Anyways, with the help of Pier Pjanssen I've made a map of all the levels of Minas Tirith.L1, L2 etc. indicates Left level 1, Left level 2 etc.
R1, R2 etc. indicates Right level 1, Right level 2 etc.
M-7 indictes the main top 7th level which includes the courtyard, The White Hall and the Tower of Ecthelion(if I'm not wrong).
The house(or a certain group of houses) will be given a certain number. For eg. a certain house on the left level 1 might be L-1-20.
Since we do not have an actual idea of how big Minas Tirith is, in the real sense, we can use this to scale depending on how big we want the model to be. To get the idea of the scale and proportions of the heights of each level and the walls, I'll be posting another image later on.
I still don't have a team people!