Special buildings (such as those from events or the antique dealer) do not automatically age up.

For example, in Late Middle Ages you can have access to two recurring quests at the same time if you take precaution with the story line. Prior to aging up, it is important to make sure that you are in a good place in your story line to take advantage of any 'camping' options the next age may have.

Progressing too far on the map can lead to problems, in that it can remove the ability to access recurring quests. When aging up, it is important that your progress on the continent map is sufficient enough that you have boosted goods from that age, or that you can easily reach them. These involve map progress, quest progress, building age, forge point storage, and the availability of goods. There are few considerations that need to be considered before aging up to prevent being in an awkward position. To do that you need to be prepared and choose your timing. It is very important when you age up to do so with momentum.

Forge of empires bronze age strategy