Build a square 23×23 base using con...

Build a square 23×23 base using concrete or steel blocks, find the exact center block and treat it as your main alignment point, then build walls up to about 13 blocks high while leaving a 3-wide and 4-high opening exactly in the middle of each side so every module can connect cleanly, keep the floor flat and optionally run pipes and cables underneath, make the roof flat with simple vents or slabs, repeat this same module shape every time you expand by snapping new modules directly to those centered openings so everything lines up perfectly in all directions and can scale infinitely without breaking alignment.