# Handover — post Slices S0380.141..143 Branch: `feature/per-cert-mapper-validation`. **HEAD `eda6f449`**. Predecessor: [`HANDOVER_POST_S0380_140.md`](HANDOVER_POST_S0380_140.md). ## TL;DR Three slices landed on top of `8ee877e4` this session, all concentrated on the §4 / §9.4.11 cascade for **PCDB regular oil boilers feeding a cylinder** (cert pcdb 1 in the heating-systems corpus). Each slice surfaced 1-2 spec-citable bugs hidden behind silent fallbacks; together they closed pcdb 1 from SAP +6.95 to +0.57 (-92% magnitude). | Slice | Commit | Scope | |---|---|---| | **S0380.141** | `6636f1c3` | SAP 10.2 §9.4.11 (PDF p.30) "Boiler interlock": -5pp adjustment now applies to BOTH space-heating efficiency and the PCDB Equation D1 monthly water cascade (previously only the `water_eff` scalar fallback got the adjustment). SH path further gated on `pcdb_main is not None` so cert 000565 (ASHP Main 1) is unaffected. | | **S0380.142** | `7f9074fc` | SAP 10.2 §4 line 7702 + Table 3 cylinder-presence gates: (a) combi loss = 0 whenever `epc.has_hot_water_cylinder` is True (combi boilers are by definition instantaneous per Table 3 zero-loss list); (b) `_primary_loss_applies` returns True when `main_heating_index_number` resolves to a PCDB Table 322 (gas/oil boiler) record. Golden cert 0390-2954-3640-2196-4175 re-pinned (PE -26.37 → -28.50, CO2 -2.55 → -2.75) because primary-loss gain (~5-10 kWh) < combi-loss removal (-600 kWh). | | **S0380.143** | `eda6f449` | RdSAP 10 §10.11 Table 29 (PDF p.56) "Hot water cylinder insulation if not accessible" — new `_resolve_elmhurst_inaccessible_cylinder_insulation(age_band)` helper deriving `(insulation_type, thickness_mm)` from construction age band when §15.1 lodges "Cylinder Size: No Access". Age G/H → 25 mm foam (code 1); I-M → 38 mm foam (code 1); A-F raises `UnmappedElmhurstLabel` (loose-jacket SAP10 enum not yet exercised). | Extended handover suite at HEAD: **886 pass, 0 fail.** ## Current residual state at HEAD `eda6f449` ### Cascade-OK tier (25 variants on pin grid) | Variant | ΔSAP_c | Δcost | ΔPE | Notes | |---|---:|---:|---:|---| | ashp | +0.24 | -£5.57 | -12 | closed | | electric 1 | -0.06 | +£1.32 | +94 | | | electric 2 | +0.47 | -£10.92 | +101 | warm-air ASHP | | **electric 3** | **+2.55** | **-£58.65** | **-1122** | open | | electric 5 | +0.07 | -£1.72 | -161 | | | **electric 6** | **+1.33** | **-£30.60** | **-563** | open | | **electric 7** | **+1.29** | **-£29.73** | **-498** | open | | electric 8 | -0.26 | +£5.92 | +126 | | | electric 9 | -0.12 | +£2.72 | +91 | | | gshp | +1.15 | -£26.48 | -455 | | | **oil 1** | **+2.66** | **-£61.24** | **-1050** | open | | oil pcdb 1/2 | +0.42 | -£9.77 | -84 | closed | | oil pcdb 3 | +1.16 | -£26.72 | -271 | | | **pcdb 1** | **+0.57** | **-£12.55** | **-109** | closed via S0380.141..143 (was +6.95 / -£157.61 / -3135 PE) | | **solid fuel 2** | **+2.64** | **-£60.79** | **-1211** | PE outlier | | **solid fuel 3** | **+1.32** | **-£30.45** | **-935** | PE outlier | | solid fuel 4-11 (×8) | -0.29..+0.10 | small | ±170 | | ### Blocked tier (16 variants) Unchanged from previous handover — community heating × 5, electric storage 11/12/13/14, no system, oil 2-6, pcdb 3. ## Next-slice candidates ranked by leverage ### 1. **electric 3 / 6 / 7 SAP +1.3..+2.5 (cluster of 3)** — open Surfaced by S0380.139. Cascade `_secondary_heating_fraction_for_ category` defaults to 0.10 when mapper leaves `main_heating_category=None`; worksheet for SAP code 401/402 uses 0.15 (Table 11 Cat 7 "electric storage"). Mapper-side fix: derive `main_heating_category` from SAP code when not lodged. Side issue: code 408 (HHR storage) is in `_FORCE_SECONDARY_FOR_MAIN_CODES` but spec docstring says forced applies to "401 to 407, 409 and 421" only — 408 excluded. The previous +2.5 SAP cluster (electric 3, oil 1, solid fuel 2) was diagnosed as HETEROGENEOUS during S0380.140 work. Electric 3's driver is §9 MIT for storage heaters; oil 1's is HW efficiency for non-PCDB Table 4b oil boilers; solid fuel 2's is HW lodging in a different line ref. The shared "+2.5 SAP" magnitude is coincidence, not signal. Per-variant slices still recommended. ### 2. **oil 1 SAP +2.66 / cost -£61 / PE -1050** — open Table 4b oil boiler (code 127, eff 84%) with cylinder lodged + Boiler Interlock: Yes (per cert). The -5pp interlock fix from S0380.141 does NOT apply (interlock is present). Cascade HW kWh 2785 vs worksheet 3639. Worksheet effective HW efficiency ≈ 65% suggests summer/winter blend the cascade may not be applying for non-PCDB oil boilers per SAP 10.2 Appendix D §D2.1. ### 3. **solid fuel 2 / 3 PE -935..-1211** — open Both anthracite (codes 158, 160). Same fuel + R as variants that closed. Distinct cause from #1 above. Per-variant probe required. ### 4. **community heating unblocking (5 variants)** — sizeable Extend extractor to capture §14.1 Community Heating block (heat-network codes 41-58). Each cert maps to a Table 32 heat-network code via the lodged heat source type. ### 5. **Electric storage unblocking (variants 11-14)** — small Extend `_ELMHURST_MAIN_HEATING_EES_TO_FUEL_CODE` for EES codes WEA, REA, OEA. ## What's still open on pcdb 1 (~SAP +0.57) The residual ~+0.57 SAP is primarily a ~1.3% cascade-side undercount on space-heating demand (cascade SH 7900 kWh vs worksheet (98c) 8004 kWh). This is a §8 driver — different MIT or gains calculation between cascade and worksheet. Falls within "spec-cascade floor" noise; not chasable without a clearer probe target. ## Standard slice workflow 1. Read spec page + identify rule 2. Probe one cluster variant; verify diagnosis via monkey-patch 3. Write failing AAA test (literal `# Arrange / # Act / # Assert`) 4. Implement helper / dispatch entry / mapper extension 5. Re-pin affected variants 6. Run extended handover suite (command in previous handover) 7. Pyright net-zero check (`git stash` → pyright → `git stash pop` → pyright) 8. Commit with spec citation + `Co-Authored-By: Claude Opus 4.7 ` 9. Update `project-heating-systems-corpus` + `MEMORY.md` index ## Test baseline at HEAD `eda6f449` ```bash PYTHONPATH=/workspaces/model python -m pytest \ backend/documents_parser/tests/test_summary_pdf_mapper_chain.py \ backend/documents_parser/tests/test_heating_systems_corpus.py \ backend/documents_parser/tests/test_elmhurst_extractor.py \ backend/documents_parser/tests/test_elmhurst_end_to_end.py \ domain/sap10_calculator/worksheet/tests/test_e2e_elmhurst_sap_score.py \ domain/sap10_calculator/worksheet/tests/test_heat_transmission.py \ domain/sap10_calculator/worksheet/tests/test_internal_gains.py \ domain/sap10_calculator/worksheet/tests/test_solar_gains.py \ domain/sap10_calculator/worksheet/tests/test_dimensions.py \ domain/sap10_calculator/worksheet/tests/test_rating.py \ domain/sap10_calculator/worksheet/tests/test_ventilation.py \ domain/sap10_calculator/worksheet/tests/test_appendix_h_solar.py \ domain/sap10_calculator/worksheet/tests/test_mev.py \ domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py \ domain/sap10_calculator/rdsap/tests/test_golden_fixtures.py \ domain/sap10_calculator/tests/test_pcdb_table_322_lookup.py \ domain/sap10_calculator/tests/test_pcdb_table_329_lookup.py \ domain/sap10_calculator/tests/test_table_12a.py \ --no-cov -q ``` Expected: **886 pass, 0 fail**. ## Memories to load (in order) ``` project-heating-systems-corpus # HEAD eda6f449 feedback-sap-10-2-only-never-10-3 # CRITICAL — never reference SAP 10.3 feedback-worksheet-not-api-reference feedback-spec-citation-in-commits feedback-verify-handover-claims feedback-zero-error-strict feedback-commit-per-slice feedback-aaa-test-convention feedback-e2e-validation-philosophy feedback-abs-diff-over-pytest-approx feedback-spec-floor-skepticism feedback-golden-residuals-near-zero feedback-one-e-minus-4-across-the-board reference-unmapped-sap-code reference-unmapped-api-code project-oil-price-spec-divergence ``` ## What NOT to do - **Don't reference SAP 10.3** — track 10.2 deliberately - **Don't widen pin tolerances** to make pins pass — re-pin smaller or find the spec gap - **Don't re-investigate Slices .91..143** — all settled - **Don't add new helpers to `domain/sap10_ml/`** — on deprecation path ## Spec source quick-reference All under `domain/sap10_calculator/docs/specs/`: - **SAP 10.2 full spec**: `sap-10-2-full-specification-2025-03-14.pdf` - **§4** (p.135-137) — water heating worksheet (45..65), Tables 2/2a/2b - **§9** (p.155+) — MIT calc, Tables 9/9a/9b - **§9.4.11** (p.30) — Boiler interlock: -5pp to BOTH SH and DHW - **Table 3** (p.160) — Primary circuit loss; zero-loss list - **Table 4a/4b/4c/4d** — heating systems + responsiveness + interlock - **Table 4f** (p.174) — pumps + fans - **Table 11** — secondary heating fraction by category - **Table 12** (p.191) — SAP rating fuel prices - **Table 12a** (p.191) — high/low-rate fraction by system × tariff - **RdSAP 10 spec**: `RdSAP 10 Specification 10-06-2025.pdf` - **§10.11 Table 29** (p.56) — Heating and hot water parameters; inaccessible cylinder defaults - **§19 Table 32** (p.95) — RdSAP10 fuel prices / CO2 / PE ## Good luck.