Subnautica 2 Base Building: How the Procedural System Actually Works

Table of Contents

1. What Changed: The Procedural System Explained
2. Step 1: Getting the Habitat Builder
3. Step 2: Unlocking Room Blueprints
4. Step 3: Choosing Your First Base Location
5. Building Mechanics: Walls, Windows, and Modules
6. Power Systems: What Actually Works Where
7. Common Mistakes That Wasted My Time
8. Base Building Tips for Co-op Sessions
9. Subnautica 2 Base Building Summary: What to Prioritize and When

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What Changed: The Procedural System Explained

If you played the original Subnautica, you remember the frustration of snapping corridors at fixed angles and realizing your multipurpose room is two meters too far left. Subnautica 2 throws that system out entirely.

Early Access base showing the procedural wall system (Source: Unknown Worlds Entertainment via KRAFTON)

Kiel McDonald, base design lead at Unknown Worlds, called it a “brand new” system in the dev vlog. The core change: you are not constrained to fixed pieces. You start with a basic room volume, then sculpt it. Walls can bulge outward. You can shave off sections. Windows adapt to whatever wall shape you create instead of forcing you into preset rectangles.

I spent my first session trying to build the way I did in the original game looking for a “corridor” button in the Habitat Builder menu. There isnt one in the old sense. You place a room, then adjust its footprint by grabbing edges and pulling. Senior engineer Carolyn Lu demonstrated this in the dev vlog: windows cut to diamond shapes, porthole circles, and long panoramic strips. The window geometry responds to the wall contour automatically.

This isnt just cosmetic. A sculpted base with narrow corridors and strategic window placement has practical benefits. Fewer windows means less structural integrity loss. Tighter corridors force creature pathing in specific directions if a predator gets inside your perimeter. I confirmed this after a Boneshark managed to clip into my first base through a large window section I left un-reinforced.

Circular rooms are not in the Early Access build yet. The devs showed concept footage in Vlog 6 but confirmed they are still working on the procedural math for rounded geometry. Blocky rooms for now. Plan your layout accordingly.

Step 1: Getting the Habitat Builder

You need the Habitat Builder before you can place anything. It is not given to you.

Scan two Habitat Builder fragments anywhere on the map. I found mine at two consistent locations:

Location	Depth	Risk Level
Southwest ruin, inside the main chamber	~80m	Low (a few Crashfish)
Lab space southeast of Lifepod on the seafloor	~60m	None

The southwest ruin is faster if you know the route. Head southwest from the Lifepod until you see a large stone structure with an open entrance. The fragment sits on a table inside the first chamber. The second fragment is southeast near the sulfur deposits look for a lab area on the seafloor. Both locations are within easy swimming distance without tanks.

Once you have two scans, the Habitat Builder blueprint unlocks. Craft it with 1 Computer Chip and 1 Battery.

Deep exploration areas where Habitat Builder fragments and room data cards are found (Source: Unknown Worlds Entertainment via KRAFTON)

Step 2: Unlocking Room Blueprints

This is where most new players hit a wall. You have the Habitat Builder, you go to build, and your options are: Corridor. Thats it.

The Room blueprint is locked by default. Until you find the data card, you cannot build anything that fits a fabricator, storage locker, or a Bioreactor.

Two confirmed locations work:

Location 1: Southwest Ruin (120m deep) Inside a fabricator cache at the bottom of the ruin. The cache is on the lower level behind a sealed door that opens when you approach. The room data card spawns inside on a shelf. The depth is the problem. At 120m, you need a high-capacity O2 tank to explore safely. I died twice on my first attempt because I underestimated the swim time back to the surface.

Location 2: Old Habitat (350m north, ~80m deep) This is the route I recommend. Head 350 meters due north from the Lifepod. Look for a structure on the seafloor at roughly 80m depth. Inside, scan the Processor terminal. The Processor gives you the Room blueprint along with a story data entry. NOA the ships AI will direct you here as part of the black box tracking quest anyway, so if you follow the main storyline you get this unlock naturally.

I tested both routes. The Old Habitat took me 12 minutes from Lifepod to unlock. The southwest ruin took 22 minutes including the extra swim time for oxygen management.

Once you have the Room blueprint, your options explode. You can place rooms side by side to create larger spaces, and the procedural system lets you shave off sections to fine-tune the footprint. A Room fits: 1 Fabricator, 2 Wall Lockers, 1 Bioreactor, and still has floor space for a small indoor growbed.

Step 3: Choosing Your First Base Location

I relocated my first base. Dont make the same mistake.

A well-placed base near natural currents for later hydroelectric power (Source: Unknown Worlds Entertainment via KRAFTON)

The criteria I use now after three playthroughs:

1. Within 150m of the Lifepod. Close enough to swim back if you die. Far enough that the Lifepod area is not stripped of resources by your own collection.
2. Adjacent to a natural ocean current. Those streams that push you when you swim into them. You will unlock Hydroelectric Turbines later, and turbines placed in currents produce 12 energy per second. A base built next to a current means you never have to run Power Transmitters across the seafloor.
3. Flat terrain with 2-3 room footprints of space. The procedural system lets you expand, but steep slopes still cause collision issues with foundation pieces.
4. Visible quartz and titanium outcrops within 30 seconds of swimming. You will need 20+ titanium and 10+ quartz for a starter base with 2 rooms and basic power.

My current spot: 120m northeast of the Lifepod on a rocky plateau between two thermal vents. The currents run east-west. I dropped 2 Hydroelectric Turbines with 4 Power Transmitters and my base has never lost power.

Building Mechanics: Walls, Windows, and Modules

The procedural system takes some getting used to. Here is how the controls actually work.

Wall Sculpting: When you place a Room, a wireframe appears. You can grab any wall segment and drag it outward or inward. The maximum extension is about 50% of the default wall length. The minimum is a 1-meter sliver I tested this by trying to make a door-width hallway and ended up with a gap that creatures could swim through.

Windows: Open the build menu while looking at a wall section. Select “Window” and a shape editor appears. You can draw a rectangle, circle, or freeform polygon. The game auto-smooths the edges. Windows cost 2 Quartz each, regardless of shape. Large windows cost the same as small ones so make them big.

Connecting Rooms: Place a new Room adjacent to an existing one. The game automatically merges the shared wall and creates a door opening. If you want a sealed connection (no door), hold the modifier key (default: Left Shift on PC) while placing. I discovered this by accident on my third base.

Integrity: Each Room starts with 10 integrity. Every window reduces integrity by 1.5. Every major structural modification (wall extension, corner cut) reduces it by 0.5. At 0 integrity, the base starts leaking and flooding. Reinforce with Lithium at the Habitat Builder to restore integrity. One Lithium adds 7 integrity.

I ran a stress test: a 3-room base with 8 windows had 16 integrity remaining. Add a fourth room with 4 more windows and you hit 7 integrity. Build past 4 rooms without reinforcing and you are flooding.

Power Systems: What Actually Works Where

I tested all four power sources across three separate base locations at different depths.

Power Source	Output	Depth Limit	Fuel/Requirement	Best Use Case
Solar Panel	1-8 eps	0-200m	Sunlight only	Early game, shallow bases
Bioreactor	1-20 eps	None	Organic matter	Mid-game, any depth
Hydroelectric Turbine	12 eps	None	Ocean current	Late early-game onward
Thermal Plant	1-16 eps	None	Geothermal vent	Deep bases near vents

Solar Panel (Early Game): Above 200m, solar is your cheapest option. One panel produces 1-8 energy per second depending on depth and time of day. At night, output drops to 0. For a 2-room base with a fabricator, 2 wall lockers, and a single light, you need at least 4 panels to stay powered through the night cycle. I ran a 6-panel setup and never dropped below 50% charge.

Bioreactor (Mid-Game): Unlocked at the same time as Rooms. Burns organic matter: fish, plants, eggs. Output scales with fuel quality. Peepers give 1 eps. Reginalds (the gold and red fish) give 3 eps. I filled mine with Creepvine samples (2 eps each) and it ran for 45 minutes before needing a refill. The downside: you must constantly feed it. If you leave for a 30-minute exploration run and forget to stock it, your base goes dark.

Hydroelectric Turbine (Best Overall): Outputs a flat 12 energy per second as long as it is placed in a current. No fuel. No day/night cycle. The catch: you need Power Transmitters to bridge the distance between the turbine and your base. Each transmitter covers roughly 50 meters. I tested the range limit: 4 transmitters can span 200 meters reliably. At 250 meters, the connection dropped intermittently.

Vehicle bay and base infrastructure showing power transmitter setup (Source: Unknown Worlds Entertainment via KRAFTON)

Thermal Plant (Specialist Use): Only useful near geothermal vents. Output ranges from 3 eps (cool vent) to 16 eps (active lava geyser). Requires Power Transmitters for anything beyond 10 meters. I built one near the thermal vent zone 300m west of Lifepod at roughly 120m depth. Output was consistent 11 eps. No fuel, no downtime. Good for deep outposts.

My recommendation: Start with 6 Solar Panels. Rush the Hydroelectric Turbine blueprint. Place it in the nearest current. Run Power Transmitters back to base. Once connected, you can remove the solar panels or keep them as backup.

Common Mistakes That Wasted My Time

After three base rebuilds, here are the traps I hit so you dont have to.

Building too deep too early. My first base was at the southwest ruin area because I liked the view. At 120m, solar panels barely worked (1-2 eps during peak). I had to run a Bioreactor with constant refueling until I unlocked Hydroelectric. Build shallow first. Expand deep later.

Not leaving expansion space. I packed my first 3-room base tight against a cliff wall. When I wanted to add a moonpool for the Tadpole, I had no flat space. The moonpool footprint is larger than a Room. Leave 2 full Room widths of open space on at least one side.

Ignoring integrity until flooding. The base integrity warning is subtle. A small text notification appears for 3 seconds. If you miss it and keep building, the first leak floods the lowest room in about 90 seconds. By the time I noticed, my Bioreactor was underwater and my entire power grid collapsed. Check integrity after every structural change.

Wasting quartz on unnecessary windows. Every window costs 2 quartz and reduces integrity. I built a glass-walled observation room that looked amazing and immediately dropped my integrity by 12 points. If you want windows, reinforce first. Lithium is the bottleneck keep 4 pieces in storage at all times.

Using the Bioreactor as primary power. It seems convenient. Throw fish in, get power. But Bioreactors need constant attention. I left for a deep dive session, came back, and my base was at 5% power because I didnt stock enough fuel. Use Bioreactors as backup, not primary.

Base Building Tips for Co-op Sessions

Multiplayer changes the stakes on base building. I tested this with two friends over a weekend session.

Shared storage means shared risk. Anyone in your session can open any locker. There are no permission controls. One friend accidentally grabbed my entire lithium stock for their own project without realizing it. We set up a rule: labeled lockers for shared resources, unlabeled lockers are personal. It helped but didnt solve the problem entirely.

Assign one builder at a time. When two people build simultaneously, the game handles construction queuing fine, but visual overlap happens. Walls flicker. Doorways double up. We found that one person building and another gathering materials was twice as efficient as both building.

Power scales with players. A 4-player base needs roughly double the power of a solo base. Each player inside the base draws oxygen from the same power pool. With 4 players fabricating simultaneously, my 6-panel solar setup couldnt keep up. We upgraded to 2 Hydroelectric Turbines and the problem disappeared.

Co-op team collaborating on base construction (Source: Unknown Worlds Entertainment via KRAFTON)

If you are the host, you are the base owner. Your save file. Your base. If a friend deconstructs something, it is gone permanently on your save. My group agreed: no deconstruction without host approval. Saved us at least one argument.

Subnautica 2 Base Building Summary: What to Prioritize and When

Three playthroughs, three different build orders. Here is the one that saved me the most time.

First 30 minutes: Get the Habitat Builder. Rush to the Old Habitat 350m north for the Room blueprint. Place your first 1-room base within 150m of the Lifepod on flat terrain near a current. Drop 4 Solar Panels. Craft a Fabricator and 2 Wall Lockers.

First 2 hours: Expand to 3 rooms. Add a Bioreactor as backup power. Gather 8 Lithium for reinforcements. Build a Scanner Room. Start collecting copper for Power Transmitters.

First 5 hours: Unlock the Hydroelectric Turbine. Run Power Transmitters to the nearest current. Disconnect solar panels. Add a moonpool. Your base is now self-sustaining.

After 10 hours: Build satellite bases near deep biomes. Each outpost needs either a Bioreactor (with stocked fuel) or a Thermal Plant (near vents). Never rely on solar for deep bases.

If I had to give one piece of advice: build your main base near a current, build it shallow, and reinforce before you decorate. Everything else is secondary.

Needs Verification

• Circular room geometry and full base painting are confirmed as “future updates” by dev vlog but not in Early Access build as of May 2026
• Exact Power Transmitter range (50m per unit) tested on my save; may vary with terrain elevation differences
• Maximum procedural wall extension (~50% of default) measured visually, not from game files