A Blueprint Designer saves whatever you build inside its boundary box, and placing that blueprint later costs exactly what the pieces would cost built by hand — no extra tax, but extractors and a few late-game buildings never fit.
A Blueprint Designer is a room-sized boundary box: build inside it, walk up to the Control Bench built into its base, name what you made, and it becomes a reusable template. Placing that blueprint later costs exactly the sum of what each building inside it costs on its own — there's no extra fee for the blueprint itself, just the normal materials pulled from your inventory as it snaps into place.
The Blueprint Designer comes in three marks, unlocked at three separate milestones, and each one is physically bigger than the last:
| Designer | Unlocks at | Interior | Exterior footprint |
|---|---|---|---|
| Mk.1 | Tier 4 — FICSIT Blueprints | 32×32×32 m | 40×40 m |
| Mk.2 | Tier 6 — FICSIT Blueprints Mk.2 | 40×40×40 m | 48×48 m |
| Mk.3 | Tier 9 — FICSIT Blueprints Mk.3 | 48×48×48 m | 56×56 m |
Mk.2 and Mk.3 were added in the 1.0 update — before that, there was only one designer size, and the current Mk.1 is that original design carried forward under a new name. A blueprint is tied to the mark it was designed in: something built in a Mk.3 designer needs a Mk.3 (or better) designer to edit, though a Mk.1 blueprint can be dropped into a bigger designer without issue.
Inside the boundary you place buildings the same way you would anywhere else — constructors, belts, pipes, foundations, walkways, power poles — as long as every piece sits fully inside the frame (pillars are the one exception; they're allowed to poke through the edge). Loaded storage containers and machines with fuel or ingredients already sitting in their input buffer save that inventory too, so a blueprinted smelter with ore in the hopper starts working the moment it's placed, not empty.
When you're done, the Control Bench asks for a name, a description, a category and sub-category for the build menu, an icon, and a background color. None of that is cosmetic filler you can skip — it's how you find the right blueprint again once you've built forty of them.
A short list of things the designer refuses outright, on every mark:
A second tier of buildings — Nuclear Power Plants, Particle Accelerators, Alien Power Augmenters, Train Stations, and freight platforms — only fit starting at Mk.2, simply because Mk.1's 32-meter box is too small for them. None of this touches ordinary belts, pipes, or power lines: those go in freely, and when you place the finished blueprint, its loose belt and pipe ends will auto-connect to anything already built up to 16 meters (two foundations) away, instead of needing you to snap every joint by hand.
Every blueprint is actually two files: an .sbp with the layout itself, and an .sbpcfg with the name, description, icon, and color you set at the bench. On Windows they land in %LOCALAPPDATA%\FactoryGame\Saved\SaveGames\blueprints\{your session name} — a folder that sits outside the regular save-game directory and, critically, isn't part of Steam Cloud sync the way your save file is. Losing that folder means losing every blueprint you've built, save-independent, so it's worth backing up on its own.
Sharing one is just copying the .sbp file — the .sbpcfg is optional, since without it the blueprint imports with blank metadata instead of your original name and icon. Drop a shared file into the matching session's blueprints folder and reload the save before it shows up in your own build menu; it won't appear in a session that's already running.
The blueprints that pay off fastest aren't the biggest ones — they're the ones you'd otherwise place by hand fifty times over. A single foundation tile with the floor pattern, lights, and walkway lip you've settled on is worth blueprinting before anything else, since it's the piece every base is made of. After that, a standard conveyor belt-and-pole run at a fixed height saves the repetitive alignment work that eats time on every new production line, and a single manifold segment — one splitter tap feeding one machine, built the way manifolds actually work — turns into a copy-paste module the moment you need a sixth or seventh machine on the same belt. None of the three needs a Mk.2 or Mk.3 designer; all three fit in the base Mk.1 box, which is exactly why they're the ones to build first. Once those habits are in place, scaling up to whole recipes worth of production line is a placement problem, not a building one.