The Building Screen contains a list of available buildings with pictures and descriptions. It will say after the buildings name what level the building has currently been built to. The cost of building the next level, as well as the amount of time it will take are shown under the description. You can build the next level building by clicking on the Build or Upgrade to Level X text to the right of the building. Bulidings can be cancelled by clicking the canel button next to the construction before construction is completed. All resources are returned to the planet's available resources.