I made another factory. All floors are 3 thick with an air gap as standard for wiring. The interior has been lit up, even between the floor layers to prevent mob spawns.

Overall dimension: 71x37 and 40 tall

Material list:

ars_nouveau:archwood_trapdoor 84

byg:soapstone_brick_stairs 366

byg:soapstone_brick_wall 438

chipped:diorite_1 4

chipped:black_stained_glass_3 15

chipped:cyan_stained_glass_8 461

chipped:cyan_stained_glass_pane_1 40

chipped:sea_lantern_13 96

chipped:stone_1 4305

chipped:stone_7 2860

chipped:gray_stained_glass_pane_1 466

chisel:bricks/solid_bricks 4321

engineersdecor:dark_shingle_roof_block 72

engineersdecor:dark_shingle_roof_slab 1714

engineersdecor:iron_floor_edge_light 289

immersiveengineering:concrete 5021

immersiveengineering:stairs_concrete 741

immersiveengineering:slab_concrete 28

immersiveengineering:slab_concrete_tile 294

minecraft:brick_slab 156

minecraft:brick_wall 608

minecraft:smooth_quartz 448

minecraft:smooth_quartz_slab 248

minecraft:smooth_quartz_stairs 502

minecraft:spruce_trapdoor 7

minecraft:stone_stairs 168

minecraft:torch 97

simplylight:edge_light 81

simplylight:illuminant_gray_block_on 60

simplylight:illuminant_green_block_on 24

simplylight:illuminant_orange_block_on 24

simplylight:lightbulb 8

simplylight:wall_lamp 89