Build Helper

Build Helper is a client-side Minecraft mod focused on making large-scale building faster, safer, and less repetitive. It combines shape-based building modes, blueprint workflows, mining/construction templates, and environment helpers into one toolset.

What It Does

Build Helper helps you:

build repeated structures from a selected region
fill, hollow, frame, or shell large shapes
create standard tunnel and stair patterns quickly
save structures as blueprints
preview, rotate, mirror, and auto-build blueprints
place temporary support blocks for floating parts
clean up support blocks after building
reduce placement mistakes with auto-sneak interaction helpers
deal with lava and fire hazards while working

Main Features

Region-Based Building Modes

The mod can use a selected area and apply common construction patterns such as:

Fill
Box
Frame
Core
Pillar
SlabFloor
Spherical
SphericalShell
HorizontalRing
HorizontalRingShell
Clean

These are useful for walls, shells, solid fills, hollow shapes, and other repetitive building tasks.

Concretize Modes

The mod also includes template-style excavation / construction modes for infrastructure work:

upward and downward stairs
walled stairs
enclosed stairs
1x2, 1x3, 2x2, and 2x3 channels
2-high and 3-high fishbone mining layouts

These modes are useful when you want consistent tunnels, stairs, and mining patterns.

Blueprint System

The blueprint system is currently an experimental feature.

Please assume the following up front:

there are still many known and unknown issues
only a small number of block types have been tested
save errors, rotation errors, placement errors, facing errors, and configuration errors are all currently considered normal failure cases

So far, only a limited set of blocks has been tested with any confidence, including:

stone
glazed terracotta
trapdoors
slabs
stairs
redstone repeaters

If you want to use blueprints with complex blocks, containers, redstone components, or unusual block states, test in a separate world first.

The blueprint system lets you:

save a selected build as a .schem file
load and manage saved blueprints
preview blueprint placement in the world
move the blueprint position
rotate or mirror the blueprint
auto-build with materials from your inventory
place temporary supports for floating blocks
remove mismatched or extra blocks in the target area
clean support blocks when building is done

The default blueprint folder is config/buildhelper/blueprints.

Build Assistance

The mod also includes quality-of-life helpers:

automatic sneak interaction for blocks that require careful right-clicking
block facing controls
slab and stair placement preferences
optional use of the held material as a forced replacement source
mode history and quick switching tools

Hazard Helpers

Firefighter mode helps with fire-related situations
LavaHater helps manage nearby lava
temporary lava-source clearing can create a short working window in dangerous areas

Quick Start

1. Prepare a Selection Tool

By default, the mod expects an item named Build-Helper-Tool to be used as the selection tool. You can change this name in the config GUI.

2. Select a Region

Hold the selection tool in your main hand.
Its displayed item name must exactly match the configured tool name. By default this is Build-Helper-Tool.
The item must not be a placeable block item.
Sneak and right-click a block with your main hand.
The newest clicked position becomes the latest point, and the previous latest point is shifted into A/B history.

The mod will use this A/B region for many building modes.

Important details:

If a mode is currently running, selecting a region will stop it first.
The coordinates are shown in chat after each successful selection.
Internally, the previous latest point is moved into A, and the new click becomes B. In practice, this works like a rolling two-point selection.

3. Choose a Mode

Open the mode selector, pick the mode you want, confirm the region or direction settings, then start it.

Typical flow:

select a mode
confirm region, direction, or blueprint position
enable the mode
adjust placement with scroll controls if needed

Note:

Scroll-based shortcuts only work while you are holding the configured build tool name in either hand.
If you are not holding the correct tool, the scroll shortcuts do nothing.

Default Keybinds

Current built-in default keybinds in the codebase are:

H: enable / stop the current mode
J: open the mode selector
M: mirror the active blueprint
L: temporarily clear nearby lava sources

Some supported actions may currently be unbound by default, so you may want to assign them manually in Minecraft controls:

blueprint management
settings GUI
firefighter toggle
lava hater toggle

Scroll Wheel Controls

Scroll shortcuts only work when:

you are holding the configured build tool name
the current mode is a supported region mode, BlueprintBuild, or a concretize mode

`Alt + Scroll`

switch to the previous or next mode

`Shift + Scroll`

Moves the current target:

regular region modes: moves the whole A/B selection
BlueprintBuild: moves the blueprint placement position
concretize modes: moves the concretize origin

Movement rules:

if your pitch is above 45°, it becomes vertical movement
otherwise it moves forward/backward based on your facing direction
each scroll step moves by 1 block

`Ctrl + Scroll`

Adjusts range or depth:

regular region modes: expands or shrinks the boundary on the side you are looking at by 1 block
concretize modes: adjusts forward depth / region limit
this does not apply to normal blueprint placement movement

`Shift + Ctrl + Scroll`

Rotates the active target by 90°:

regular region modes: rotates the selected region
concretize modes: rotates concretize direction
BlueprintBuild: rotates the blueprint around the axis derived from your current view direction

Region Selection vs Mode Behavior

most basic building modes require an A/B region
BlueprintBuild uses blueprint placement coordinates instead of the normal A/B region as its main build target
concretize modes use their own origin and facing system
if a mode requires a region and A/B is not set, it will not run

Blueprint Workflow

This workflow is also experimental. Test it in a separate world before trusting it in a real save.

The standard blueprint flow looks like this:

select an existing structure with point A and point B
switch to BlueprintSave
save the structure as a blueprint
open blueprint management and activate the blueprint
set the placement position
rotate or mirror if needed
switch to BlueprintBuild
let the mod place blocks from your inventory
switch to CleanSupportBlocks if you want to remove temporary supports afterward

Important Settings

Common settings include:

selection tool name
action delay
render distance
whether region rendering stays visible without holding the tool
slab and stair placement preferences
auto-sneak learned block list
blueprint directory
temporary fill block
auto-clean mismatched blocks during blueprint work
auto-clear surplus blocks in blueprint space
configure interactive blocks during building

If you want to regenerate the default config, delete ~/.minecraft/config/buildhelper.json and launch the game again.

Who This Is For

Build Helper is especially useful for players who:

build large structures regularly
repeat the same shapes or patterns often
want to save builds and reconstruct them as blueprints
dig a lot of structured tunnels or stair systems
work in dangerous areas with lava or fire nearby

Build-Helper-Mod