At game start people will be living in wooden structures with thatch roofs for the most part but with some people being able to afford crude constructs made of stone.
People will also have a general idea of what causes buildings to collapse, however this is not very rigorous to begin with and could have effort applied to it in order to ensure building collapse is reduced.
These are some of the things you might making in the future. Of course, it is perfectly possible to devise your own ideas of things to invent and develop. It is important to note that discoveries must follow a path of progression; it would be impossible to invent reinforced concrete before concrete, for example.