Also know your compositing skills (photoshop, after effects, etc.) is a plus... if you did something wrong, client doesn't like a specific material, architect is crazy... whatever it might be, this has made a big difference down the line. Yeah, 2 extra hours up front... but it will save you hour or days of additional work in the future.
Most important though... being good at modeling. Remember (since this is CGArchitect), architects are never happy with a final result and want to change everything all the time... build models based on ease of editing in the future.