PlasterFlow  /  How it works  /  Measuring

Square metres, off a photograph

Stand at the gate, take a picture, and have the elevation measured before you're back in the van. Set the scale off something you know the size of — a door, a course of bricks — outline the wall, take the windows off. The m² works itself out, and it goes straight into the quote.

Watch it work

One elevation, start to finish

Front elevation — 8.4m wide, 5.0m to the eaves
0.00
838mm
A drawn wall, not a screenshot — but the arithmetic is real.

Gross 42.00 m², less a door at 1.66 and two windows at 1.44 each — 37.46 m² of render. That figure lands on the elevation, the elevation goes into the quote, and the material counts come off the same number. You never type it twice.

When the shot isn't perfect

Five ways to get an m²

Square-on is the easy one. Real houses have a fence, a hedge, a neighbour's drive and nowhere to stand back to — so there are four more, and the app tells you which fits what you're looking at.

Photo outline

Two taps on something you know the size of, then outline the wall. The one in the demo above.

When you can stand back square

Angled photo

Tap the four corners of anything rectangular in the shot — a window, a door, a panel — and give its real size. The angle is worked out and taken off.

When you can't get square on

Two walls at a corner

Both walls of a corner in one photo. The corner ties them to a single scale, so one known length on the front sizes the side as well.

A gable and a front in one shot

Known wall area

No reference object anywhere — render off in patches, nothing square left to tap — but you already know the wall's area. The area becomes the scale, then the openings come off it.

Patchy walls, nothing to measure from

Block or brick count

Count across, count up. No photo maths at all, so perspective can't fool it. This is the one the others get checked against.

The most trustworthy figure in the app

Or look the property up

Type the postcode. If the house has an energy certificate, the assessor's own wall perimeter and storey heights give an external wall area per floor — party walls already excluded.

Pricing an enquiry over the phone
Inside, for plastering

Walk the room. Don't tape it.

Everything above is an elevation, off a photo. Inside is different — you're stood in the room. So on an iPhone Pro, hit Scan on the room card and walk round it. The phone reads the walls as you go, and the length, width and height land in the card with the doors and windows already deducted.

Then the scope of works, the materials and the price come off it exactly as if you'd typed it — because as far as the rest of the app is concerned, you did.

What it fills in

Length, width and height, plus the opening deductions wall by wall. Everything the room card wanted you to key in with a tape in your teeth.

One walk round the room

Needs an iPhone Pro

It uses the LiDAR scanner, which is only on iPhone 12 Pro and later, and iPad Pro. On any other phone the button simply isn't there.

Typing the sizes always works

It tells you when it's wrong

A scan models the room as a box. A room with a chimney breast in it isn't one — on a real test that read 38.4 m² against 45.6 m² measured. So when the shape doesn't fit a box, the app says so in amber and shows you both figures.

A quiet under-read is an under-quote
Worth saying plainly

Zoom in before you tap

The maths is not the weak point — your taps are. The same wall outlined zoomed-out came to 13.99 m², and 15.32 m² tapped in close. That's about 1.3 m² of render between the two, on one elevation.

So while you're outlining, the app shows you what one tap is currently worth on the wall — something like “7 pts · tap 9cm”. Pinch in and that number comes down. It's the difference between a figure you'd price off and one you'd re-check.

And it's an estimate until a tape says otherwise. Good enough to give a price on the phone, or to walk away from a job that was never going to pay. Before you commit to the work, measure it properly — the app will hold both figures.

Measure your next one on the phone

14 days free, no card. Take a photo of the next elevation you're pricing and see whether the number matches what you'd have worked out on the pad.