Is it necessary to upgrade all buildings?

[david_mini]

Is it necessary to upgrade all buildings?

Sometimes I really think it't not worthy to do it.
For instance, I have two stables, one is the highest level (5), the other is level 2.
But the output of level 5, in most case, is even lower than level 2, except for saving a little time......

[jtm101]

Some goals later in the game require collection from Level 5 buildings. Other than that its not really worth it. I find it handy to have them at the same level, especially resources. The librarys are good to upgrade as they will drop spellbooks and bestiarys at a better rate.

[shambalaya]

It is definitely worth it, but of course you have to prioritize your resources. An increasing number of quests requires you to collect from high level buildings, though as far as I remember there has not yet been requirements for the basic resource buildings (stable, hatchery, saw mill, regular mine). Correct me, if I'm wrong?
Aside from quests, if you play this game often the decreased collection time is just soooo sweet!