Every change to Psiclops that affects what a calculation actually produces, or how a result is presented — in plain language, dated, and tagged with the exact engine build it resulted in. That build number is the same one shown in your own report's Software and Standards “Modules” line, so you can confirm exactly which version of Psiclops computed a specific figure. See calculation verification for live, re-runnable checks against published reference values.
Two independent issues were found and fixed. First: the annual interstitial condensation check for 2D assemblies and junctions could treat any locally supersaturated point in the mesh as its own independent condensation plane, rather than restricting this to genuine material interfaces the way EN ISO 13788's own method does. Cross-validated directly against the standard's own certified Annex C.5 worked example, this was found to overstate peak accumulated moisture by up to ~60x for a real, non-extreme construction, and could report a fail where the correct result is a pass. Second: the external design temperature used for junction and assembly modelling is corrected from an unverified -5°C to 0°C — BR 497's own explicitly stated convention ("the usual temperatures to use when modelling"). Per BR 497, this does not change any previously-calculated ψ-value or fRsi verdict, but does change reported heat-flow figures and the design temperature shown on affected reports.
The worst (least-margin) point on an interstitial condensation plot is now labelled with the material(s) it sits on or between — e.g. "interface: OSB/3 ↔ Insulated I-Joist bay" — instead of an unlabelled marker with no construction context. Applied to the live results page and the internal calculation-verification suite.
The 2D interstitial condensation check introduced two days earlier was cross-validated directly against the classic 1D Glaser method for an identical flat construction, where both should agree exactly. Two real bugs were found and fixed: a numerical-precision issue that could silently return zero vapour flow, and the check reusing a different standard's surface resistance convention (BRE IP1/06's Rsi=0.25) in place of Glaser's own EN ISO 13788 convention (Rsi=0.13).
A new check for 2D DXF-derived assemblies and junctions: a second finite element solve using each material's vapour resistivity in place of thermal conductivity, comparing the resulting vapour-pressure field against saturation pressure across the full 2D cross-section rather than at fixed 1D layer interfaces — able to catch a risk location, such as a thermal bridge, that a 1D method has no way to represent. Available for both assemblies and junctions.
Junctions flagged as party-wall details now have their declared ψ-value correctly halved against the full party-element length, with the pre-halving figure retained and shown alongside it, and the relevant BR 497 clause cited directly in the generated report.
The SAP Table K1 junction-type classifier was substantially reworked to use real geometric signals from the drawn junction plus an explicit plan/section hint, with an AI fallback and a confirmation step before any classification is accepted. Separately, a direct audit against BR 497 found and corrected four discrepancies: the internal surface resistance convention wasn't being applied directionally where BR 497 requires it, an unheated space wasn't being modelled as fully exposed to the external environment as the standard requires, a fRsi/condensation corner-singularity case needed relaxing, and fRsi reporting precision was corrected.
Added a "Show FEM mesh" toggle to the results page, letting you see the actual solver triangulation as a QA check. Also corrected the Software and Standards citations for the U-value, ψ-value, and fRsi checks to be sourced directly from the modules that actually compute them, rather than a separately-maintained copy that had drifted out of sync — including a casing fix for fRsi and its BRE IP1/06 caption.
Introduced per-module version tracking for the calculation engine, shown as a single combined build number on the landing page and itemised in full in every generated report's own Software and Standards section. Also corrected which standard is cited for surface and interstitial condensation checks (BRE IP1/06, not BR 497), and thermal plots gained the ability to trace real material-polygon boundaries over a solved field.
Covers changes since per-module version tracking began (13 July 2026). Development started 24 June 2026; earlier changes aren't individually listed here since no per-module version signal existed yet to tag them against.