Nuclear Design Bureau — How to Save Designs and Game Progress

Nuclear Design Bureau how to save splits into two separate habits, and confusing them is why players lose work. Your campaign progress uses a normal save system with an anytime-save category and Steam Cloud, so the game covers the run for you. Your designs do not work that way: blueprints live in a design files feature that you have to use deliberately, and a reported symptom from the Steam discussions is a player losing every sandbox design between sessions because they expected the build to persist on its own.

How to Save and Load a Design

The design save path is not obvious, which is why the question keeps coming up. A community answer on the Steam discussions describes where to find it: there is a box to save your designs at the bottom of the materials menu, under the header design files, and saved designs can be loaded again from the drop-down menu at the top of the screen.

Action	Where it lives
Save a design	The save box at the bottom of the materials menu, under the header design files
Load a design	The drop-down menu at the top of the screen
Automatic design persistence	Not reported; designs are not kept between sessions by default
Reported symptom	Sandbox designs missing after exit and reload, requiring a rebuild

• Save after each meaningful iteration rather than only when a design works, because the failures teach you more.
• Name or order saves so a messy experiment does not overwrite the design you were improving.
• Save before a physics-heavy test, since large designs are slow to run and expensive to rebuild.
• Use the load drop-down to compare two layouts without rebuilding the first one.
• Treat the design files box as your scratchpad for a directive, and keep the working version separate.

Saving Progress, Cloud and Rollback

Progress saving is the well-covered side. Steam lists Save Anytime as an accessibility category, alongside Custom Volume Controls, Mouse Only Option and Playable without Timed Input, and the developer describes the current Early Access build as including save and load systems with ongoing stability improvements. Steam Cloud is also listed, so saves can travel with your account, and Family Sharing is supported.

Save feature	Documented status
Save Anytime	Listed as an accessibility category on the store page
Save and load systems	Present in the current build, with ongoing stability improvements
Steam Cloud	Listed among store features
Family Sharing	Listed among store features
Previous build branch	A hotfix note says the previous build is on a previous branch on Steam

The rollback branch is the detail worth remembering. A later hotfix note states that the previous build is available on a previous branch on Steam, which gives you a way to keep playing a working version while a new build settles. During Early Access that is a practical safety net rather than a curiosity, especially because the store page warns the build may contain bugs, freezes and crashes.

Reported Save Problems and What to Do

Two distinct issues appear in the recorded material, and they have different fixes. The sandbox design loss is a usage issue: the game has a save path, and the answer is to use it. The second is build-level instability, which the developer acknowledges and addresses through patches.

• If designs vanish between sessions, go to the design files box under the materials menu and save explicitly before exiting.
• If a new build misbehaves, check whether the previous build is available on the previous branch.
• If a save behaves oddly after a physics patch, read the patch note first, because the notes have announced changes to simulation behaviour that affect designs.
• Report repeatable issues on the hub rather than assuming a workaround is universal, because the developer states the campaign, physics and tools change based on player feedback.

One caution about guides: no official source publishes a save file location, a slot count or a cloud-sync troubleshooting procedure, so any page claiming those specifics should be marked to confirm. What is documented is enough to protect your work: save designs through the design files box, keep Save Anytime and Steam Cloud in mind for progress, and use the previous branch if a patch goes wrong. For what a saved design is worth once you reload it, see the guide page and the implosion page.