David,
Sorry I don't remember the thread title, but there was a long discussion about RH and TT planning in the Track Planning sub-forum recently. The crux of the discussion was how much space it took to use certain sized TTs and RHs together within the planners space restriction. I believe the conclusion was reached based on the size of the structures and the distance required between the structures to have each stall's track reach the TT in some reasonable manner. The primary factors governing the distance between structures were the size of each stall's doorway and the angle at which each doorway abutted the one next to it. Thus, your 3 stall RH might work fine at a set distance from the TT, but increasing the number of stalls to 6 or 9 might require a distance or trackwork (complex with frogs near TT) change.
Suggest you draw a model of current base and add it to one side of current RH, layout track centers to TT, and see how it all lines up in available space before adding more stalls.
Chuck
