Honestly, I think that the low hp and effective range of alien buildings makes constructing them very fickle. Only one alien building has the hp of the Human counterpart, the egg/repeater. Don't say aliens do more damage, because all the alien defenses can be easily killed from outside their effective ranges by many weapons. Buildings placed on walls or ceilings will not work against more experienced players. If aliens are to become more base dependent in 1.2, they will need more dependable bases.
For reference, structure hp comparison:
Main Power:
[A] Overmind 750 hp
[H] Reactor 930 hp
Auxiliary Power:
[A] Egg 250 hp
[H] Repeater 250 hp
Spawns:
[A] Egg 250 hp -
[H] Telenode 310 hp
Team Resupply:
[A] Booster 150 hp
[H] Armory 280 hp 1.1.0 (420 hp tjw)
[H] Medistation 190 hp
Defenses:
[A] Acid Tube 125 hp
[A] Barricade 200 hp 1.1.0 (300 hp tjw)
[A] Trapper 50 hp
[A] Hive 125 hp
[H] Turret 190 hp
[H] Defense Computer 190 hp
[H] Tesla Generator 210 hp
Misc:
[A]Hovel 375 hp