Fast construction

[LGM]

If you merely want quick initial expansion, design your race to build colonizers in one turn with Emergency build turned on. 10 Colonizers in 10 turns will get you growing fast. I frequently scrap the shipyard after 10 turns and build another mineral facility as by that time, all those startup colonies start depleting the mineral reserve.

Consider increasing shipyard rate based on what you need at wartime. You want Shipyards II and III for wartime, not for initial colonization. With these, you will probably be able to build one colonizer a turn, but at that point, you probably will not be building hoards of them anymore. What you are concerned about is how fast you can build warships compared to your enemy. Here quantity of shipyards can overcome quality of shipyards if you have the superior economy. Think of Cargo Specialists as +20% in all resource catagories (Min, Org, Rad, Intel, Research). Religous Tech III can add another 15% to resources.

If you have colonization limited by planet type or atmostsphere type, you probably do not want to waste points on rapid construction as there are better things to put them on (Propulsion Expert, Ancient Race, etc).

If you really want to build warships fast, Organic tech grants you that quite early on as you use much less in minerals on your ships. Otherwise, you can take Temporal for Temporal shipyards.

If you simply just boast your building capacity up at the expense of your economy, you probably will not have the resources to keep up.

Also keep in mind ship limits in your game. If you are likely to hit the ship limits in the mid or late game, that extra building bonus may be wasted.

I am currently in a game with a 200 ship limit. I have about 90 shipyards, most of them are on hold with base ships with one turn to go. If I loose 50 ships, I replace all of them the next turn, although they are not together. Now my shipyards take about 8 turns to build with shipyards III, but that matters little as I keep hitting the ship limit. I have cheaper dreadnaught designs that I can build in an emergency in about 5 turns. Cheaper weapon and a smaller hull, but more enginers for faster speed.