Building damage after attack

I think that saving is always a win for the defender, he doesn't lose anything. So I thought about a sort of damage to the structure of the attacked player if he doesn't have ships absorbing damage. Like reducing the production of mines for a certain amount of time and disabling spaceport and laboratory. Like a reconstruction time, during that time the planet "rebuild" its structure and at the end it become fully operative
It will put more strategy in the fight and you have to chose of sacrifice some fleet or sacrifice your production for a while