If you click a upgrade, the already bought buildings CPS won't change. TIP: You might want to get the 5% CPS in late game. EX. having 100 CPS will only increase it by 5 CPS.
j3or for the sprites (buildings) Oh yeah, thanks for user4567 for the backdrop. CC Wiki for Upgrade pictures. Orteil owns cookie clicker, this is just a scratch version, Etc.
