[Commander G]

Multiple ships yards would be OK or at least allow multiple items to be built in one turn or at least start the next item with left over resources.

The way the game works now, you have to play as Sea Wolf suggests, building orital shipyars on bases. I usually build 3 - 5 myself on my homeworld, depending on how soon I get my hands on a colony with Metal. Once I build enough of these bases, I scrap the planet shipyard (when it has 1.0 years of Slow building) and build something else I need such as a Mineral Mining Facility.

Ship yard bases do cost maintenance, but they can be mothballed when you do not need them.