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Viewing kit
Your phone as a tape, level, sound meter and compass at a viewing.
Runs on this phone. Nothing is uploaded. How
Noise
Hold the phone at arm’s length, keep quiet, tap Start. 10 seconds per room or by an open window.
Accuracy and calibration
Phone microphones differ. Without calibration expect about ±10 dB; calibrated against a sound level meter, about ±3 dB. Echo cancelling and auto gain are switched off where the browser allows.
Mapped road and rail noise here
Sunlight
Stand at the window, phone flat, top edge pointing outside.
Direction from the map instead: open Map measure, choose “Window direction”, tap the window then a point straight out from it.
Level
Lay the phone flat on the floor.
Two readings with the phone turned round cancel the phone’s own error. Thresholds are a Keys and Costs rule of thumb, not a building standard.
Measure from a photo
Hold an A4 sheet or bank card flat on the wall, take a photo, tap its 4 corners, then the 2 ends to measure.
Choose a photo.
Paint, wallpaper and carpet
Signal and speed
Test on the home’s Wi-Fi if you can, then on mobile data with Wi-Fi off.
Measures this phone’s connection to our server right now (download and response time, about 4–8 MB of data). It is not the line speed the home can get.
Fixed broadband and mobile coverage at the postcode
Map measure
Map: © OpenStreetMap contributors. Areas from your taps on the map are estimates (±5% or more for small shapes); boundaries on the map are not legal boundaries.
Viewing notes
Compare
Your data stays on your phone
- Sound, compass and motion readings are processed in this page only; nothing is recorded or sent.
- Notes and measurements are kept in this browser’s storage (localStorage); photos in its database (IndexedDB). Clearing site data or “Delete all” removes them.
- Only two things use the network: the speed test (downloads test files from this site) and postcode/map look-ups (postcode files from this site, map tiles from OpenStreetMap, noise data from Defra). None of them include your notes, photos or readings.
- Every number here is an estimate with its likely error shown. It is not a survey, valuation or professional measurement.
Sources
- Sun position: SunCalc method (V. Agafonkin, BSD-2-Clause), checked against NOAA solar equations · 2026-11-05
- A-weighting: IEC 61672-1 formula
- Card and paper sizes: ISO/IEC 7810 ID-1, ISO 216 A4
- Defra – Strategic noise mapping (Round 4, 2022), Open Government Licence v3.0
- Ofcom – Connected Nations