01
Three presets and a 2D sketch canvas
Start from the House, L-Shape or Gable Cottage preset with one click, or draw a footprint on a true-to-scale 2D canvas with snapping and orthogonal guides — placing doors, windows and interior walls as you go.
Free Modular Building Generator for UE5
Keystone Lite
Keystone Lite is the free edition of Keystone — Modular Building Generator. It builds game-ready 3D buildings (walls, floors, roofs and approximate interiors) right in the Unreal Editor: pick one of three starter presets or draw a footprint on a true-to-scale 2D canvas, tune the parameters in a live 3D preview, then bake to Nanite static meshes with collision that you own outright. It runs on the same deterministic, test-covered geometry core as the full Keystone — a focused free slice, with no AI, no credits and no subscription. Upgrade to the full Keystone for AI text/floor-plan input, multi-volume castles and towers, Kit Mode, the full detailing toolkit, and JSON import/export.
★★★★★Trusted by UE devs Lifetime licence · free updates
Free
No subscription, no credits
3
Starter presets
Nanite
Bakes to StaticMeshes + collision
5.3–5.8
Engine versions (one build each)
Why Keystone Lite
Built for the way you actually work.
02
Live preview and parametric editing
An interactive editor panel shows a live 3D preview and one-click spawn in front of the viewport camera. Tune every building parameter and watch the preview follow. Fully deterministic, with no external dependencies and no AI.
03
Bake to Nanite, own the mesh
Bake the result to standard Unreal StaticMeshes with collision and optional Nanite, and drop it straight into your level. The baked building is yours, with no runtime dependency on the plugin.
Highlights
Everything in the box.
- ✓Runs the same deterministic, test-covered geometry core as the full Keystone — a focused free slice of it.
- ✓Upgrade to the full Keystone for AI text/floor-plan input, multi-volume castles and towers, Kit Mode, full detailing and JSON import/export.
Under the hood
No surprises at install.
Documented, supported, and built to survive engine upgrades.
Engine
Unreal Engine 5.3 – 5.8 (one compile-verified build per version)
Type
Code plugin · editor tool · 0 Blueprints (output is StaticMesh assets)
Modules
BGCore · BGGeometry · BGEditor · BGFeedback (4)
Dependencies
Geometry Scripting + Modeling Tools (ship with Unreal, auto-enable)
Platform
Windows (Win64) editor tool · baked meshes run on any target platform
AI features
None — the optional AI input lives only in the full Keystone
Licence
Free · Fab Standard licence · personal & commercial
Guides & tutorials
Featured in articles
articleKeystone Lite: A Free Modular Building Generator for UE5A free, no-AI slice of Keystone for Unreal Engine 5 — three presets, a true-to-scale 2D sketch canvas, parametric editing with live preview, and one-click baking to Nanite static meshes with collision you own.
comparisonKeystone vs Keystone Lite: Which UE5 Building Generator to UseAn honest, capability-by-capability comparison of the free Keystone Lite and the full Keystone ($29.99) for Unreal Engine — same deterministic core, different reach.
articleProcedural Architecture & Worldbuilding in UE5: Fill Worlds FasterA practical guide to populating Unreal Engine 5 worlds with varied, game-ready buildings — without hand-modelling every one — and where a deterministic building generator fits the workflow.
tutorialProcedural Building Generator for UE5: A Keystone TutorialFive ways to start a building, one editable building file, and a Nanite bake — how to make game-ready 3D buildings in Unreal Engine 5 with Keystone.
Get it free
FreeFree on Fab · free updates
Lifetime licence on Fab. Use in unlimited personal & commercial Unreal projects.
▸ Coming soon Upgrade to the full Keystone — want early access?