[esp-r] atrium modeling

[NALIN SWAROOP]

Hello all

I have to model a 8 storey building with an atrium going from ground floor
to top floor.This atrium has the staircase which will be connected to
every floor i.e every floor has its entry from the staircase.
How should I go about modeling this in ESP-r? should I use autocad or is
there an easier way to model this in ESP-r? and how should I define the
zones?

Sincerely

Nalin