From the Publisher:
7 Wonders: Edifice gives players the opportunity to work together to construct communal buildings. If you do your part and the building comes to be, you'll be rewarded. You don't have to participate, but if you don't — and the building never comes to be — you'll suffer a penalty.
In more detail, this expansion contains fifteen edifice cards: five each in ages I, II, and III. To set up, choose one card from each age at random, then place it project side face up on the table and place 2-5 participation markers on each card, depending on the number of players. The project side lists both the potential reward and potential penalty.
7 Wonders: Edifice contains two new double-sided wonders; one of them, Ur, can only be used with this expansion, while Carthage can be used in any game of 7 Wonders.
7 Wonders: Edifice can be used with any edition of 7 Wonders.