Building Regulations set strict energy efficiency requirements for every new dwelling. SAP 10.3, and its replacement HEM, assign punitive default ψ-values to every junction unless a bespoke calculation proves otherwise. Modern details routinely beat these defaults by 80–97%. Without proof, your assessor must use the defaults. Your fabric energy efficiency fails. You are forced into expensive upgrades, or worse, a building that cannot comply.
Psiclops calculates your actual ψ-values, U-values, and condensation risk, and produces the BR 497 report your SAP assessor needs, signed by you or verified by a qualified architect.
Psiclops also provides a comprehensive U-value and Glaser condensation check for any assembly, always free, with no account needed. Your first ψ-value calculation is free too.
Reports, AI improvements, and ψ-value calculations need a free account.
SAP 10.3 and HEM enforce conservative defaults wherever a bespoke calculation has not been submitted. This affects both junctions and assemblies, and the penalties are severe.
SAP 10.3 Table K1 assigns a punitive default ψ-value to every junction type unless a bespoke BR 497 calculation is provided. A modern insulated lintel detail that should carry ψ = 0.027 W/(m·K) is instead charged 1.000, 37 times worse. Across 10–20 junctions in a typical dwelling, this alone can make the difference between passing and failing fabric energy efficiency.
BR 443 simplified U-value methods cannot handle bridged constructions — a timber stud or joist running through insulation — without accounting for the bridging using ISO 6946:2017's own combined method, which Psiclops applies automatically. More complex bridging geometries, like I-joist panels or metal web joists, need a full 2D finite element analysis instead. Psiclops calculates the real U-value either way — by manual layer description for straightforward bridging, or by DXF for complex geometries the combined method itself can't accurately resolve.
A Glaser analysis checks whether water vapour will condense within your assembly at the design condition. Failing Glaser does not always mean the construction is wrong, but it does mean the design needs to be reconsidered or evidence provided. Psiclops runs Glaser automatically with every U-value calculation, free of charge, so you know before you build.
Upload a DXF drawn in any CAD tool to provide exact junction or assembly geometry. This includes all junction types as well as more complex assemblies that simplified bridging methods can't resolve, like I-joist panels or metal web joists, for full finite element analysis.
Our AI helps match material descriptions to published thermal conductivity values, flagging anything unverified — you always confirm or override before calculation. No λ-value lookup tables required.
A finite element solver based on EN ISO 10211 calculates the temperature field, heat flux, and ψ-value for your exact geometry. Not an approximation, the actual calculation the standard requires.
Every junction is checked against BR 497's own validity rules as it's calculated, not just written up in the right format afterwards. The report carries an AI-generated narrative describing your junction's thermal performance. Self-sign as competent person, or request architect verification.
After every U-value or Glaser check, Psiclops can analyse your assembly and suggest specific changes to improve thermal performance or resolve condensation risk, such as repositioning the vapour control layer, increasing insulation continuity, or switching to a higher-performing product. Concrete, actionable suggestions based on your actual build-up, not generic guidance.
Most tools stop at producing a document in the right format. Psiclops goes further: every junction is checked against BR 497's own validity rules as it's calculated, and if something falls short, it's flagged directly in the report, not silently passed through. Your SAP assessor gets a calculation that's been tested, not just formatted, with an AI-written narrative describing the junction geometry and its thermal performance.
Flanking element lengths are checked against BR 497's stated minimums for every junction. Any that fall short are flagged in the report, not silently accepted.
Party-wall and party-floor junctions get BR 497 §4.4.3's required ψ-value halving applied automatically and cited in the report, not left for the assessor to catch.
If you are a competent person under SAP 10.3 Route 3, a structural engineer, energy consultant, or suitably qualified practitioner, you can sign the report yourself. Psiclops captures your competent person declaration once at the project level and carries it through to every report.
The FEM solver is validated against EN ISO 10211 reference cases, so the mathematics is independently verified. What the architect confirms is different: that the DXF geometry, the assigned materials, and the processed cross-section shown in the report are a credible representation of the architectural detail as submitted. They review the submitted DXF, the materials list, and the calculation output as documented, confirming the report accurately reflects the provided inputs. They are not re-running the calculation or inspecting the building.
No subscription required. A 15-junction house should not cost 15 times more than a single-junction calculation, so it does not. Free where it should be free, fair where it costs.
No card required. No subscription to cancel. U-value and Glaser checks are always free. Upload your first DXF and see whether your detail actually beats the SAP default before you commit to anything.