How to give animation construction?

FOr non-melee building Dragon Roost under Orc category which doesnt have construction animation, how do I give an animation to it?

You can't without editing the model, but you can use the action:

Animation - Add the work animation tag to <unit>

to make it look like it's doing something :D

The dragon roost doesnt have work animation. How do i add other building's animation to it? is it possible?

i've been wondering the same thing... it seems that some custom buildings i make have animations, others dont... But i cant find any fields that let you edit that...