Multipurpose Room (Subnautica)

The Multipurpose Room is a Seabase Module. It is a large drum-shaped module with an octagonal interior, which by default is empty. It provides a much larger space for movement and placement of internal fixtures than the I Compartment and its variants, and is the only module where several of the larger internal fixtures can be placed.

It is constructed with a Habitat Builder and can be placed on top of a Foundation or on its own, forming legs if it is close enough to terrain in the latter case. When the Multipurpose Room is horizontally adjacent to another Seabase module, a small length of corridor is automatically created to join them. When the Multipurpose Room is "stacked" with another Multipurpose Room, the floors can be accessed by building ladders, or by constructing an Alien Containment with hatches on the levels the player wishes to be able to access.

Every Multipurpose Room added to a Seabase reduces the Hull Integrity by 1.25 (The game shows -1.3 because it rounds the number. It is functionally -1.25). The first piece of a Seabase starts with +10 Integrity, thus if a Multipurpose Room is the first piece built it gets 10 - 1.25, or 8.8 (rounded) at surface depth.

Expansion

 * I Compartments, T Compartments and X Compartments can be placed on the side-panels in the four cardinal directions, but not the ordinals. Other base modules that auto-generate connections follow the same rule.
 * Hatches can be placed on all eight of the side-panels. In addition, if the Room contains an Alien Containment, Hatches can be built inside the Room on the exterior of the Alien Containment in the four cardinal directions to provide access.
 * Windows can be placed on all eight of the side-panels.
 * Ladders can be placed in five specific spots, four forming a square around the perimeter of the room in the cardinal directions and one in the center, as long as there is a Multipurpose Room above or below to connect to. The locations forming a square will preclude building a Water Filtration Machine at that location in both rooms the ladder connects, while the center location will prevent construction of an Alien Containment, Bioreactor or Nuclear Reactor in both rooms. If ladders are built in the same location on multiple floors, they will still be scaled one floor at a time. Note that the module cannot be deconstructed if it still contains any ladders.
 * Reinforcements can be placed on all eight of the side-panels for Hull Integrity bonus.
 * An Alien Containment, Bioreactor or Nuclear Reactor can be placed in the center, and Water Filtration Machines can be placed on all eight of the side-panels. This is the only placement option for these four modules.
 * A Multipurpose Room can be expanded vertically using a second Multipurpose Room. Once this is done, the Multipurpose Room on the bottom will lose its rounded top to connect to the Multipurpose Room above it.
 * Alien Containments stacked in multiple vertical Multipurpose Rooms will join together into a single floor-spanning unit. Placing an Alien Containment will also turn the middle of the floor of a room above into a circular glass panel: this does not affect the ability to place modules on the central spot in that room.
 * Vertical Connectors cannot be used on a Multipurpose Room.
 * Bulkheads cannot be placed in the automatically generated corridor sections or directly at the doorways.

Recipe
The Multipurpose Room blueprint can be acquired by scanning a Multipurpose Room at any of the Degasi Seabases.

Trivia

 * Concept art for the Multipurpose Room showed it with optional glass ceiling and floor pieces: neither was realized in Subnautica. The option to build a glass ceiling is present in Below Zero.
 * With the Living Large update, the glass ceiling has been back-ported from Below Zero to the original game.
 * The Multipurpose Room was originally called Room.

Salle multifonction