What it does
APEX Renewables install solar and heat pumps across Scotland. Before either job can be designed, someone has to walk the house and come back with everything: the shape of every room, what each wall is made of, what glazing is in it, where the existing boiler and radiators are, where the outdoor unit could sit, how far the nearest neighbour’s window is, and fifty photographs. That survey used to be a paper form and a phone camera.
It is an app now. The surveyor scans the property in 3D, and the app reads the scan and lays out every room for him — floor area, dimensions, ceiling height, perimeter, wall and window areas, all of it already filled in. He confirms rather than types. It runs the same way for both trades: one app, one shell, a solar journey and a heat-pump journey.
What it saves the man on site
The measuring that used to be the job is mostly gone — the scan supplies the geometry, and he only measures what a scan genuinely cannot see: the radiators, and the thickness of the wall through a window reveal. He types that one number in, photographs the tape, and the app tells him on the spot what that wall is most likely built of. Thirty seconds a radiator, four minutes for a house.
It also quietly removes the mistakes nobody notices until later. Scans come back with rooms the AI could only call “Other 1” and “Other 2”; the app refuses to move on until every one of them is a real room. It knows that a mid-terrace has two shared walls and a detached house has none, so it proposes the wall classifications and asks him to confirm instead of asking him to think. And it checks the address the scanner geocoded against the address on the job, because scanning apps get terraced streets wrong, and a survey filed against the wrong house is a wasted day.
Nothing can be skipped. Every screen validates before it lets him forward, the whole thing validates again before it submits, and tapping back never wipes what he typed. He leaves the house knowing the survey is complete, instead of finding out at the office.
The part that actually made it possible
Two constraints killed the previous version, and both are unglamorous.
The first is signal. Rural Scotland does not have any, and a survey app that needs the internet is a paper form with extra steps. This one runs the entire journey offline, holds everything on the iPad, and syncs when the van gets back into coverage. The surveyor can stop halfway through, close it, and pick it up later with every field intact.
The second is photographs. A survey carries thirty to fifty of them, a quarter of a gigabyte, and the old tool sat behind an eight-megabyte upload limit — which is the actual reason this rebuild exists. Photos are now compressed on the device, queued if there is no signal, retried if an upload fails, and sent straight to storage rather than squeezed through the app. On submit, the whole payload and every photo land in that job’s folder, in the right place, inside a minute.
Where it stops, on purpose
This app captures; it does not decide. It proposes what a wall is likely built of, and the designer confirms or overrides that before anything is locked. The heat-loss calculations, the unit sizing, the pricing and the customer-facing output are a separate phase with their own sign-off. Drawing that line early is what keeps a survey tool honest: it is trusted because it never guesses in the one place a wrong guess would cost somebody a cold house.