[douglas]

I just tested this, and here's what I got:

If a ship or planet has a space yard rate of 0 for a resource, that resource will be completely ignored for contruction. Not only is it all done instantly, you don't even have to pay for it. Other resources must still be paid in full at the appropriate rate, however.

If all three rates are 0, whether through a space yard ability with 0 rate or the complete lack of a space yard ability for that resource at all, no construction gets done at all.