
Structure Extender
This mod adds a block that can be used in structures to extend things like chains up or down until they hit a block. It is used for structure mods.
⬇ Download on ModrinthThis mod adds the structure extender block, which can be used by mod creators to make structure making easier.
Video tutorial here:
What it does:
The structure extender block will detect if there is a block below or above it. If the opposite side is free, it will extend the detected block up/down until it reaches the next block.
So for example you have a mineshaft like structure and you want the chains to go up until they reach the cave roof, you can place the structure extender on top, and on loading it will automaticall extend the chains up.
How it works:
To build with the block, you first have to do "/gamerule structureextenderactive false" so that you can build with it without it activating instanly. You can then place it ontop of a block, and if there is at least one block of air, and at maximum 300 blocks of air above, it will extend the block from below upwards until it hits a roof. It will also replace itself in the process. The same works with having a block ontop of it and air below. When your structure loads into a new world, the structure extender block will automatically activate and do its thing
The block only works if there is either one block below it or one block above it. It can not have one block below and above at the same time. It can also not have just air below and above it.
It should be able to extend all blocks.
If you find problems:
If you find any problems, please contact us. The most effective way is to tell us in our discord server, as we will see it fastest there.
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.20.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as structureextendermod-1.0-1.20.1.jar — drop this file into the mods folder
- Download size: 18 KB
- Download link checked 4 Sept 2026 — working
These come from our own check of the pack file, not from the source page.