Session shipped 5 slices that closed the entire cohort-2 API-path
cluster (S0380.39 bulk-fetch, S0380.40 parametrized test, S0380.41
RdSAP 21 → SAP 10.2 glazing alias, S0380.42 Decimal HALF_UP per-window
areas, S0380.43 SAP 631 → spec fuel).
Documents:
- Cross-mapper parity at cascade established for all 38 cohort-2
certs (and 9 cohort-1 ASHP); both paths < 1e-4 vs worksheet.
- Tolerance tightening deferred — 1e-4 is the realistic floor at
HEAD (worst residual 4.91e-5 on cert 2102).
- Lessons learned: GOV.UK RdSAP 21 enum != cascade enum (codes
needing remap are incremental as fixtures surface them);
Decimal HALF_UP per-window areas extends the S0380.34/35
pattern; SAP heating-type → spec fuel dispatch is the new
forcing-function pattern for cert-lodgement inconsistencies.
- Open front: golden-residuals → ~0 on PE/CO2. ASHP cluster
(-7..-15 kWh/m² PE / +0.16..+0.28 t/yr CO2 across 7 certs with
the same PCDB heat pump) is the highest-value single thread —
likely SAP 10.2 Appendix L1 / Table 12 PE-factor or CO2-factor
cascade gap. Three concrete diagnostic probes proposed.
Test baseline at HEAD: 750 pass + 0 fail.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
