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What files can I get out of a home scan?

Three kinds: the drawing (PDF and DXF), the model (OBJ, STL, PLY, glTF, GLB, DAE, USDZ), and the raw measurement points (PLY, XYZ, PTS, LAS) — and the choice depends only on who has to open it.

The three kinds of files — and why none can replace the others

It is easier to pick a format once you know there are three entirely different things at play:

• The drawing is the home seen from above as a horizontal slice: walls, doors, windows, room names and measurements. It is 2D, and it is the one everything actually gets built from.
• The model is the home in three dimensions: surfaces that can be seen from every side. It is good for understanding a room and poor for building from.
• The measurements are the point cloud: the raw measurement points the scan actually recorded, with no interpretation of what is a wall and what is a curtain.

An architect wants the drawing. A 3D printer wants the model. A surveyor or an engineer who needs to verify something wants the measurements. Send the wrong one, and you get an email back, not an answer.

The drawing: PDF and DXF

PDF is the drawing as a fixed image. It looks the same on every device, can be printed to scale (at 1:50 or 1:100), needs no software, and cannot be changed by accident. It is the file you send to a tradesperson giving a quote, to the bank, to the insurer and to your partner.

DXF is the drawing as vectors: every wall is lines with real coordinates, sorted into named layers — exterior wall, interior wall, door, window, opening, room name, area, furniture. It is the file you send to an architect, a design office or a kitchen company that needs to keep drawing on it. DXF is Autodesk's own, open exchange format, and it is read by AutoCAD, Revit, ArchiCAD, SketchUp and LibreCAD.

If someone asks for DWG, DXF is the answer. DWG is Autodesk's closed binary format with no open specification, and in practice it cannot be written by an app on a phone.

The model: seven formats, three choices that matter

The 3D model can be written in many formats, but in practice you only make three choices:

• USDZ — if the recipient has an iPhone, iPad or Mac. Opens directly in Messages, Mail and Files, carries the look of the materials, and can be placed in AR.
• GLB — if the model is going on the web or into Blender, Unity or Unreal. One self-contained file with geometry and materials inside it. Also available as glTF in a split version with a .bin file alongside it.
• OBJ — if you don't know anything about the recipient. The oldest and most widely read format. Remember that the colours sit in a separate MTL file, which has to be sent along with it.

On top of that, three special cases: STL for 3D printing (cannot carry colours at all), DAE for SketchUp and older CAD software, and PLY, when the model needs to be treated as scanned data with a colour per vertex.

The measurements: the point cloud in four formats

The point cloud is the scan's raw output: hundreds of thousands of points with position and colour. There are no walls and no rooms in a point cloud — only points, sitting where the surfaces were.

• PLY — the most common. Can be saved in binary and carries a colour per point. Opens in CloudCompare and MeshLab.
• XYZ — plain text, one line per point. As simple as it gets, read by everything, but the files get large.
• PTS — the surveyor's text format, with the point count on the first line.
• LAS — the binary format from surveying. Compact, and the one a surveyor most often asks for.

Watch the orientation: graphics programs typically assume Y points upward, while surveying tools expect Z to point upward. If the house arrives lying on its side, that is almost always what happened. HouseSense therefore writes PTS and LAS with Z pointing up, while PLY and XYZ face the same way as the 3D model.

The reports: the part that isn't geometry

A large part of the value in a home scan isn't files with shapes at all, but numbers on paper. They come as PDF, because they need to be printable, archivable and attachable to a quote request:

• Floor plan for the whole home and per room, with dimensions and areas.
• Takeoff per room and in total — floor area, net wall area, ceiling area, skirting length. What a painter or a flooring contractor prices from.
• Window and door schedule with numbers that point back to the drawing.
• Budget and checklist, if you have kept them.

In HouseSense you choose the rooms and the content yourself before the report is assembled — and you can choose which language the PDFs are written in, if the tradesperson doesn't read Danish.

What to send to whom

• Carpenter, painter, flooring contractor, bricklayer: PDF with plan, takeoff and schedule.
• Architect, design office, engineer: DXF in metres plus a PDF of the same drawing.
• Kitchen company: DXF of the room in question, plus the ceiling height.
• Estate agent: PDF with plan and areas.
• Family and partner: PDF — or USDZ, if they're on iPhone and want to see the room.
• Surveyor, or anyone who needs to verify the measurements: point cloud in LAS or PLY.
• The 3D printer: STL, scaled to 1:100.

Always write down the unit, the scale and the measuring method

Three lines in the email prevent the mistakes that otherwise cost days:

1. The unit. "DXF in metres" or "the model is in metres." A file read in the wrong unit makes the house 4 cm or 4 km wide.
2. The scale. "PDF at 1:50, print at 100%, don't fit to page."
3. How it was measured. "Measured by myself with a LiDAR scan on iPhone on [date], internal measurements." That tells the recipient what can be built on directly, and what needs to be checked on site.

That last point is also a matter of honesty. A takeoff made by a homeowner is a good working basis, but it is not a professional surveyor's measurement — and it never decides whether a wall is load-bearing. That question belongs with a building surveyor or a consulting engineer, however many file formats the drawing comes in.