The order looked safe: a 160 centimetre desk into a 240 centimetre alcove, 80 centimetres to spare. Then the monitor arm turned out to clamp on the back edge, which wants 12 centimetres of clearance to the wall. The chair wanted 90 centimetres of swing.
The only power outlet was behind the filing cabinet on the far wall. Eighty centimetres of spare had become minus ten before anything was unpacked. Maker Stations has already covered why a desk setup should be visualised before anything is ordered.
This is the practical half: where the real 3D files of the desk, the chair and the monitor arm come from, how to get them into one scene at true scale, and how to look at that scene standing in the actual room with a phone.
Where the manufacturers’ files are?
The models already exist. Most furniture and monitor brands publish 3D files of their products, because architects and retailers need them, and those files are the exact dimensions of the thing that will arrive in the box. Where they sit depends on the brand.
| Source | What is there | Format it comes in |
|---|---|---|
| Product page, View in your room or AR button | Phone-ready model with the real finish | GLB on Android, USDZ on iPhone |
| Product page, Downloads or Resources tab | CAD and planning files for architects | OBJ, FBX, SKP, sometimes DWG |
| Manufacturer’s page on 3D Warehouse or Sketchfab | The same catalogue models, searchable by product name | SKP or OBJ from 3D Warehouse, GLB or FBX from Sketchfab |
| Free model libraries | Generic stand-ins for anything without an official file | OBJ or FBX, scaled to the spec sheet by hand |
Office chairs and standing desks are the best covered, since contract furniture brands have supplied architects for decades.
Monitors and monitor arms are patchier, and a generic 27 inch monitor model scaled to the width and height on the spec sheet is fine for a layout check. The point of the exercise is size and position, not the reflection on the screen.
Measure the alcove, not the room
The desk lives against one wall, so that wall and the things attached to it decide everything. Record these before opening any software.
| Measurement | Where to take it | Why it matters |
|---|---|---|
| Wall length at desk height | At 72 to 75 cm off the floor, not at the skirting | Skirting boards and leaning walls change the figure by a few centimetres |
| Window sill height and width | Floor to underside of the sill | A monitor arm clamped below a 70 cm sill hits it on the first tilt |
| Outlet and network point positions | Distance from the nearest corner | A desk across the only outlet means a visible extension lead for years |
| Radiator depth and position | Wall it sits on, distance from the corner | A desk pushed against one blocks the heat and warps a wooden top |
| Door swing | Which way it opens, how far | A chair in the arc gets hit every time someone comes in |
One scene, true scale, then the phone
Any 3D program that reads OBJ and FBX will hold the scene. Blender is free and does it, SketchUp Free does it, and so do the paid room planners. The order things go in matters more than the program.
| Order | What goes in | Why at this point |
|---|---|---|
| 1 | Three walls of the alcove at the measured lengths, plus the window as an opening | Everything else is placed against these |
| 2 | Outlets, network point and radiator as marked boxes | They cannot move, so they constrain the desk |
| 3 | The desk | It decides where every other piece can go |
| 4 | The chair, with its full swing drawn as a circle | The swing is the space people forget |
| 5 | Monitors on their arm, then shelves | Last, because they fit around what is already placed |
The step that trips people up is getting the scene onto a phone so it can be checked in the real room. Phones show 3D through GLB, the binary form of glTF, which is the format the Khronos Group maintains as the open standard for web and mobile 3D.
Manufacturer CAD downloads and library models arrive as OBJ or FBX, which phones cannot open. A browser based OBJ to GLB converter turns the desk file, the chair file and the monitor file into GLB in a few seconds each, without installing anything, and the resulting files open in a phone’s AR viewer directly from a link. iPhones want USDZ instead, and the same class of tool produces that from a GLB.
Scale is the thing to check after every import. A file saved in millimetres and read by a program expecting metres arrives a thousand times too large, which is obvious, or a thousand times too small, which is not, because a desk the size of a grain of rice simply looks like nothing imported.
Compare the imported width against the spec sheet before placing anything. A 160 centimetre desk that reads 160 centimetres is a trustworthy file.
The clearances that decide whether it works
With the real pieces in the real alcove, the layout can be judged by numbers rather than by how the render looks. These are the working figures for a single-user desk.
| Clearance | Working figure | What happens below it |
|---|---|---|
| Chair swing in front of the desk | 90 cm from the desk edge | The chair hits the wall or the bed on the way out |
| Walkway behind a seated person | 75 cm or more | Anyone passing turns sideways |
| Monitor arm clamp to wall | 10 to 15 cm behind the desk edge | The arm cannot tilt back and the desk sits away from the wall |
| Eyes to a 27 inch screen | 60 to 70 cm | Closer, and the corners of the screen need head movement |
| Knee clearance under the desk | At least 60 cm wide and 65 cm high | Drawers and cable trays eat this space first |
| Desk top height, seated | 72 to 75 cm, or elbow height | Shoulders lift on a high desk, wrists bend on a low one |
Run the 240 centimetre alcove through those figures with both desk sizes and the answer falls out of the table.
| 160 cm desk, arm at the back | 140 cm desk, arm at the side | |
|---|---|---|
| Gap behind the desk | 12 cm, forced by the arm clamp | 0 cm, flush to the wall |
| Chair swing to the bed | 82 cm, below the 90 cm figure | 91 cm |
| Room under the window | None | A 40 cm drawer unit |
| Cable run to the outlet | 3 m along the skirting | 3 m along the skirting, planned in a tray |
The outlet never moved. What changed is that the cable run was visible in the mockup, so the tray was in the basket with the desk instead of being discovered on delivery day.
What to keep afterwards?
Keep the scene file. The next purchase, whether a second monitor or a different chair, starts from an alcove that is already measured and built, and the check that took an evening the first time takes ten minutes the second. Keep the GLB files too.
They open on any phone from a shared link, which is the fastest way to show a partner or a landlord what the corner will look like before the boxes arrive.
