Building Optimization (EU2012)

Your base is a 7x4 grid of spaces for construction. The center row is reserved only for the ACCESS LIFT, which leaves 24 spaces you can build on (though three start prebuilt). You cannot build at a level that does not have an access lift. While some squares may start empty, most will be filled in with rock, which must be excavated (taking 5 days) before any construction can begin. Some squares will also contain Steam, which allows building Thermal Generators, which provide more than three times normal generator's power for the same power/money ratio.

Digging deeper costs progressively more, but Steam Vents are usually situated further down; also, more dimensions allow you to take more advantage of Adjacency Bonuses earlier in the game. A good example is to build down to a steam vent early, build a Thermal Power Generator, and then build normal Power Generators adjacent to it to maximize the efficiency.

Full Base Layout Analysis

Following analysis is based upon Classic/Impossible difficulty levels and building no more than 4 Workshops, 4 Labs total (which is usually quite enough), and building enough satellite facilities to cover all countries.

Space Management

You have 28 spaces total, 4 of which are used by access lifts. Out of remaining 24, 14 will be used by special facilities, labs and workshops, which leaves 10. This means you have 10 tiles remaining for your power and satellite facilities. Thus, you are not actually constrained by size in the endgame.

Building an Access Lift down costs a fixed $ 50 and 2 Power, but excavating costs progressively more - 10 for level 1, 20 for level 2, 40 for level 3, 80 for level 4.

Power Management

You start with 30 power and will need no more than 98 for your whole base (if you build 4 Sat Uplinks, 1 Sat Nexus, that reduced to 96 if you build 2 SU and 2 SN). Thus, you need to get 68 additional power from your generators, which means that two Thermal Generators and one Elerium Generator, located anywhere (not necessarily adjacent) will solve all your needs. In case you want two more workshops (total of 6), you'd need those Generators to be adjacent, have an additional Power Generator, or have two Elerium and one Thermal Generators located anywhere.

Adjacency Bonuses

Adjacency bonuses are awarded once for each pair of facilities that are adjacent to each, which means that square formation is the optimal formation for facilities that have adjacency bonuses, since this is the only formation that will provide you with four adjacency bonuses per four facilities built. Since you have to build an access lift in the middle, you are left with space for two squares of facilities and 4 individual facilities on each side of the lift.

No matter how tempting it may seem to build an optimal base like this, arranging satellite support, workshops and labs in squares, the cost of such undertaking will be a huge deterring factor. Since you absolutely need workshop, power source and satellite facilities from the very game start, you would have to excavate to level 3 right at the beginning, which would cost you extra 4 power and $ 140 (effectively, $ 180), plus extra maintenance for the extra access lifts. Therefore, it makes sense to have one of the three to be built in another formation.

Getting satellite adjacency bonus is absolutely a must, because 1 more satellite support is always worth it up till you cover the earth, however after you get 110% faster research from 4 labs and 3 adjacency bonuses, 10% more is only 2.4% increase in research speed. Between workshops and labs its a matter of personal preference.

Satellite Coverage

To get complete satellite coverage, the most economical setup in terms of base space is two Satellite Uplinks and two Satellite Nexus arranged in a square.

However, if you build 3 SU and 1 SN in a square, you get support for 14 satellites. Since you need to support 16 satellites total, and on higher difficulties you are most likely going to lose countries, this seems to be a viable alternative.

Also, you're not constrained by base space really, and building a Satellite Nexus early (after you have only two Uplinks, meaning month 2 or 3) is a serious undertaking (it takes more time and needs more engineers and power up front). Thus, it might be a good idea to build 4 SU first in a square, and then add a Nexus anywhere in the base, giving you coverage for all of the 16 countries.

Furthermore, if you consider the fact that covering whole earth stops Abduction missions from happening, you might aim to cover all continents except one, leaving that continent up for abduction missions. Therefore, you may skip building the Nexus completely and just go with 4 SU, or with 5 SU if your remaining continent has less than 4 countries.

Removing Facilities

Not every facility can be removed.

• You can never remove Access Lifts, Hyperwave Relay and the Gollop Chamber.
• You cannot remove Power Generators, if that would put you in negative remaining Power.
• You cannot remove Satellite Uplink/Nexus if that would put you in negative remaining Satellite capacity.
• You cannot remove Workshops, if subtracting five engineers that come with it would take you under the number required for one of the other facilities present.

Even though Alien Containment, Foundry and Officer Training School could be removed, doing so will remove the bonuses they provide.

• Any aliens not yet interrogated will die if Alien Containment is removed.
• Foundry and Officer Training School perks and bonuses cease to work until their respective building is rebuilt.

Conclusion

• Leave space for a square formation of Satellite Uplinks to the left of the Access Lifts on level 1 and 2. Aim to build a Satellite Uplink every month, and cover every continent except one as soon as possible to have no more panic management.
• After you have four Uplinks arranged in a square:
  • If you do not wish for abduction missions to cease happening, either just have all continents except Europe or Asia covered and leave one of those two uncovered (in this case, 4 Uplinks are enough), or if your last continent has less than 4 countries, build an additional Uplink anywhere on the base to support extra 1 or 2 satellites.
  • If you wish to cover all the countries, build a Satellite Nexus anywhere.
• Aim to build Workshops in a square formation to the right of the Access Lifts. If you need to conserve space early, you can build a Power Generator in place of one of the 4 tiles of a square, and remove it later when you need to place the fourth Workshop.
• Build early Power Generators in remaining tiles on level 1 and 2. Start getting Thermal ones as soon as you have reached Steam and can afford it, and stop when you have built 68 additional units of power (less if you don't want to cover all continents, 74 if you want 6 workshops).
• Place Officer Training School, Foundry and Alien Containment somewhere where they can stay for the rest of the game. In case you need to move them, moving Alien Containment will hurt you the least, and moving Officer Training School will hurt you the most.

Other Considerations

Officer Training School on Easy and Normal

On Easy and Normal difficulties, you automatically start with the OTS built. However, you cannot acquire any of the bonuses until your soldiers reach the necessary ranks. The OTS is always placed in the upper leftmost corner of the basement, and the first Satellite Uplink is likewise always placed to the immediate left of the first level Access Lift, with the space between the two excavated. If you tear down the OTS early on, you can get three linked Satellite Uplinks without ever having to drill down to the second level, and without ever having to excavate. This is quite a bit faster and cheaper than getting two, then drilling and possibly excavating for the third.

This rapid expansion may require a power generator to be built on Normal, but on Easy you should be alright.