as a reminder:
with standard SHIFT + TAB in the game the Steam overlay and thus the guides can be showed up.

there seem to be some differences in the quantities (at the moment) > other players had different quantities in some cases.

general building rewards: selling prices all seem to be (somewhat) higher than normal.
construction time: mill approx. 2 years, castle approx. 4 years
- mill construction reward: functioning grain mill
- castle construction reward: crown as a personal equipment item