If I were building a huge defensive installation in space, not something puny, but truly huge and capable of housing tens of thousands of people, I'd probably start installing weaponry as early as it made engineering sense rather than once the rest of the station had been constructed. With something on that scale, there's really no reason to assume that the weapons can only go online once construction have finished since it is a station being put gradually online as different segments are done. If one were a stickler for detail, it might make sense to gradually increase the firepower during the construction, but a starbase under construction going weapons hot makes excellent sense.

As for attacking them under construction - that's entirely intentional and, in fact, makes for interesting tactics: you need to defend a starbase under construction if doing it in a hazardous area. Moreover, if they were not attackable under construction, you'd have serious problems since people could just dump a new starbase in their opponents gravity wells forcing them to have forces on hand to deal with the starbase at full strength once it finished. A "you aren't going to make huge constructions in our airspace, bub" mechanic.

The attacking a structure while under construction is normal and has been with the game since day one.

As for the starbase attacking before construction completed, I believe that it shouldn't be the case. Like with any other struction dosn't become active, the starbase should not be able to activate or attack or give any bonuses till after it is completed. But that is my opinion, and the starbase is pretty darn week in it's basic form, so just send in the armada and blow the sucker up! Problem solved.

Thought so, was having a brain dead moment.

Peter:  By your logic, shouldn't turrets then start firing the moment their construction starts?

They can fire there wepons while under construction, I think thats fine, because in movies and shows starbases underconstruction could fire the weapons on it. It makes perfect sense that it could do that. But the damage amount should be reduced based how far it was built.

No. Turrets are fairly small installations with, most likely, a small crew. They are constructed by crews from a construction vessel. How far on in its construction will it need to be before it houses a crew, has ammunition supplied, and has any weapons installed? Most likely, very far in.

A starbase is citysized (actually, significantly bigger than many cities if you consider that we can upgrade them with modules to house billions of people). While it isn't that big when the construction starts, we are talking about something so huge that it is constructed by an on-board crew of thousands - or tens of thousands.

In both cases, some of the superstructure would need to be built before anything else, but given the vast difference in scale of the projects, bringing things on-line as they are completed during the build process makes much more sense for the starbase than for the turret.

Now, you might well argue and Pezkenin points out that there's no way a starbase early in construction will have all its weapons available; Or, you might argue that perhaps it should only get its first weapons online after 5% or, say, 10% construction is done. I completely agree, after all, I said so already in my reply #1,

If one were a stickler for detail, it might make sense to gradually increase the firepower during the construction, but a starbase under construction going weapons hot makes excellent sense.

Now, in practice that means extra developer work for miniscule gain and the ridiculous situation that you might end up with a handful of frigate sized ships blowing up something really, truly, huge, so given the alternatives, I fully expect the current situation to be maintained as the best tradeoff between what makes sense and what works.