Base Building
Base building in Subnautica 2 has received a major overhaul, described by the development team as "Underwater Base Building 2.0." The developers stated they are "making base building better with more customization than ever before" with "shapes and ways they've always wanted." Dev Vlog 1 (April 23, 2025) showed the updated system in action, and Design Lead Anthony Gallegos framed it as a central pillar of the Early Access offering. The team noted: "We've taken everything that we've learned from our experience on the previous games, and we've poured it into Subnautica 2."
How the new system works
The original Subnautica used a rigid grid-based building system. Players snapped corridors, multipurpose rooms, and observatories together at fixed attachment points aligned to cardinal directions. The result was functional but visually uniform: most player bases looked like variations of the same tube-and-room structure. Below Zero added the Large Room and Control Room but kept the underlying system largely the same.
Subnautica 2 reworks this system with three key changes:
Change | Description |
|---|---|
More connection points | Each building piece has significantly more attachment spots than in previous games, allowing greater variety in how structures connect. |
Greater placement freedom | Builders face fewer restrictions on where individual pieces can be positioned relative to one another. The rigid cardinal-direction-only attachment system has been loosened. |
More building pieces | The total number of buildable components is larger, with some pieces designed for specific aesthetic or structural roles. |
The system has been described as enabling players to "snap pressure chambers together like sci-fi Lego." While it retains a modular snap-point attachment logic (pieces lock to other pieces at defined points), the expanded connection options mean bases can have significantly more complex and distinctive layouts than was possible in previous games.
New structural elements
Dev Vlog 1 footage revealed several new construction components:
Piece | Description |
|---|---|
Support pillars | Structural columns that reinforce bases and create more architecturally varied constructions. Enable vertical complexity not possible in previous games. |
Superconducting foundations | A new foundation type, likely related to power distribution throughout larger bases. |
Half-Round Room | A named new room type shown in development footage. Not present in previous Subnautica games. |
Nook | A smaller, specialized compartment shown in development footage. Suggests more granular room sizing beyond the binary corridor/multipurpose room options of the original game. |
Dev Vlog 1 also showed bases with noticeably more complex silhouettes and ornate layouts than were possible in the original game, suggesting additional piece types beyond those specifically named above.
Power management
Bases on Planet Zezura require constant power to maintain life support systems including oxygen supply. The specific power generation types available on Zezura (solar panels, thermal plants, bioreactors, nuclear reactors, or new alternatives) have not been officially confirmed. The original Subnautica offered all four of those options, but whether they return unchanged, are modified, or are supplemented by new power sources tied to Zezura's environment has not been announced.
The presence of "superconducting foundations" as a named building piece suggests that power distribution within a base may be more mechanically involved than in previous games, potentially affecting how efficiently power reaches distant modules.
Co-op base building
In multiplayer sessions (up to four players), bases are shared between all players. Several co-op-specific mechanics have been confirmed:
Feature | Details |
|---|---|
Shared power management. | Power is pooled across the base. Life support must stay active for all four divers simultaneously. If the base runs out of power, everyone suffers. This creates natural coordination around resource gathering and power infrastructure. |
Individual oxygen. | While power is shared, oxygen management remains individual to each player. |
Shared blueprints. | Blueprints are bound to the save file. New blueprints discovered by any player become available to the entire team. This means a group can divide exploration duties to unlock recipes faster. |
Simultaneous building. | Players can build independently within the same world at the same time. One player can gather resources while another expands the base. |
Save conversion. | A single-player save can be converted to a multiplayer session, allowing players to invite friends to see and expand an existing base. |
Resource changes
Dev Vlog 1 showed a completely reworked resource system that directly affects base building. Resources on Zezura use resource-specific nodes on the seafloor that can be identified visually and collected by hand. This replaces the breakable limestone, sandstone, and shale outcrops from previous games that dropped randomized materials. Players can now target the exact resources they need for construction rather than relying on chance drops.
Resources are stored as fractional quantities using a decimal-based inventory system (for example, "0.71 titanium" rather than whole units). This granular tracking changes how players plan material gathering for base construction, since building pieces may require precise fractional amounts rather than whole-number stacks.
What remains unknown
As of March 2026, the following base building details have not been officially disclosed:
Whether a Moonpool or dedicated vehicle docking module exists for the Tadpole
Specific power generation types available on Zezura
Whether hull integrity returns as a mechanic (bases flooding when structural integrity drops)
How base building interacts with Blight-affected zones
Interior decoration and furniture options
Crafting costs for specific building pieces