Expert article
Securing evidence on site: documented is not proven
In court, what counts is not what happened but what can be shown. Whoever holds no evidence after acceptance loses — even when they are in the right.
Expert article by Open Experience GmbH. · As of: August 2026
What does securing evidence mean in construction?
Securing evidence means recording the condition of a building so that it can still be substantiated later, even against contradiction. The reason lies in the burden of proof: until acceptance the contractor has to prove that their work is free of defects — afterwards the client has to prove the defect (§ 640 of the German Civil Code). Because many defects surface only years later and many building elements are closed up by then, today's documentation decides tomorrow's litigation.
Who must prove what — and when
The burden of proof shifts at acceptance. That is why documentation before acceptance serves a different purpose from documentation afterwards.
| Point in time | Burden of proof | What that means in practice |
|---|---|---|
| *Before acceptance* | Contractor proves freedom from defects | The contractor documents in their own interest |
| *After acceptance* | Client proves the defect | Without as-built documentation it gets expensive |
| Concealed building elements | unchanged by the point in time | Without a record before closing up, only opening the element helps |
| Fraudulent concealment | Client proves the fraud | A high hurdle — the exception, not the rule |
Legal basis for the reversal: § 640 of the German Civil Code. The assessment of evidence itself is free (§ 286 of the Code of Civil Procedure) — no item of evidence counts automatically.
What makes a record hold up
A photograph on its own is not proof but an object of visual inspection that the court assesses freely (§§ 371, 286 of the Code of Civil Procedure). Its persuasive force comes from its surroundings: where time, place, author and integrity are traceable, a picture becomes a solid reference point.
- TimeThe timestamp of capture, not the moment of typing it up in the office. A file assembled after the fact loses precisely here.
- PlacePosition on the plan or in the model instead of "image 4711". A crack without a position is worthless in a dispute.
- AuthorWho recorded it, who checked it, who released it.
- IntegrityA complete record in which later changes remain visible. A folder structure on a network drive does not achieve that.
- CompletenessA series with individual days missing raises the question of what was in the gaps. Continuous capture beats hunting for evidence after the fact.
Record it before closing up — the only opportunity
Waterproofing, reinforcement, service runs, insulation: whatever is built over can afterwards only be reached by opening the element, with all the costs and consequential damage that entails. The record before closing up takes minutes and is often the only piece of evidence that shows the condition at the right moment.
Rule of thumb from practice: what you can no longer see, you must have seen. That is exactly what continuous 360° walkthroughs are built for — they also capture what nobody was looking for at the time.
Independent evidence proceedings
Where a condition is at risk of disappearing, or a dispute is foreseeable, the condition can be established by a court-appointed expert without an action being brought yet (§§ 485 ff. of the Code of Civil Procedure). The procedure also suspends limitation and is often used in practice as a route to settlement.
- When it is worth itWhere evidence is about to be lost, where the cause is disputed, and always where a repair would eliminate the condition.
- What it does not deliverIt clarifies the condition, not the legal question. And it takes time — it does not replace your own documentation but builds on it.
- Preparation decidesThe more precisely the application names the symptoms, the more useful the expert opinion. Your own documentation supplies exactly those details.
Five misconceptions that cost cases
"We do have photos"
Ten thousand images without location or allocation are not evidence but a search problem.
"The site diary is enough"
It evidences sequences, not conditions. Together they hold.
"The site manager remembers"
After five years nobody remembers — and witness testimony weighs less than a documented record.
"We do that at month end"
Promptness is a quality of the evidence, not a question of diligence.
"The firm admitted it"
Verbally, without witnesses, without minutes — nothing of it survives in court.
Better
Continuous, located, timestamped, stored unalterably — and done before anyone expects a dispute.
Documentation that arises along the way
Securing evidence rarely fails on willingness, almost always on effort. With Construction Photos it arises as part of the work: every image carries a timestamp and a position on the plan, is assigned to the project automatically and stays findable — five years later too, when nobody remembers what they are looking for. DIGISCHUTZ pixelates people automatically as it goes.
Frequently asked questions
Are digital photographs admissible in court?
Yes. They are objects of visual inspection and subject to free assessment of evidence (§§ 371, 286 of the Code of Civil Procedure). Their weight depends on how well time, place and integrity can be traced.
Do I need a qualified electronic signature?
For the evidential value of an electronic document under § 371a of the Code of Civil Procedure, yes — for site photographs it is unusual and not required. What matters is the traceable chain.
How long should documentation be kept?
At least beyond the limitation period for defect claims. Because of possible secondary liability, considerably longer is advisable.
Does securing evidence help the contractor too?
Them above all. Before acceptance they carry the burden of proving freedom from defects — complete self-documentation is their best defence.
What about images of construction workers?
Site photographs showing identifiable people are personal data. Automatic pixelation solves the problem at source without reducing the evidential value of the building condition.
Is the contractor's documentation sufficient?
Not as the sole basis. The site supervisor owes documentation of their own — and in a dispute someone else's record is quickly called into question.
Evidence that arises instead of being collected.
In 45 minutes we show how photos, 360° walkthroughs and the site diary form a chain that still holds after five years.