 There are a number of reasons for the use of an indoor studio; the main one being that the infancy of production techniques at the time did not allow easy recording and editing of sequences filmed in different locations.It was not until 1967 that editing techniques had improved enough to allow "Coronation Street" to be filmed on separate interior and exterior sets.The studios were not big enough for the entire street to be erected at once, so it was split into two halves.