Home / Diagnose your building
Free building health diagnostic
Answer a few questions, photograph the problem properly, and get an indicative diagnosis with the evidence behind it. No account needed, and nothing is withheld if you decline one at the end.
Three questions
Age, symptom, location. Live dew point reading returned immediately.
Baseline
Four short groups covering what a certificate cannot tell us: symptoms, occupancy, heating, and what has been done to the building.
Photographs
A guided list of eight shots, each with a reason. GPS data stripped from every image on upload.
Your report
Mechanism, evidence, what is ruled out, free things to try, honest gaps, and sources.
Free tool, no account needed
Will your walls grow mould in today's conditions?
Calculated from live weather for your location and the conditions inside your home, using the method in BS EN ISO 13788. No assumptions are made about your building.
Your thermostat or a room thermometer.
From a hygrometer. They cost a few pounds and are the single most useful thing you can own if you have damp.
Reading current conditions for Gibraltar...
How this is calculated
Saturation vapour pressure from the Magnus formula, published with an uncertainty under 0.6% between -45 and +60°C. Dew point and the mould threshold are derived from it by inversion.
The mould threshold is the surface temperature at which surface relative humidity reaches 80%, the default critical value in BS EN ISO 13788. Required fRsi is (threshold minus outdoor) divided by (indoor minus outdoor), compared against the 0.75 minimum UK regulations set for dwellings.
Nothing is assumed about your building. The tool reports the wall quality your conditions would demand, not a guess at the wall you have. Indicative screening only, not a survey, and no substitute for measurement at the affected surface.
Steps 2 to 4 are not built yet. The full flow, including guided photo capture and a branching report, is prototyped in design/greencode-platform-demo.html. Before it can ship it needs the validated model, PI insurer sign-off on wording and thresholds, a completed DPIA and a staffed escalation route. See DEVELOPMENT.md Phase 3 and 4.
Prefer to talk to someone?
If the situation is urgent, or you already know you need a survey, skip the tool.