Defect documentation the warranty paperwork can rely on
Site manager flags an issue. Subcontractor joins the session live, sees what the site sees, marks the surface. The annotated snapshot lands signed at session-end — straight into the snag list, the handover pack, and the warranty file. No "I never saw that" three weeks later.
Three workflows it lands on
Site manager + sub on a call
Site walks the floor; subcontractor (electrician, plumber, framer) joins remotely. Both see the same camera feed, both annotate the same canvas. The snag is captured with timestamp, GPS, and both parties' identities — no "send me a photo" lag.
Client walk-through, signed
Run the PC walk-through as a session. Client and project manager both joined, every defect logged into the audit chain, signed PDF at the end with both names on it. Whatever's not in the report on day-of-handover isn't on the snag list.
Latent-defect documentation
Owner reports a defect inside warranty. Run a remote inspection; capture the defect with chain-of-custody intact. The signed pack is what your subcontractor's insurer sees — and what the litigation file references if the warranty period dispute lands in court.
What makes it stick at the warranty stage
Defect litigation often runs 6–10 years after completion in the EU (depending on jurisdiction — France's garantie décennale, Germany's Mängelhaftung, the UK's Defective Premises Act). Whatever you produce at handover has to be verifiable that far out. A chain anchored at a qualified TSA gives you cryptographic continuity from the day-of-handover snapshot to the day-of-litigation auditor — without trusting that your CDE provider still exists.
| Capability | Why warranty cases need it |
|---|---|
| Excalidraw + PNG anchored together | The annotated overlay plus the underlying photo, both hashed — so "the mark was added later" isn't an argument anyone can make. |
| Multi-party joined audit chain | Site manager + subcontractor + client all in the same session; their join + leave events are in the chain. No "I wasn't there" defence. |
| 7-year retention (extendable) | eIDAS-aligned default; lift to 10+ via S3 lifecycle policy for the décennale window. |
| Verify URL outlives the contract | Auditors hit the verify endpoint; the qualified-TSA receipt validates offline against the EU Trust List even if we're not around. |
Fits the existing CDE flow
Common Data Environments (Procore, Aconex, Asite, Dalux) already store the photos. NexBasira doesn't replace them — it adds the cryptographic witness around the moments that matter (snagging, handover, warranty inspections). Pull the signed PDF + evidence index into your CDE via the public API on session.completed; the chain itself is queryable separately if a defect file ever needs auditing.
What a typical deployment looks like
Main contractors and developers on residential, commercial fit-out, and infrastructure projects are the natural fit — especially anyone exposed to long-tail warranty obligations (France's garantie décennale, Germany's Mängelhaftung, the UK's Defective Premises Act). Before NexBasira the handover dossier is photos in OneDrive plus a Procore/Aconex snag list, signed by no one in particular. When a defect surfaces six years later and the developer's insurer asks for chain-of-custody, the answer is "here's the folder."
After: site manager flags a snag, subcontractor joins a video session live (no callout needed for the small ones), both annotate the same canvas, signed pack lands in the CDE within the same day. Practical-completion walk-throughs run as sessions where the client visibly joined and signed — the snag list at handover is unambiguous, and warranty-period inspections share the same audit-chain hash so the legal continuity stretches to litigation horizon.
Ranges to expect
Pulled from the cost model + pilot conversations. Construction outcomes vary widely by project type and warranty exposure — these are the ranges we've consistently seen in early conversations.
| Lever | Typical range |
|---|---|
| Snags closed per site-walk hour | 5–10 (callouts + paper trail) → 15–25 (live remote subcontractor) |
| Subcontractor on-site visits avoided | 2–4 per project, depending on snag-list size + subcontractor mix |
| Time from defect → documented | 1–3 days (photo-by-email) → same-hour (live capture in-session) |
| Warranty-period defensibility | Qualitative — the qualified-TSA chain validates offline against the EU Trust List 6–10 years later, which is what décennale-style litigation asks for |
Walk a snag with us
Send us a fake snag list from your last completed project; we'll run the documentation flow on a sandbox tenant in 15 minutes. You'll see how the chain holds up — and how it threads into the CDE you already use.