Not gonna happen, sorry.  This is something that has come up time and time again, and mostly for game balance reasons, the devs aren't going to break the One Turn One Thing Built paradigm.  

What you do get is production and research overflow.  So at least it's not wasted.  But the ability to spam out 20 snubfighters every turn would have SERIOUS effects on game balance.

Which is probably why it is very rare for a turn based 4x game to allow it.

Well make it an option? I think its insanely annoying and unrealistic :/, civ 4 allowed it, among other 4x'ses , in a game that makes such a big deal out of specializations of planets, you should be allowed to produce multiple stuff per turn .

Also why can't you build the higest level of a building first any longere? I miss that from galc civ 2, and why are all prod and resarch building percentage based instead of a flat bonus?

But hey, overflow is nice  

You're right of course how can they have something so unrealistic in a game that has force-fields, Hyper-drives and ships trapped in pocket dimensions  . All production taking at least one turn is your realism concern, really??

If you allow building more than one thing, than there is immediately the problem of what should be build. So you have 100-Zillion production points on one shipyard - meaning the shipyard could produce 1000 tiny ships in one turn. Nice. But it would be even better if it produced 10 small ships, 2 medium, 1 big ship and a carrier so that you have a balanced fleet. That opens all sorts of problems with the production queue, the UI and I guess also with the AI.

I think the solution is to make things more expensive and maybe have diminishing returns if planets get in really high regions of productivity.

But I also think at the end of the day it is OK if you can max out a planet so far, that it has more production than you are able to spend. It just should be rare and hard to reach.

I support planets sponsoring multiple shipyards.

You know you can build more Starports?

I do not think I ever remember any 4x game that I played to let you push out more than 1 unit per turn. I do not even know why this keeps getting brought up.

A vocal minority does not mean much.  Nor if the same people are asking over and over again.   

Besides, it's not as simple as throwing a switch or altering one line of code to allow this.  Allowing more than 1 thing per turn (which, despite the one example of Endless Space, is exceedingly rare for a TBS 4x game) would mean tailoring the AI strategies so it took advantage of it (and one look through the forum should show how difficult that is).  It would mean rebalancing costs for buildings and ships.  It would mean tons of testing to make sure that it didn't break the game.

Now, I get it.  Some people really really want this.  Well, if you don't want to "waste" "thousands" of units of production in the late game..... Don't design planets that will produce that many production units.

And I don't mean that to be flippant (well, possibly only slightly ).  I mean that so one doesn't set up Uber Death Planets if one is only going to get pissed off by them late in the game.  Or, once one does find one "wasting" "thousands" of production units, repurpose the planets to do something else. Turn them into money planets or culture machines.  Or even diplomacy bombs.

Or....  Or just suck it up and get on with crushing everyone else.  Because I tend to think if one is at a point where one is wasting thousands of production units, one is at the ho-hum, nothing challenging here stage.

One has to be careful though not to "lock out" either casual players or folks who aren't taking "full" advantage of adjacencies and souped-up buildings by making buildings/ships too expensive.  It's the classic problem of Power Player versus Casual Gamer (which is more of a spectrum, but I digress).

Still, if folks think it is too easy to build things late game and/or think buildings and ships should be much more expensive, send your save games to Stardock so they can take a look at things for themselves.

Though if they end up changing things and that in turn means that things will cost waaaaay too much for this not-exactly-a-super-power-user, I reserve the right to be slightly cross as a result.

Good discussion here. I would like to see multiple ships per turn as well. It would considerably reduce the amount of micromanagement required. Right now, the gameplay is simply not built around the massive map sizes that the game offers due to the amount of micromanagement involved. The shipyard sponsor system isn't as helpful as it could be simply because planet's with reasonable production will often need their own shipyard anyway. I hope Stardock plans to address these late game/large map balance/usability issues. As much as I enjoy the game, these core issues could use a lot more polish before continuing to expand the scope of the game through DLC/expansions.

I would argue that the one unit per turn is a good argument for not specialising all of your planets so heavily.

Without specialising them so much, you could have a lot more Spaceyards being sponsored by many planets different planets late game with moderate Manufacturing instead of only a few with crazy high Manufacturing - thus making better use of the total empire Manufacturing and wasting less.

Again.  Particularly in a large map, you're at a strategic disadvantage if you only have "Hub" production worlds, because anything away from that Hub is screwed. Doesn't matter if you can pump out SuperMegaShips by the bucketful, if you've got only a handful of those worlds in a 100-world, 400+ hex-spanning empire. Any decent opponent will Hit-and-Run you to death, because you can't get your forces to the attack points in time, as, inevitably, you'll not have your production worlds near enough to the front lines to rely on them for the majority of your ship production.

Far better to scatter that production across 3 times as many worlds, and make those worlds far more distributed.

Plus, in this game, the layout of tiles means that you'll generally NOT have all tiles in a single cluster (even after terraforming quite a bit), but rather 2 or 3 tile clusters. Which means that multi-purpose worlds will be better (and easier) in the long run to manage and give value (since, given the bonus tiles, you want to take advantage of them maximally).

Honestly, other than really low-tile-count worlds, I never understood single-purposing worlds as a good idea.

I didn't say generalize, I said avoid single-purpose specialization.

Even avoiding the 1-thing-per-term limit, you're better off with a planet that makes maximal use of the bonus tiles and adjacency bonues, which means in the vast majority of cases, you'll have TWO primary functions of a planet.

Remember, there's at least 6 different kinds of things a planet can do:

(1) Manufacturing

(2) Research

(3) Wealth

(4) Tourism

(5) Military

(6) Influence

And that doesn't count Approval and Population.  Let alone special-purpose things like getting Ideology points, Diplomatic bonuses, etc.

If you want to max the benefit from any one of those 6, you'll have to make at least 3-hex clusters.

Overall, planets which spam a single type of building are less efficient than the same number of buildings distributed over several worlds, because you miss out on key adjacency bonuses if you overdo just one building type (since, inevitably, you put a building next to a bonus tile which is not the correct type - if you building spam, that is).

While you can pump all that production into a single shipyard, you're better off having more shipyards, as you're less likely to have the loss of a shipyard negatively affect you, you're more likely to not lose production due to distances, and you can produce more than one ship per turn with multiple shipyards.

That is, it takes longer to produce a given ship, but you'll produce more TOTAL ships with more shipyards than a single one with multiple sponsors. There's a fine line to walk, but the advantage generally falls to the "more shipyards, more total ships/turn" method.