Rust does not explain its building system. Most players learn these rules by getting raided through a soft side or watching their base decay overnight. This covers what matters before you start building big.

Build Zones

When you place a TC it creates a no build zone. The zone is based on the foundations attached to the same foundation your TC is placed on. The more you build out from that foundation, the larger the zone becomes. Players not authorised on your TC cannot build, upgrade, or place deployables within it.

This stops neighbours encroaching and stops raiders placing twig foundations mid-raid to build towers against your walls. External TCs on separate foundations extend your claimed area beyond the main base.

Monuments have their own permanent no-build zones that cannot be overridden. The radius varies by monument size. Check before choosing a build spot.

Building blocked prevents

Placing foundations
Upgrading pieces
Placing deployables
Picking up deployed items

Building blocked still allows

Placing twig
Placing ladders
Opening unlocked doors
Removing unlocked locks

Lock the TC immediately An unlocked TC can be authorised by anyone who walks up to it. They get full building privilege in your zone and can wipe your auth list. Code lock it the moment it goes down.

Decay

Every building piece slowly loses health once the TC runs out of resources. Different tiers decay at different rates. Stock the TC before logging off or the base will not survive a long offline session.

Time to full decay (TC empty)

Twig: 1 hour
Wood: 3 hours
Stone: 5 hours
Metal: 8 hours
Armoured: 12 hours

Upkeep resource by tier

Wood pieces: wood
Stone pieces: stone
Metal pieces: metal frags
Armoured pieces: HQM
Mixed base: all of the above

Open the TC and check the upkeep tab. It shows exactly how many resources are consumed per 24 hours and how long current stock will last. Upkeep scales with piece count: every foundation, wall, floor, door frame and ceiling adds to the daily cost. This is the main reason to keep early bases compact.

Use rusthelp.com to calculate exact upkeep for your base layout before you commit to building it.

Decay only starts after the TC empties Pieces take no damage while the TC has resources. The decay timer only begins when a resource runs completely dry. Stock it and the base is protected indefinitely.

Hard Side and Soft Side

Every wall has two faces. Both faces take the same damage from explosives and tools. The difference is the soft side is vulnerable to soft-siding: a raiding technique where players use specific tools to break open a wall from that face for a fraction of the normal raid cost. It is a form of eco raiding and the reason soft sides must always face inward.

Stone: hard side is smooth. Soft side has visible ridging. Sheet metal: hard side has the crossbars, soft side is the flat panel.

When in doubt, place a wall and walk outside to check which face is visible before upgrading. The soft side always faces whoever placed the wall.

Check before upgrading Use a hammer to rotate a misplaced wall at any tier. This does not destroy the piece at any grade. Fix every wall before the base is finished.

Door Placement

Door swing direction is determined by where the hinges are, not who placed the door. Hinges on the right mean the door swings outward. Hinges on the left mean it swings inward. When placing a door, look at which side the hinge icon appears and choose accordingly.

When a door is open it creates a gap on the hinge side. Someone standing on that side can shoot through the gap without you being able to close it on them. Think about which way each door swings and what it exposes when open.

Double doors: if the centre panel points slightly away from you, the door swings out. If it points slightly inward, it swings in. Check before placing.

Picking up a door You can pick up a door at any time. Unlock the lock, remove it, open the door, then hold E. There is no time limit. Door frames can be rotated with a hammer at any building tier.

Stability

Every building piece has a stability value. A foundation starts at 100%. Each piece placed on top of or extending outward from it loses a percentage. If a piece drops below the threshold it will not place. Aim your building plan at any piece to see its current value.

You can increase stability by reinforcing your structure. Adding wall frames, floors, and additional foundations raises the stability of pieces above and around them. Tall bases need a solid core. A thin stack loses stability quickly as you build upward.

Never leave a socket empty Every open socket in your base should have a wall, door frame, or wall frame in it. Occupied sockets maximise stability across the whole structure and leave no gaps for people to shoot or throw things through.
Stability does not affect raid damage A wall at 20% stability takes the same damage as one at 100%. Stability only controls whether a piece can be placed and whether it collapses if something beneath it is destroyed.

Honeycombing

Honeycombing gets its name from the cellular structure of a honeycomb. It means placing extra foundations and walls around the outside of your base so raiders have to blow through more walls to reach your loot. Without it, getting through your outer wall puts them directly inside. With it, there is another wall behind it.

Triangle foundations are the standard choice. They take up less space than squares for the same raid cost, are more versatile in how they fit around a base, and cost less stone. You place them around the outer walls of your base, add walls on the exposed faces, and leave no door frame. The inside of each honeycomb cell should be completely inaccessible.

Honeycombing increases the raid cost of going through your walls. It does add to your daily upkeep, so factor that in before building a full layer.

Do not honeycomb without a plan. Come up with a base design first and work out where honeycomb fits before you start placing. It is easy to end up with gaps or misaligned cells that defeat the point. Start with the TC room and the most exposed side. Expand from there.

No door frames in honeycomb A door frame in a honeycomb cell is a free entrance. Solid walls only.

Building Around Terrain

Terrain is part of your base. A large rock removes a potential raiding spot for free. A cliff removes an entire approach. Most experienced players factor terrain in before placing the first foundation. See the building spots guide for recommended locations on this server.

Building against a rock means raiders cannot access that face or build up against it to reach your roof. The tradeoff is you cannot expand in that direction, and terrain can trap you when being chased home.

Uneven ground can leave gaps underneath your base that someone can throw explosives through. Check the underside of your foundations before finishing. Fill any gaps with triangle foundations or walls.

Higher ground gives a longer sightline and forces attackers to approach uphill. It is also more visible from further away, so raiders will find it earlier in the wipe.

Monument no-build zones You cannot build within a set radius of monuments. The radius varies by monument. If your building plan shows red, move further out. Check your upkeep rate on rusthelp.com once the base is up.

What Not to Do

Twig left inside a finished base. Twig decays in an hour and costs nothing to destroy. Any twig frame or floor inside a stone base is a free entrance. Remove all twig before logging off.

Soft side facing out. One misplaced wall on your outer face can be soft-sided for a fraction of the normal raid cost. Walk the outside of your base and check every wall before logging off.

Building too close to a monument. The no-build radius is larger than it looks. Move further out than you think you need to.

Overbuilding upkeep. A large base costs more resources per day than most players can sustain early in a wipe. Build what you can stock, then expand once the resources are there.

No lock on the TC room door. A code lock costs 100 metal fragments. Anyone who gets inside your base without raiding through your walls can walk up to an unlocked TC and wipe your auth list.

Empty sockets in your walls. Every open socket is a stability gap and potentially a shooting angle. Fill every socket with a wall, door frame, or wall frame.