Subnautica 2 Advanced Base Building: Optimal Layouts & Design Tips

You’ve got a basic dome with a Fabricator and some storage lockers. It works. But “works” isn’t the same as “works well.” Once you understand the sculptural extrusion system and how power, oxygen, and space interact, you can build bases that are genuinely efficient and not just functional blobs.

This guide assumes you’ve already built your first base. If not, check our first base guide before continuing.

Understanding Sculptural Extrusion

The building system in Subnautica 2 threw out the grid entirely. Instead of snapping pre-made rooms together, you shape your base with a push/pull brush. Think of it like digital clay. Point at a surface, push it inward or pull it outward, and the base shape changes organically.

This sounds freeform and messy. It can be. But there are rules underneath the freedom.

How It Actually Works

Pulling from the seafloor creates upward extrusions — walls, pillars, domes
Pushing into terrain lets you embed your base into rock faces and coral formations
Connecting extrusions creates corridors and multi-room structures
The brush size matters — smaller brush for detail work and doors, larger brush for main rooms
Sealed spaces generate oxygen — if there’s an enclosed volume with power, it fills with breathable air

Common Shapes Worth Mastering

The Dome: Pull upward from a flat area. This is your basic room. Domes give you the most interior volume for the least surface area, meaning fewer structural integrity concerns.

The Corridor: Pull horizontally from a wall. Keep the brush narrow. Corridors connect rooms and give your base flow and direction. Without them, you end up with one big amorphous blob.

The Terrace: Pull outward from a wall at an upward angle. This creates elevated platforms inside your base — perfect for observation decks or placing equipment at different heights.

The Pocket: Push into a cliff face to create a cave-like room embedded in terrain. These look fantastic, save materials on exterior walls, and feel more protected.

Power Grid Design

Power is the backbone of everything. Oxygen, fabrication, lighting — all of it draws from your power supply. A well-designed power grid means you never see the “Oxygen Production Offline” message.

Layered Power Strategy

Don’t rely on a single power source. Layer them:

Primary: Hydroelectric Turbine (12 E/sec) — Place in the nearest water current. This handles your baseline power needs around the clock
Secondary: Solar Panel (1-8 E/sec) — Supplement during daylight hours, especially if your base grows beyond what one turbine covers
Backup: Bioreactor (variable) — Place inside your base, feed it organic material. This kicks in when primary sources dip

Power Transmitter Chains

Hydroelectric Turbines have to sit in currents, which might be 20-50 meters from your base. Power Transmitters relay energy between the source and your habitat. Place them in a line with no more than 15-20 meters between each one. Too far apart and the chain breaks.

Pro tip: Run your transmitter chain underground or along the seafloor to keep the exterior clean. Nobody wants a skyline of power poles outside their underwater home.

Thermal Plant Placement

For mid-to-late game bases near heat sources, the Thermal Plant generates 16 energy per second. That’s the highest output of any power source. If you’re building near volcanic vents or thermal fissures, this is your primary. One Thermal Plant can power a large, multi-room base alone.

Room Specialization

Resist the urge to put everything in one room. Specialized rooms make your base easier to navigate and more efficient to use.

Fabrication Room

Your main crafting space. Include:

Fabricator (obviously)
Modification Station (once unlocked)
2-3 storage lockers for raw materials
Wall-mounted resource display (if available)

Keep this room near the entrance. You’ll visit it constantly, and short travel distances add up over hours of play.

Storage Bay

A dedicated room for bulk storage. Line the walls with lockers and label everything. Separate by category:

Metals (Titanium, Copper, Silver, Lead, Gold)
Organic (plants, seeds, food)
Electronics (Wiring Kits, Computer Chips, batteries)
Gear (spare tools, tank upgrades, suit modules)

Keep the storage bay adjacent to the fabrication room. Grabbing materials and walking three steps to the Fabricator is the workflow you want.

Observation Room

Not just decoration. An observation dome or window room at the top of your base lets you check exterior conditions — time of day, fauna movement, approaching storms — without stepping outside. Place it high, make it transparent.

Vehicle Bay

If you’ve unlocked the Tadpole, you need somewhere to dock it. Build a moonpool or garage-style opening at your base’s lowest point. Water should flow into this room. The Tadpole parks here, charges from your power grid, and you can swap modules without going outside.

Structural Integrity

Large bases with many rooms can develop structural integrity issues. The game doesn’t let your base collapse instantly, but low integrity means leaks. Leaks mean flooding. Flooding means you lose oxygen in affected rooms.

How to Maintain Integrity

Reinforcement panels applied to walls boost integrity
Smaller, connected rooms are stronger than one massive open space
Foundation anchors at the base of your structure help with stability
Terrain integration — bases pushed into rock faces gain natural support

If you see water dripping through walls, your integrity is dropping. Apply reinforcements to the weakest sections before the leak becomes a flood.

Multi-Floor Designs

Vertical building opens up a lot of space in a small footprint. Here’s a layout that works well:

Ground Floor (Water Level)

Vehicle bay with moonpool
Storage room
Entry hatch

Second Floor

Fabrication room and modification station
Main corridor connecting to other rooms

Third Floor (Highest Point)

Observation dome
Solar panels on the exterior roof
Living space

Use vertical extrusions (pulling the ceiling upward) to create floor-to-floor transitions. Add ladders or ramps between levels.

Co-op Base Building

Building with friends changes the calculus. Four players means four times the oxygen draw and four times the storage needs.

Shared Base Tips

One shared power grid — Pool resources for a Hydroelectric Turbine + Thermal Plant combo
Personal storage sections — Assign each player 2-3 labeled lockers in the storage bay
Multiple Fabricators — Waiting in line to craft is a real problem with four players
Wider corridors — Two-player-wide corridors prevent traffic jams
Separate vehicle bays — If multiple players have Tadpoles, you need docking space for each

Task Division

In co-op, specialize during construction:

One player handles power infrastructure
One player builds the main structure
One player gathers materials
One player scouts the perimeter for threats

This is faster than four people independently pulling at the same wall.

Design Principles That Actually Matter

Function first, form second. A base that looks like a coral palace but has the Fabricator 40 meters from storage is a bad base. Optimize for workflow, then make it pretty.

Build from the inside out. Decide what rooms you need and how they connect before you start shaping exterior walls. Interior layout determines exterior shape, not the other way around.

Leave room to expand. Don’t seal off every side of your base. Keep at least one wall or corridor open-ended for future growth. You will want to add rooms later. Make it easy.

Test your oxygen before going big. After building each new room, stand inside and check the oxygen indicator. If it’s dropping, you need more power before you add more space.

The extrusion system rewards experimentation. Your tenth base will look nothing like your first. That’s the point. Keep building, keep refining, and don’t be afraid to bulldoze something that isn’t working.