Back after a long absence, starting up with FTB Infinity and well into early game
So .... I have a nice expansive Highlands plateau picked out for my base, but how much space should I plan for
- Witchery (is it mainly outdoors-ey and do I need to be close to one of those stonehenge structures?)
- Thaumcraft (latest version has new node mechanics - do i need additional space for manipulating nodes and any new machines?)
- Botania (assuming a garden shed and a good deal of outdoor space)
Witchery has the largest footprint of those three mods by far. You'll need a 15x15 area for the circles, as well as a whole bunch of trees, crops, grass, flowers, and any other plants you can find to power your altar. I don't know how much space it needs precisely (depends on how dense the plants are, I guess), but it probably needs more than the circles. The altar does have a maximum range for how far away plants can be and still power it, but I don't know it off the top of my head. Probably on the wiki, though. Even then, you probably won't need to use all that space if you're willing to pack all the plants in more densely.
For Thaumcraft, you'll want space for a 7x7ish infusion altar, with about 50 jars stacked up around it. You'll probably want to stack the jars two high (since that's how high the golems you're likely to use to fill them can reach), so that's about 25 square blocks around the edges of your infusion room. If you leave, say, two blocks of floor space between the altar and the jars to give yourself and your golems enough space to move around freely, you've got yourself a 13x13 room, at least. You could do it with an 11x11 room, but it'd feel pretty cramped.
Oh, and you'll eventually want to spam candles and skulls and such around the altar. But that works just fine underneath the floor or higher up on the walls.
Also, you'll eventually want to have a wand recharger with a bunch of stabilized nodes around it. But you can lay that out basically however you like. Also note that if you put the nodes far enough apart (four blocks of space between them is the minimum IIRC), they won't bully each other, so you don't have to stabilize them, so they'll recharge faster. You should be able to space out 64 nodes around the recharging pedestal this way, if you're willing to devote a 16x16x16 block space (17x17x17 if you want the pedestal in the exact center) to it. Or you can just cram all the nodes together and stabilize them, either way.
Botania actually has a pretty small footprint. As you start on it, you'll want to have a dozen dayblooms and maybe nightshades out under the sky, but once you get fancier flowers, you won't need them. Unless you like having passive mana generation with dayblooms, nightshades, and hydroangeas, in which case you can make as big a garden as you like (Hmm, I wonder if Botania flowers can power the Witchery alter... probably not as well as trees, although it might be worth looking into. Just note that the dayblooms/nightshades probably won't produce mana when shaded by leaves.). The biggest multiblock to my knowledge is the Mana Enchanter, which is no larger than 7x11, and may be a block or two smaller in each direction; I don't remember the exact size.
If you ever get into Blood Magic, you'll want to leave a huge amount of space space open for the Blood Altar. The tier 6 altar requires a 23x23x9 block space, although it works perfectly fine if any or all of it is buried underground. Keep in mind that each tier adds a layer of blocks below the previous tier, so if you want the whole thing above ground, you'll want to start with your Altar fairly high up. Then again, if you want the altar block itself at ground level and everything else (save the pillars) below, that's fine, too.