Under what conditions can cavity, partially cavity-based and cavity-free external wall systems provide safe, durable and resilient building-envelope performance — and what evidence is required to demonstrate those functions over the intended service life?
A completed 43-page evidence review — External Wall Design in a Changing UK Climate — examining regulation, warranty standards, official fire investigations, peer-reviewed building physics, international field records and UK climate projections. Principal findings carried with the report's own verdicts; areas the evidence does not reach recorded honestly as INSUFFICIENT EVIDENCE.
Investigation 001
External publication, Issue 02, August 2026 · Lead researcher and report author: Luke Smith · Briefing film published on YouTube; full written report released and available on the investigation page.