Factories and Factory HQs

[spooky9]

Can someone tell me what's the difference between a factory and a factory HQ?

[rootbeer23]

factories are cheaper, but you cannot produce tech N units without a tech N HQ.
HQ is more expensive to make later tech levels hard to reach. (same as before)
factories are cheaper because they represent what formerly was engineers assisting the factories.
so normally make one HQ and many factories, and possibly more HQs as backup for when the primary is destroyed.

[Gorton]

I will do so by example.
You have a t1 land factory. You don't have a t2 land factory, and you want to have t2. So you upgrade it.
The upgrade you can do is upgrading to the T2 HQ factory. This takes the normal amount of time and mass to upgrade, as factories did previously, before engimod ( the patch that made HQ and normal facs)
Once you have a t2 HQ, you can much more cheaply upgrade t1 factories to t2, to normal t2 factories. It also takes less time.
If you lose the HQ, you cannot upgrade t1 factories to normal t2 factories and all your t2 factories will stop producing t2 units (except engineers) Upgrading another t1 fact to a t2 HQ will solve the problem.
You can have multiple HQs, if you wish. Nothing stopping you.
The same applies to t3 land, t2/3 air and naval.

[spooky9]

thanks