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Does a newer iPhone make the scan more accurate?

Only slightly — and far less than how you scan. Here is what the phone actually decides, and what is up to you.

What the phone decides

A LiDAR scan of a home rests on two things the phone does at the same time: it measures distances with the LiDAR sensor, and it keeps track of its own position by recognising detail in the camera image. Both have been in place since LiDAR arrived in the iPhone 12 Pro.

Newer models have got better at things that sit outside the measurement itself:

• Faster chip — the scan is processed faster, and large homes put less strain on it.
• Better camera in low light — more usable detail to recognise when the light is poor. This helps against drift in dark rooms.
• More memory — fewer problems when scanning many rooms in one stretch.
• Better cooling — a long scan heats up the phone, and a hot phone throttles itself.

None of the four changes what happens when the LiDAR light hits a mirror.

What actually decides the accuracy

The errors that shift the measurements in a home scan come almost entirely from the room and from you — not from the hardware:

1. Mirrors. A mirror bounces the light onward instead of back, so the scan measures the distance to the reflection. This creates a phantom room behind the wall. Happens on every phone.
2. Clear glass. Some of the light passes straight through the patio door. Happens on every phone.
3. Furniture along the walls. The front edge of the bookcase becomes the wall. Happens on every phone.
4. Your pace. Fast movements give blurred images and therefore worse position tracking. A better camera helps a little — walking slower helps a lot more.
5. Broken-off scans between rooms. If you stop and start over in the next room, the app does not know how the rooms connect. Pure technique, not hardware.

The order is worth noticing: the top three are properties of the room, and the bottom two are properties of your behaviour. The phone model is not on the list.

Why there is no accuracy figure per model

You might wish for a table: iPhone 13 Pro this accurate, iPhone 17 Pro a bit better. That table would not make sense, because accuracy varies more between two rooms than between two models. The same phone can measure an empty, well-lit living room with matte paint far closer to reality than a bathroom with a mirrored wall and glossy tiles.

So the only useful answer is a check you do yourself: measure one long wall with a tape measure and compare it with the scan. That check applies to your phone in your room — and that is the only accuracy that is worth anything.

Example: the tape measure says 487 cm, the scan says 492 cm. The difference is 5 cm, 5 ÷ 487 × 100 = 1.0%. That figure says more about your scan than any model comparison.

When a newer phone actually helps

There are three situations where upgrading is an argument — but it is about speed and stamina, not centimetres:

• Large homes in one stretch. If you need to scan 200 m² across two floors without stopping, a faster chip, more memory and better cooling all help.
• Many scans in one day. If you are an estate agent or a contractor scanning five homes, battery and heat are the real limitation.
• Dark basements and evening viewings. A better low-light camera gives less drift — but a torch or a work lamp switched on helps more than a new phone.

Five free habits that matter more than an upgrade

1. Turn on every light in the whole home, including rooms you only pass through.
2. Cover mirrors with a towel and draw curtains across large glass sections.
3. Walk at a calm pace and pause for a couple of seconds in each corner.
4. Keep the scan running through doorways, and let the camera see the door frame from both sides.
5. Walk two rounds in rooms with bookcases and wardrobes — one along the floor, one over the furniture.

These five habits cost nothing and remove most of the errors that can arise at all.

Have you got no LiDAR at all?

An iPhone without "Pro" in the name has no LiDAR — not even the expensive Plus models. That does not mean you cannot get a measured floor plan. In HouseSense the home can be drawn on graph paper instead: you drag the rooms out with your finger and type in your own tape-measure numbers in whole centimetres. Walls snap together into one shared wall, so two rooms never count the same square metres twice.

The accuracy of a drawn home is exactly as good as your tape measure — and that is actually the most checkable accuracy there is, because every number is one you took yourself.

What HouseSense does

HouseSense works with LiDAR scanning on iPhone and iPad Pro models that have the sensor, and with drawing on all others. The app reports every measurement as an internal measurement — from wall surface to wall surface — so it can be checked with a tape measure, whether it comes from a scan or from your own drawing.

HouseSense does not advertise an accuracy figure in centimetres, and that is a deliberate choice: the app cannot measure better than the phone does in that particular room, and a number that cannot be trusted is worse than no number. The principle is that the drawing may be dressed up — the numbers may not.