I have one building but how do you get more?
There are three buildings:
- Pasture: 20 wood, level 2 infrastructure research
- Mill: 30 wood, level 3 infrastructure research
- Well: 50 wood, level 5 infrastructure research
The target field must be empty. All conditions must be met, or the option to build will not appear.
You might also consider a graveyard to be a building, but they build themselves, without requiring any help from you :)
Reference: source code