Answered What happens if I upgrade a building with production in progress?

[Starbladder]

If I upgrade a building with production in progress, do I get the resources already allocated back?

It does not look like I get them back, so at least a warning dialog would be nice...

 

[DeletedUser]

There is a warning when you upgrade a building (expect residences) and a production is in progress that the production will be cancelled

In the workshops you won't get anything back (because they are free to start)
In barracks/factories you get back what you paid for the production when you start an upgrade

 

[Starbladder]

Thanks for clearing that up.
It also looks like if you upgrade barracks then any pending slots restart from the point before the upgrade - in other words any queues will resume

 

[DeletedUser]

Hm.. good to know, thanks. I didn't upgrade the barracks yet with units producing. Only the others

 

[DeletedUser18]

Both points are correct.
Upgrading a building in the middle of a production cycle whether supplies, military units, goods or even coins before they are collectible will cancel the current cycle and the progress will be lost.