are deemed of acceptable quality.