A check log documents, for every automatically measured area, where it comes from and how certain the detection was, so that a third party can verify it without measuring again. Confidence here is a measure of detection certainty – not of accuracy against the building. Keeping the two apart is the core of a traceable process.
In short
- Confidence asks: how reliably did the software read the plan? Accuracy asks: how close is the result to the building? Only a survey answers the second question.
- The source reference is the way back – from every figure to the place in the plan it came from.
- Sign-off stays with a person; the log makes it verifiable.
Definition
A check log for areas taken from plans contains at least: the plan source with revision and origin of the scale (dimension chain, stated scale, estimate); the detected geometry per room with source reference in the original plan; the standard and calculation rule applied (DIN 277, WoFlV); the confidence per item; flags for uncertain detections, incomplete dimension chains and rooms without a closed outline; editor and sign-off with date.
Confidence arises in the detection step – a model rates how unambiguous a wall, a door, a room was in the image. Accuracy is a property of the result against reality and can only be established by comparison with a measurement. A plan can be read with high confidence and still be wrong if the building was built differently.
Distinction
| Term | What | Who measures it | What for |
|---|---|---|---|
| Confidence | certainty of detection in the plan | the software, per item | order of checking: uncertain items first |
| Accuracy | deviation of the result from the building | comparison with the survey | statement whether the figure holds |
| Tolerance | permissible deviation under a set of rules or a contract | standard, contract, case law | decision whether a deviation has consequences |
In practice
Anyone reading a check log starts with the low confidences and the flags – that is where it is decided whether the result holds. For documented proof under VOB, a living area calculation or the initial population of a CAFM system, the log is the answer to the question “Where does this figure come from?” – and the evidence that detection and calculation are separate: detection reads the plan, a calculation computes deterministically, and every step is documented. Pure language models do not deliver this; they estimate instead of calculating.
Normraum relevance
In Normraum, every room carries a confidence and a source reference in the original plan; the check log documents standard and calculation path and flags uncertain detections and incomplete dimension chains. The area itself is calculated by a deterministic geometry engine – same input, same result. The confidence says how certain the detection was, not how closely the plan matches the building: sign-off and survey remain with people.