what is the Nohl matrix and how is it applied automatically in construction defect documentation

The Nohl matrix is a risk-assessment grid that rates each defect by combining its likelihood of occurrence with its severity of harm, producing a composite risk level — low, significant, or high — that determines how urgently a defect must be addressed. In construction defect documentation, this matrix logic drives automatic prioritization so the highest-risk items surface first for escalation or repair.

WECAVIS applies this structured approach automatically through its WhatsApp-based capture workflow. A field worker photographs a defect and describes it via voice message (supported in 30+ languages including Polish, Turkish, and Arabic). Within 30 seconds, the system generates a timestamped, GDPR-compliant PDF report — no app installation or training required. The defect is automatically categorized and ranked within the defect register according to Nohl matrix criteria, ensuring that risk classification happens at the point of capture rather than during manual office review. Master craftsmen can then review, amend, or approve prioritized defect reports directly in the WECAVIS web portal, maintaining human-in-the-loop oversight over all AI-generated assessments.