Is the Stairs 3D model free for commercial use?

Yes. It is free under the 1DesignTool 3D library license: use it in personal and commercial work — games, apps, websites, renders, ads and client projects — and modify it as you like, with no credit required. What you can't do is re-sell or re-distribute the file on its own or inside a model pack.

What file format is it, and how big is it?

A single binary glTF 2.0 file (.glb), 149 KB: 1,856 triangles, 5,568 vertices and 19 materials, modelled in metres at 92 cm × 3.7 m × 3.0 m.

Can I animate Stairs?

It ships as a static mesh. Its 28 named parts are separate nodes, so you can move or animate each one in your engine.

Which engines and tools can open it?

Anything that reads glTF 2.0. three.js, React Three Fiber, Babylon.js, Godot 4 and Blender import the GLB directly; Unity and Unreal Engine load it through their glTF importers. The snippets above show the exact code for three.js, React Three Fiber, Godot and Blender.

How was the Stairs 3D model made?

Claude Code (Claude Opus 5.5) generated it inside 1DesignTool's 3D template from a written brief, then the design kit's checks verified the geometry and the GLB before it was published. You can make your own the same way with 1DesignTool.

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Stairs

A low-poly straight timber basement staircase: dark-wood sawtooth stringers, worn brown treads over dark risers, a handrail with square balusters and a caged amber lamp on the top post, a forgotten paint can and jar on the steps, and dust and cobwebs underneath. Modular — a whole-metre run that snaps on a 1 m grid.

Original GLB149 KB Poster

Left rail: colours and the 5 knobs the agent wrote into this model — they rebuild the geometry and go into your download. Right rail: looks for the viewer. Drag to orbit, scroll to zoom.

Triangles: 1,856
Vertices: 5,568
Meshes · materials: 19 · 19
Size (W × H × D): 92 cm × 3.7 m × 3.0 m
File: GLB · 149 KB
Animation: Static
Style: Low-poly
Collection: Attic and Basement

Palette · named materials

dark wood — stringers, support posts, newel and top posts, rail (trim)#3d2a1c
dust brown — treads and balusters (accent)#6b4a2e
dust brown dark — risers, ledger, post caps, jar lid (trim)#362517
soot black — lamp base and cage (trim)#1b1b22
bulb amber — the lamp bulb, lightly emissive (accent)#ec9c13
faded colours — paint can and translucent cobweb film (accent)#a6a6a6
mid grey — paint can lid (base)#7d828c
cobweb grey — jar (base)#757e8a
cobweb grey light — dust drifts on the treads (trim)#a3a5a8
warm white — cobweb strands (base)#f2ede2

Use it

import { GLTFLoader } from "three/addons/loaders/GLTFLoader.js";

const gltf = await new GLTFLoader().loadAsync(
  "https://assets.stoicsoft.com/1designtool/3d/models/attic-and-basement-stairs/fc3532bbd6/model.glb"
);
scene.add(gltf.scene); // metres, +Y up, front faces +Z

How it was made

The brief given to 1DesignTool's “3D object” template:

Stairs for the Attic and Basement kit. Design it as one clear asset at believable real-world scale for that setting (state the size in metres in meta.notes), with its main parts modelled and named, readable at thumbnail size and from every orbit angle. It is a modular piece that snaps on a 1 m grid: give it a length in whole metres and put the origin at its snapping end, stated in meta.notes. This is one part of the Attic and Basement kit (Low-poly style, flat-lowpoly direction): Forgotten things above and below. Use ONLY the kit palette, by name: dust brown #6b4a2e, cobweb grey #757e8a, bulb amber #ec9c13, faded colours #a6a6a6, dust brown dark #362517, cobweb grey dark #525860, dust brown light #9b704b, cobweb grey light #a3a5a8, soot black #1b1b22, warm white #f2ede2, mid grey #7d828c, dark wood #3d2a1c. Every material's `name` must be exactly the palette colour it uses — the GLB carries these names so the kit recolours as one; an unnamed material fails delivery. Kit knob: expose a param `dustAndCobwebLevel` (0–1, default 0.5) for the kit's "Dust and cobweb level" setting wherever it makes sense on this part, and keep that id.

Agent: Claude Code · Claude Opus 5.5 in 1DesignTool
Direction: Low-poly · family scenes
three-check PASS · glb-lint PASS

Make your own with 1DesignTool →

Named parts · 28

Stairs
Stringers
Right stringer
Left stringer
Treads
Tread boards
Risers
Riser boards
Support posts
Posts
Ledger
Handrail
Newel and top posts
Post caps
Rail
Balusters
Caged lamp
Base and cage
Bulb
Forgotten things
Paint can
Can lid
Jar
Jar lid
Dust and cobwebs
Dust drifts
Cobweb film
Cobweb strands

Note: Size: 3 m run × 0.80 m stair width (inside a 1 m wide footprint, x −0.48 to 0.48), 2.40 m floor-to-floor rise in 12 steps of 0.20 m rise × 0.25 m going (about 39°). It is 3.66 m tall to the top of the lamp on the top post. Snapping: the run is always a whole number of metres (runLength 2–4, four steps per metre) and climbs toward −Z. The origin is the snapping end — the foot of the flight, bottom centre, where the first tread's nosing meets z = 0 — so the footprint is z −L to 0. The top tread ends flush at z = −L and height L × 4 × stepRise, ready to meet an upper floor. The model rests on y = 0 (stringer feet, newel and support posts). 1,856 triangles, counted from the GLB accessors; three-check's figure (2,218) also includes the viewer's staging ground, which is not exported. Static: no animation clip. dustAndCobwebLevel scales the dust drifts at the back of each tread and sets the size and number of cobwebs under the flight (1 to 4). At 0, one small cobweb remains so the dust part always exists. railSides 1 puts the rail on the +X side only; 2 adds a mirrored rail on −X, and the lamp stays on the +X post. The cobweb film is a translucent (BLEND) material named 'faded colours', the same name as the opaque paint can, so the kit recolours both together. The bulb is emissive and the model contains no light. Every material is named exactly after its kit palette colour; three.js's exporter writes one material per mesh, so names repeat (19 materials, 10 distinct names). plan-check's part-id pattern rejects the hyphenated slug ids the brief requires; the plan passed plan-check with the hyphens removed and is otherwise unchanged. Both param extremes (all max, all min) passed three-check in separate runs. glb-lint: 0 errors. It warns on material count, non-indexed flat-shaded geometry, height versus a 1 m reference, expected sibling overlaps (rail into posts), and 'detached' clutter and dust that rest on treads in another part group.

About the Stairs 3D model

Stairs is a free low-poly 3D model from the Attic and Basement set. It measures 92 cm × 3.7 m × 3.0 m (W × H × D) at real-world scale and is built from 1,856 triangles across 19 meshes, with 28 named parts. Download the 149 KB GLB and drop it into three.js, React Three Fiber, Godot or Blender — free for commercial use, no attribution required.

Is the Stairs 3D model free for commercial use?: Yes. It is free under the 1DesignTool 3D library license: use it in personal and commercial work — games, apps, websites, renders, ads and client projects — and modify it as you like, with no credit required. What you can't do is re-sell or re-distribute the file on its own or inside a model pack.
What file format is it, and how big is it?: A single binary glTF 2.0 file (.glb), 149 KB: 1,856 triangles, 5,568 vertices and 19 materials, modelled in metres at 92 cm × 3.7 m × 3.0 m.
Can I animate Stairs?: It ships as a static mesh. Its 28 named parts are separate nodes, so you can move or animate each one in your engine.
Which engines and tools can open it?: Anything that reads glTF 2.0. three.js, React Three Fiber, Babylon.js, Godot 4 and Blender import the GLB directly; Unity and Unreal Engine load it through their glTF importers. The snippets above show the exact code for three.js, React Three Fiber, Godot and Blender.
How was the Stairs 3D model made?: Claude Code (Claude Opus 5.5) generated it inside 1DesignTool's 3D template from a written brief, then the design kit's checks verified the geometry and the GLB before it was published. You can make your own the same way with 1DesignTool.