Basement, attic, crawl space: scan the corners of your home with an iPhone

Why these spaces are poorly documented

A cellar almost never appears on sale plans, and attic drawings often date from the original build. Photos give neither the dimensions nor the real shape: a vault, a step in a wall or a wall that is not square is hard to see on an image. As for the tape measure, it takes two people and a lot of patience in a space where you can barely stand.

These places also share a lack of light and poor coverage. That is exactly the ground Lidark was designed for: it works with no signal, no GPS and no account, its tracking relies on the camera, and the torch turns on by itself in the dark.

What Lidark records

You start a survey at the entrance of the space, then move on while sweeping the walls with the iPhone. The LiDAR scanner measures surfaces, ARKit tracks your position, and everything is computed on the device.

• The real shape of walls, vaults and floor, including steps and pillars, rather than an idealised rectangle.
• A top-down plan, exportable as an image or a printable PDF, free of charge.
• A 3D model (Lidark Pro) you can rotate, cut and measure in the free viewer, without uploading anything.
• Markers dropped with one tap (free marker, danger, junction): water inlet, meter, hatch, they stay visible on the plan and in 3D.

Scan a cellar in five minutes

The method is the same as for a gallery, only shorter:

• Turn the room light on if you can: the iPhone’s visual tracking is more reliable with it.
• Start a survey at the foot of the stairs, then walk slowly, holding the iPhone at chest height.
• Sweep the walls, the floor and the ceiling without sudden moves. A vibration warns you if you go too fast or if tracking degrades.
• Finish the survey: it is saved on the iPhone with its plan and its 3D model.

Attic and crawl space: precautions

LiDAR reaches about five metres: from a hatch or the top of a ladder, you can already survey most of an attic or a crawl space without going in. That is the right way to go when the space is tight.

Never slide into a space you cannot easily get back out of. A non-load-bearing attic floor, insulation, electrical cables, damp, stale air or animals are real risks, and Lidark detects none of them: it is neither an inspection nor a gas detector. For an inspection, call a professional.

Garage, private car park, basement with no signal

A buried garage or a private car park with no signal is surveyed like a cellar, with the advantage of a clear path between the ramp and the far end. If your need is to find your spot in a big car park, read find your car or the exit of an underground car park.

Get the result and share it

The 2D plan exports for free as an image or a printable PDF, handy for a quote or for your records. The colour 3D model, resuming a survey and PLY, OBJ and GLB export are included in Lidark Pro, a one-time purchase with no subscription.

You can also open the file in the free 3D viewer, straight in the browser, to show it on a computer: it stays on your device. To prepare a building job, see room plan and survey before a renovation.

Its limits, honestly

A few points to know before you rely on it:

• iPhone Pro with LiDAR required: iPhone 12 Pro and later Pro models. Without LiDAR you cannot scan.
• Indicative, not certified: small drifts can build up, and the result is worth neither a contractual take-off nor a surveyor’s plan.
• Difficult surfaces: glass, mirrors, very dark surfaces and a perfectly smooth wall in total darkness disturb tracking.
• Not an architect’s plan: Lidark does not recognise doors, windows or partitions, and does not add dimensions automatically.

Frequently asked questions