How LiDAR works
LiDAR stands for Light Detection and Ranging. The sensor fires thousands of invisible infrared laser pulses per second and measures exactly how long each pulse takes to return after bouncing off a surface. Because light travels at a known speed, the return time translates directly into a distance. The sensor does this across the entire field of view, building up a dense point cloud — a 3D map of every surface in range.
In a smartphone, the LiDAR sensor sits alongside the camera. It runs continuously while you scan a room, measuring every wall, floor, ceiling, and object in real time. The result is not a photograph — it is a geometric model made from millions of individual distance readings.
This is fundamentally different from how a standard camera works. A camera records light intensity and color. It has no direct way to measure distance. Any depth information a standard camera produces is inferred, not measured.
LiDAR vs. standard camera: what the difference means in practice
A standard camera estimates depth from images using algorithms — a process called photogrammetry. The camera takes overlapping photos from slightly different angles and computes depth by comparing them. This works reasonably well for photography but is not reliable enough for dimensional documentation.
| Factor | LiDAR sensor | Standard camera |
|---|---|---|
| Depth measurement method | Direct — laser pulse timing | Estimated — algorithm inference |
| Accuracy for room scanning | Within 1% — about 1–2 cm per wall | Varies widely — degrades with distance |
| Performance in low light | Unaffected — uses infrared, not visible light | Degrades significantly |
| Works in featureless rooms | Yes — measures geometry directly | Unreliable — needs visual texture |
| Floor plan output | Automatic — geometry is real measurements | Manual redraw required |
| Suitable for professional documentation | Yes | No |
The practical consequence is this: a floor plan generated from LiDAR data has real dimensions. A floor plan generated from standard camera depth estimation has approximate dimensions. For anything that will be imported into CAD, used for energy calculations, or handed to a contractor, the difference matters.
LiDAR vs. photogrammetry vs. dedicated laser scanner
LiDAR sits between photogrammetry (camera-based depth estimation) and professional terrestrial laser scanners on the accuracy and cost spectrum. Each method is appropriate for different tasks.
Camera-based estimation
Works on any smartphone. Accuracy varies — typically ±5–10 cm per room. Suitable for rough sketches, not for professional documentation or CAD import.
Direct measurement, mobile
Accuracy within 1% — about 1–2 cm per wall. Sufficient for renovation planning, energy assessments, as-built surveys, and CAD workflows. Runs on iPhone Pro or iPad Pro.
Sub-millimeter precision
Devices like Leica BLK or FARO Focus deliver 1–3 mm accuracy. Cost: €5,000–€50,000+. Required for structural engineering, industrial documentation, or heritage recording.
For the large majority of professional building documentation — renovation, energy audit, as-built survey, lighting or electrical planning — smartphone LiDAR delivers the accuracy the job requires, at a cost and time that makes it practical on every site visit.
When LiDAR accuracy matters — and when it does not
LiDAR accuracy of 1–2 cm per wall is sufficient for most professional documentation work. There are cases where it is more than enough, cases where it is exactly right, and cases where a higher-precision instrument is necessary.
| Use case | Required accuracy | LiDAR sufficient? |
|---|---|---|
| Renovation planning | ±2–5 cm | ✓ Yes |
| Energy audit documentation | ±2–5 cm | ✓ Yes |
| As-built survey for CAD | ±1–3 cm | ✓ Yes |
| Lighting and electrical planning | ±2–5 cm | ✓ Yes |
| Material quantity calculation | ±2–5 cm | ✓ Yes |
| Custom joinery / fitted furniture | ±2–5 mm | ✗ Tape measure or laser meter more appropriate |
| Structural engineering survey | ±1–3 mm | ✗ Professional laser scanner required |
LiDAR is not the right tool for every job — but it is the right tool for the majority of professional building documentation tasks. For millimeter-precision work, a dedicated instrument is more appropriate.
Which devices have LiDAR?
Apple introduced LiDAR to the iPhone with the iPhone 12 Pro in 2020. Since then, it has been standard on all iPhone Pro and Pro Max models. The iPad Pro has included LiDAR since the 2020 model. No Android smartphone currently ships with a room-scale LiDAR sensor.
The current LiDAR-equipped devices are iPhone Pro models from iPhone 12 Pro to iPhone 17 Pro (released September 2025), and iPad Pro models from 2020 onwards. Standard iPhone models — including the iPhone 17 and iPhone 17 Air — do not have LiDAR.
For a full device compatibility list and a comparison of iPhone Pro vs. iPad Pro for room scanning, see the related article: Which Smartphones Can Scan Rooms in 3D?
Frequently Asked Questions (FAQ)
Metaroom is a professional floor plan scanning app for iPhone Pro and iPad Pro. It uses the LiDAR sensor built into these devices to measure room geometry directly — producing a dimensioned 2D floor plan and 3D model automatically after each scan. Accuracy is within 1%, or about 1–2 cm per wall. Results export to PDF, DXF, IFC, Excel, and 30+ other formats. A 3-room apartment scans in 10–20 minutes.
