Hull Construction is the system that replaces travelling to a Shipyard in order to expand. You can enter it at any time while the ship is in flight, entering it automatically pauses the flight, and you are offered a randomly chosen block with empty module slots. There are 15 different construction blocks, they appear in a randomised order with no repeat until the entire set of 15 has been cycled through, and the block cannot be rotated.

How the Hull Rupture hull construction guide works

Enter it from the crossed-tools tab at the lower left of the screen — the rightmost of the three angled ship-view tabs, immediately to the right of the bar-chart Info Mode tab. Entering pauses the flight automatically, which is what makes it usable as a between-wave decision rather than something you have to plan around.

The rules that bind every block

  1. There are 15 construction blocks, and they arrive in a randomised order with no repeat until the whole set of 15 has been cycled through.
  2. The block cannot be rotated. Orientation is part of the deal, so a block that fits badly in one spot will fit badly everywhere.
  3. It cannot block the Airlock or the engine. Both have to stay reachable.
  4. It cannot be destroyed once placed. There is no undo; demolition is not an option for a block you have already committed.
  5. Skipping an offered block costs resources. The offered block is highlighted with its cost and the skip control below it, so read the displayed price before you choose Build or Skip.

Building hull blocks costs Energy at first and Plasteel later in the game, which is one more reason the early and late game want different amounts of weight and power — see the ship weight and fuel guide.

Attach it anywhere, or stand it on stilts

You can attach a block to any side of the hull, or place it a short distance away from the hull, in which case it stands on stilts and creates a corridor that aliens can walk through.

That second option is the interesting one. A block set out from the hull becomes an extra lane with a long approach, which is how you turn a straight sprint into the Airlock into a shooting gallery — see the turret placement guide for how to weaponize the extra corridor.

Module slots inside a new block

Module slots inside a new block are not automatically usable. In the demo, an empty module slot became available for construction only once a completed module sat next to it, and a neighbour that was still being built did not count.

In the full game that adjacency rule was removed: modules can now be built in any empty module slot, because the old rule confused a lot of players. Empty hull blocks still keep different visual designs, but those designs no longer affect where modules can be built. The changes since the demo guide lists that and the other launch-build differences.

What to check before you commit a block

There is no rotation and no removal, so spend a moment before you press Build:

  • Whether the Airlock and the Engine stay accessible.
  • Whether the shape and orientation suit your kits, since the shape limits which modules fit.
  • Whether the module kits you already hold, or are aiming for, fit the new cells.
  • Whether the route the enemies will take afterwards is one you want.

That last check is the one players skip and then regret. The boss strategy guide covers why route length is the single most valuable property on the hull.

Two layouts worth copying

The developers showed two shapes they liked: a compact arrangement where more modules are adjacent to one another, so artifact adjacency mechanics work better and crew have less distance to travel; and a layout that creates a longer route for enemies with more interesting firing positions.

Players also found an unintended strategy — building a spiral just outside the Airlock to create a maze for enemies approaching from above and below. The workforce guide explains why compactness matters beyond adjacency: every step your crew walks is a step they are not walking.