# How is the number of engineers required to build facilities calculated?

I've noticed that the number of engineers required to build subsequent facilities (e.g. a second satellite uplink) is larger than the number required for the first facility. What factors determine the number of engineers required?

• this may be dependent on the building. I've often been able to build a new workshop yet cannot build a new sat uplink, and I think sat nexus requires more engineers than uplinks.
– l I
Oct 29 '12 at 12:33
• Are you sure the cost didn't grew due to the fact that you built your 2nd nexus on a lower level than the first? Oct 29 '12 at 15:23
• @ShivanDragon yes I am building at lower levels, but is that the only factor involved? Oct 29 '12 at 21:28
• @jwaddell well, as you build deeper the prices and maintenance costs go up. I've not noticed a price going up for a building ONLY because you already have some instances if it, but I may be mistaken Oct 29 '12 at 21:32

The number of engineers required for facilities depends on the number of similar facilities that have been previously built. (It appears engineers in the new XCOM are capable of working on an infinite number of tasks simultaneously, provided the tasks are sufficiently different from one another.)

Six engineers are required to build the first workshop, fifteen for the second, and ten additional for each additional workshop, the number of scientists required per laboratory is similar.

For satellite uplinks, the formula is (10 * SU + 15 * SN), where SU is the number of satellite uplinks already built (or under construction), and SN is the corresponding number of satellite nexuses. That is, you need ten engineers per satellite uplink, with the first uplink (already built at the start of the game) being free.

For satellite nexuses, the formula is 5 + (10 * SU + 15 * SN).

If we ignore adjacency bonuses, as nexuses provide double the uplinks for half again the number of engineers, this means the engineer cost of satellite nexuses is lower per satellite.

Factoring in adjacency bonuses, the upper limit is four satellites per uplink or six per nexus: each facility can particpate in four adjacency bonuses, but each adjacency bonus is shared between two facilities, so we get maximum two bonuses per facility. This 4:6 uplink ratio equals the 10:15 ratio of required engineers, so an infinite plane of satellite uplinks would provide the same number of uplinks per engineer as an infinite plane of satellite nexuses.

Since we'll never come close to approximating an infinite spread of satellite uplinks, in practice, nexuses will always have a lower engineer cost.

However, since they require alien materials to construct, and since having more engineers lowers the quantity of both money and alien materials needed to build everything, if you're short on materials, it's better to aggressively push the number of engineers, and build regular uplinks, saving the alien materials for armor and weapons.

If, on the other hand, you have a surplus of alien materials, the lower engineer, power, and space requirements of satellite nexuses provide more uplinks faster, and cost fewer credits.

It's not related to location - it's fixed based upon how many of the same type of building you already have i.e. the first Workshop requires 6 engineers, the second 15 engineers, the third is 25 engineers and so on... (I can't remember the rest - but it is fixed).

edit: having played another game - I noticed it increments workshops by +10 engineers per workshop, so the 4th is 35 engineers, the 5th is 45 engineers and so on...

• Does difficulty play into it? Oct 31 '12 at 2:42
• No - I've played Normal, Classic and a bit of Impossible, and its always 6 scientist/engineers to unlock the first lab/workshop, and 15 to unlock the second. After that I'm not 100% sure - but it doesnt seem to change. Oct 31 '12 at 3:45
• fyi it climbs fast, I've seen a requirement of 60 engineers to build a sat nexus.
– l I
Nov 1 '12 at 13:03