Thanks guys for the answers, so I guess the secure build would be:
Hangars/workshops/radars/entryway/everything else, with the alien containment being as far away as possible
perhaps this info should be in the ufopaedia?
also any priority to soldier spawns? (i.e. they spawn mostly in command ,or all over, etc.) I never actually encountered a base defense mission, probably since I'm playing on very easy since I have limited time