Structures
Without buildings, planets are little more than balls of rock orbiting stars. By using the Building Menu, players can build, demolish, and cancel the structures that make their planet great. Although multiple buildings may be queued to be built, only one building may be built at a time.
The characteristics of the structures you can build are described in List of Structures.
Demolish
Buildings can only be demolished after they are built. Demolishing buildings requires half the number of turns as constructing the building, unless structures decreasing travel time which requires same number of turns as to build them. The orbital or ground space used by the building are returned to the planet; resources are not.
Note: You cannot demolish while constructing
Cancel
Buildings can be cancelled before they are completely built. All resources used in the construction of the building are returned to the planet, as well as any orbital or ground space used by the building.