So I made a new faction and I want the game to generate buildings tooin its regions. I understand that a building is defined as a ship with no thrusters and a root block. I already have such a design. But the game still isn't generating my buildings. I noticed that the Bee faction's buildings have a command module named "subcommand" and has only the COMMAND Aiflag. While I am using the usual command module, with thruster, torquer etc Aiflags.
What am I doing wrong?
P.S My building design is correct. I can Metamorphose into that design, but the game doesn't generate it in my Faction's regions.

Assuming that you have asteroids and faction structures enabled in your regions.lua file, do note that there was bug where expensive buildings do not spawn. I don't know whether that bug is still around, but that's a thing.