After confirming 'Yes' to the 'Build now?' message the user is not given the option to choose which raw materials to use. It would be beneficial to show the same screen as seen when producing goods and a choice of materials are available (the 'Please choose the appropriate raw materials.' screen).
In my case I built a Plantation in Mauritania and wished to use my quality 3 steel instead of the quality 2 that was chosen automatically. Likewise, the same occurs with wood.
I have not attempted to reproduce this, but I'm pretty sure the function is just not implemented.
Thanks for this, keep up the good work!

Playmaker Inc - Realm 2.