Pfeffersack
Deity
Another small detail and this time also something contradicting the civilopedia description of the mode:
The "existing improvement" is not a mandatory condition (or at least poorly worded), as you can build the Industry improvement even on a unimproved ressource, as long as you somehow fulfil the condition of having access to 2 sources (be it by having the same ressource already improved twice elsewhere and/or from a suzerained CS):
This can save you - given you have sufficient time and ressource access - a builder charge.
The "existing improvement" is not a mandatory condition (or at least poorly worded), as you can build the Industry improvement even on a unimproved ressource, as long as you somehow fulfil the condition of having access to 2 sources (be it by having the same ressource already improved twice elsewhere and/or from a suzerained CS):
Spoiler :
This can save you - given you have sufficient time and ressource access - a builder charge.