What disables achievements?

[BurningSun]

Does anything other than mods disable achievements? Or do only mods disable achievements?

Also, if I use mods will they prevent me from unlocking unique buildings?

 

[metacritical]

there's a mod that allows you to use mods and get achievements.

to your second question. no

 

[Grapplehoeker]

Does anything other than mods disable achievements? Or do only mods disable achievements?
Also, if I use mods will they prevent me from unlocking unique buildings?

There are only two things that disable achievement eligibility:
Saving a game while there is an active mod.
Accepting a cash bail out.
The unlock tasks for unique buildings are not achievements and are therefore unaffected.

Many of the achievements are easiest to complete in a fresh city build and you can combine some of them to help complete others. So, you can always build a city with as many mods as you wish turned on and build other cities for the purpose of getting the achievements with mods turned off.