I made a little excel spreadsheet to help me plan out a lair and thought I'd share it. It shows the dimensions of each room and where all the attach points are. Enjoy.

Lair Pieces

edit: Each square is a 24x24x24m block. So if you have a 120x120x144 lair then you have 5x5x6 blocks to build in. (not counting whatever you can fit in the extra 0 level)