I watched a behind the scenes documentary on Brookside years ago that showed the ' tricks ' of filming it and things like the bedroom closets were used for equipment to be placed and cameramen to position themselves in with the doors open to record the scene - and I think they just used as few cameras and as small ones as possible
If you mean why they chose to do this or managed it financially, Phil Redmond worked out some deal with a housing corporation to buy a whole culdesac of houses that worked out more cheaply than building sets in the beginning of the programme ( I think the houses were in the process of being built or something, rather than being specially built for Brookside )
A Distorted Reality Is Now A Necessity To Be Free