Thank you very much for your respond, laszlonagy.
You're right about the wall length being shorten and it reports correctly in the Element Info. palette as "Conditional length on the inside face = 1.0007 m" for the selected wall.
What I am looking for is that...Apart from WALL_LENGTH_A and WALL_LENGTH_B, is there another parameter (or variable, sorry for my messed up terminology) that gives off the "Length of the Reference Line" which has the same value whether there's another curve wall at the other end or not.
Sorry I didn't make myself clear the first time.