Decomission vs. upgrading to something different

The only reason to decommission is if you want to strip the planet of improvements because you're about to lose the planet.

If you're upgrading a building within the same type you get full credit for the previously built building. If you're upgrading to a building of a different type you still get some credit for the money spent on the previous building.

Thanks for the answer Mumblefratz.
Getting credit back? Never noticed this, I will have to pay more attention.

But... buildings don't cost any credit, only manufacturing social points, right?
What do you mean with this? Do I get part of the maintenance back?

No, but the manufacturing points carry. Which means upgrading factory - advanced factory would be quicker than decommision and then build advanced factory.

Hope that helps.

Ok, yes this helps.
So, an upgrade will carry over all points of the previous building's version.
And building another type (e.g. market) on a factory will cary over only some of the points.

I was always doing it the wrong way then!
I decomission a building if I decide to put another type on a tile.
By mistake, I discovered that it's possible to build another type without decomissioning.

Thanks to both of you, my next game will be better

Are you sure you get partial credit when replacing one type of building with a different type? I have never noticed this happening.

Are you sure you get partial credit when replacing one type of building with a different type? I have never noticed this happening.

I just checked it out in the game. I first verified that basic factory (50SP) upgraded to factory (75SP) within two weeks at 15SP per week, so that checks out.

I then checked basic factory (50SP) upgraded to basic lab (40SP) this claimed to take 4 weeks (should be 3 at most?). Just building a basic lab on a free tile was also 4 weeks. I then checked out extreme stadium (250SP) which took 16 weeks to upgrade from basic factory and 20 weeks to build on a free tile.

To me it looks like if the building your upgrading to, is cheaper than the building that's already there, then you don't save anything over building on a free tile, but if the building you're upgrading to is more expensive it actually looks like you get full credit.

There also seems to be discrepency in number of weeks to complete reported in the planet screen and the number of weeks to complete in the colony list of the civilization manager screen. The civilization manager colony list appears to be correct. (This has been discussed in other threads). If you use this, the difference in upgrade vs. buy is 3 weeks which at 15SP's per week is at least 45SP's. Since the basic factory is 50SP's it looks as if you're getting pretty much full credit for upgrading a lower cost building for a higher cost building.

You can verify this in-game yourself in a similar manner. You can get the costs of the buildings from your PlanetImprovements.xml file in the GalCiv2\Data\English directory.

Are you sure you get partial credit when replacing one type of building with a different type? I have never noticed this happening.

Under 1.2 before morale buildings were nerfed I used to have 2 or 3 on every planet with tax rate bumped up to 80%. What this meant was when I captured new planets I often had to build an entertainment building as a matter of priority or lose population to low morale. I also had 100% tech spending and was using focus buttons for social production so if the planet had few labs on it I had very little social production. Upgrading buildings was much quicker than going for new tiles, and upgrading factories was quicker than upgrading labs.

One easy way to tell...look at the cost of buying the upgrade and compare it to the cost of buying on the fresh tile. The fresh tile purchase is way more expensive.

Thanks for the extensive report Mumble.
I will look into this next time I can play a game... RL is getting on my nerves