CT House Rendering

Hi, sorry i have a question thats bothering me to do with designing and i thought i sould as u as you use the same programs i do. Im a architecture student and my issue is i usually get a design idea by designing and modling with phyical models and 3ds modles to get the shape then after i draw it up in CAD. I cant do it the other way round as like design it in CAD then follow it up. And well i usually design in sketchup and import to CAD but ive been practising with 3ds Max and i want to use it for better looks like your self. So im wondering is it hard to design a whole building in 3ds max, do you recommend just using for inteior shots or do u think its suitable for the whole building taking into account rendering times, amount of details in it (may lag up comp) im just really not sure how to do my usually design process taking into accound 3ds max.

If you could just tell me what you usually do and what methods you recommend I will be super GRATEFULL ^.^

Thanks for ur time.