# Handover — post Slices S0380.146..149 Branch: `feature/per-cert-mapper-validation`. **HEAD `35ea664d`**. Predecessor: [`HANDOVER_POST_S0380_147.md`](HANDOVER_POST_S0380_147.md). ## TL;DR Four slices landed on top of `1636cfbc` (the predecessor handover commit). The session closed the **oil cohort Table 4f auxiliary energy gap**: oil 1 SAP +2.66 → **+0.40**, oil pcdb 3 SAP +1.16 → **+0.39**, pcdb 1 +0.57 → +0.50, oil pcdb 1/2 +0.42 → +0.36. Cascade HW fuel cascade is now exact at the worksheet line ref for oil 1 (3638.99 kWh/yr). The session also **applied spec-correct dispatch uniformly across the entire cohort** per the user's mid-session directive ([[feedback-software-no-special-handling]]): "The software doesn't have special non-spec handling." This unmasked offsetting cascade gaps that the pre-fix `_DEFAULT_PUMPS_FANS_KWH_PER_YR = 130` and `_PUMPS_FANS_KWH_BY_MAIN_CATEGORY[2] = 160` hardcodes had been masking — solid fuel 2 regressed +2.64 → +3.15, electric storage cohort moved from ~zero to +0.45..+0.66 SAP, etc. | Slice | Commit | Scope | |---|---|---| | S0380.146 | `bd193e06` | SAP 10.2 Table 3 row 1 — primary loss for Table 4b non-PCDB regular boilers + cylinder. New `_TABLE_4B_COMBI_OR_CPSU_CODES` zero-loss exclusion set. | | S0380.147 | `7dceeff2` | SAP 10.2 Appendix D §D2.1 (2) Eq D1 — wire monthly winter/summer cascade for non-PCDB Table 4b boilers. New `tables/table_4b.py` carries 41-row (winter, summer) dict verbatim from spec p.168. `_apply_water_efficiency` refactored to `eq_d1_winter_summer_pct: Optional[tuple[float, float]]`. | | S0380.148 | `1b1f45b6` | SAP 10.2 Table 4f "Liquid fuel boiler – flue fan and fuel pump" 100 kWh/yr — added for Main 1 + Main 2 per Note c). New `is_liquid_fuel_code` in `tables/table_32.py`. | | **S0380.149** | **`35ea664d`** | **SAP 10.2 Table 4f circulation pump per pump age (41 / 165 / 115) + new `_is_wet_boiler_main` gate (Table 4a/4b code 101-141/151-161/191-196 + PCDB Table 322 + cat {1,2} fallback). Removes `_PUMPS_FANS_KWH_BY_MAIN_CATEGORY` + `_DEFAULT_PUMPS_FANS_KWH_PER_YR`. Mapper fix: "2012 or earlier" → int 1 (was silently 2).** | Extended handover suite at HEAD: **892 pass, 0 fail.** Pyright net-zero / net-improved. ## Critical user directive (read first) **[[feedback-software-no-special-handling]]**: "The software doesn't have special non-spec handling." The BRE-approved Elmhurst lodging software follows spec exactly. When a spec-correct fix shifts a cohort cert pin, the pre-fix near-zero state was masking offsetting cascade gaps — NOT a deliberate non-spec rule. Apply spec uniformly + re-pin + document the unmasked gap as a follow-up. S0380.147 was initially scoped narrowly ("only fire Eq D1 when cylinder is present") to avoid shifting cert 0240/6035. The user pushed back; the cylinder gate was removed; cert 0240/6035 were re-pinned. Same discipline applies to S0380.149's broader cohort shift. ## Current residual state at HEAD `35ea664d` ### Cascade-OK tier (25 variants on pin grid) — sorted by |ΔSAP_c| | Variant | SAP code | ΔSAP_c | Δcost | ΔPE | Notes | |---|---:|---:|---:|---:|---| | ashp | 214 | +0.24 | -£5.57 | -12 | (closed) | | oil pcdb 1/2 | (PCDB) | +0.36 | -£8.32 | -67 | | | oil pcdb 3 | (PCDB) | +0.39 | -£8.91 | -67 | | | oil 1 | 127 | +0.40 | -£9.31 | -71 | | | solid fuel 4 | 633 | +0.45 | -£10.42 | -107 | room heater | | electric 1 | 191 | +0.45 | -£10.42 | -40 | electric boiler | | electric 8 | 409 | +0.49 | -£11.23 | -71 | | | solid fuel 11 | 634 | +0.48 | -£11.08 | -92 | room heater | | pcdb 1 | (PCDB) | +0.50 | -£11.10 | -93 | | | electric 7 | 408 | +0.54 | -£12.44 | -84 | | | solid fuel 6 | 160 | +0.54 | -£12.39 | -90 | | | solid fuel 9 | 636 | +0.55 | -£12.64 | -104 | room heater | | electric 6 | 404 | +0.57 | -£13.24 | -93 | | | solid fuel 10 | 634 | +0.58 | -£13.45 | -130 | room heater | | solid fuel 7 | 160 | +0.60 | -£14.07 | -118 | | | electric 9 | 421 | +0.63 | -£14.43 | -105 | | | electric 3 | 401 | +0.66 | -£15.13 | -115 | | | electric 5 | 402 | -0.68 | +£15.70 | +339 | regressed by .145 | | gshp | 211 | +1.15 | -£26.48 | -455 | open | | solid fuel 3 | 160 | +1.83 | -£42.19 | -1069 | PE outlier | | solid fuel 2 | 158 | +3.15 | -£72.53 | -1346 | PE outlier (regressed by .149) | | solid fuel 5 | 153 | +0.34 | -£7.93 | -42 | | | solid fuel 8 | 160 | +0.43 | -£9.89 | -89 | | | electric 2 | 524 | -0.18 | +£4.24 | +393 | warm-air ASHP | | solid fuel 4 | 633 | +0.45 | -£10.42 | -107 | room heater | Σ |ΔSAP_c| across 25 variants ≈ **15.4 SAP points** (was 10.7 pre- session — Note: appearance of "regression" is misleading because the pre-session pins on solid fuel + electric were masking offsetting bugs via the 130 kWh default. The new pins reflect the actual underlying cascade-vs-worksheet gap.) ### Blocked tier (16 variants — `MissingMainFuelType`) Unchanged from previous handover. Categories: community heating × 5, electric storage 11-14, no system, oil 2-6, pcdb 3. ## Pattern observed across the cohort After S0380.149's spec-correct dispatch, MANY variants share a **~-£10 to -£14 cost residual** (cascade UNDER worksheet by ~£10-14). This is a cohort-wide signal: there's a systematic gap somewhere producing ~£10/yr of cost the cascade is missing. Candidates: - **Space heating fuel kWh under-count**: cascade SH useful kWh tends to be slightly above worksheet (e.g. oil 1 +87 kWh useful = +103 fuel = +£5.60 cost), but the cost residual is -£10 (cascade UNDER). So SH fuel isn't the driver of the under-count. - **A possible (45) energy content or (62) HW demand under-count**. - **Standing charges** (Table 12 footnote) — cascade may not be including off-peak / gas standing charges that the worksheet adds. - **Table 4f component I'm still missing** — keep-hot facility (600 kWh combi gas), warm-air heating fans (SFP × 0.4 × V), or solar HW pump on certs with solar. This is the **next-slice front**: identify the cohort-wide cost deficit and close it. ## Next-slice candidates ranked by leverage ### 1. **Cohort-wide ~-£10/yr cost under-count** — highest leverage Affects ~15+ variants simultaneously. Probe a variant with high fidelity (oil 1, oil pcdb 1) line-by-line against the worksheet (240) SH cost / (247) HW cost / (249) pumps cost / (250) lighting cost / (251) standing charges → total (255). One of these line refs is under-counting. ### 2. **solid fuel 2 +3.15 / 3 +1.83 PE outliers** — anthracite Both Table 4a codes 158/160. PE residuals -1346 / -1069 kWh/yr are huge. Likely Table 4b solid-fuel efficiency, Table 4f, or §9 anthracite-specific secondary fraction. ### 3. **electric 5 -0.68** — still open from S0380.145 regression Pre-S0380.145 was +0.07 (offsetting bugs). Post-slice with +0.4 K Table 4e adjustment applied: cascade now OVER worksheet SH by ~248 kWh. Likely §9 MIT calc for fan-assisted storage heater R=0.40 (code 402) OR Table 9b Tsc formula divergence. ### 4. **gshp +1.15** — heat pump cascade PCDB Table 362 dispatch. Separate from the boiler cohort. ### 5. **Community heating unblocking (5 variants)** — extractor work Extend extractor to capture §14.1 Community Heating block (heat- network codes 41-58). ### 6. **Electric storage unblocking (variants 11-14)** Extend `_ELMHURST_MAIN_HEATING_EES_TO_FUEL_CODE` for EES codes WEA, REA, OEA. ### 7. **Cert 0240 dual-main Q_space split** Cert 0240 has main_heating_fraction = 51%/49%. Spec Eq D1 says Q_space = (98c)m × (204) per Main 1's fraction. Cascade currently uses full (98c)m. Closing this might close the +£11 cost gap on cert 0240 too. ## Important diagnostic findings from this session 1. **Cohort-wide spec correctness exposes the underlying cascade gaps**. Pre-fix near-zero pins on solid fuel / electric were coincidental — the broken 130 kWh default cancelled real cascade gaps. Now that the pumps_fans dispatch is spec-correct, the cascade-vs-worksheet diff is visible for the first time. 2. **Pre-existing default fallbacks are landmines**. The 130 kWh and 160 kWh hardcodes silently mis-classified ~25 cohort variants — each shift looked like a regression but was actually the truth becoming visible. 3. **PCDB-listed certs need a separate wet-boiler discriminator**. `sap_main_heating_code` is None on PCDB-listed mains; the `_is_wet_boiler_main` helper had to add a Table 322 lookup to correctly identify them as wet. 4. **The "next oil property" pattern**: focus on closing one variant at a time, but the spec fix typically applies cohort-wide. Two slices (one spec rule each) closed five oil variants together. ## 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 (DO NOT widen tolerance) 6. Run extended handover suite (command below) 7. Pyright net-zero check (`git stash` → pyright → `git stash pop` → pyright; or stripping line numbers from diff to find genuinely new errors after a refactor) 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 `35ea664d` ```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: **892 pass, 0 fail**. ## Memories to load (in order) ``` project-heating-systems-corpus # HEAD 35ea664d feedback-sap-10-2-only-never-10-3 # CRITICAL — never reference SAP 10.3 feedback-software-no-special-handling # CRITICAL — apply spec uniformly, no empirical gates feedback-worksheet-not-api-reference feedback-spec-citation-in-commits feedback-verify-handover-claims feedback-zero-error-strict # TARGET: ΔSAP_c < 1e-4 vs worksheet 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** — re-pin smaller or find the spec gap - **Don't add empirical gates** to keep cohort pins stable when a spec rule clearly applies. The cohort-wide ~-£10 cost shift after S0380.149 is NOT a regression — it's spec correctness unmasking offsetting bugs. Don't reintroduce the 130 default to "fix" it. - **Don't re-investigate Slices .91..149** — all settled - **Don't add new helpers to `domain/sap10_ml/`** — on deprecation path; `domain/sap10_calculator/tables/` is the canonical home - **Don't treat ΔSAP=0.07 as "closed"** — target is <1e-4 vs worksheet ## 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) - **§9** (p.155+) — MIT calc, Tables 9/9a/9b/9c - **§9.4.11** (p.30) — Boiler interlock: -5pp to BOTH SH and DHW - **§A.2.2** (~p.189) — Forced-secondary set - **Table 3** (p.160) — Primary circuit loss; zero-loss list - **Table 4a** (p.163-170) — heating systems incl. R column - **Table 4b** (p.168) — gas/liquid boilers seasonal efficiency - **Table 4c** (p.169-170) — Efficiency adjustments - **Table 4d** (p.170) — heat-emitter R - **Table 4e** (p.170-173) — heating system controls + temp adjustment - **Table 4f** (p.174) — pumps + fans (S0380.148..149 territory) - **Table 9c** (p.184) — heating requirement (step 8 Table 4e adj) - **Table 11** (p.188) — secondary heating fraction - **Table 12** (p.191) — SAP rating fuel prices + standing charges - **Table 12a** (p.191) — high/low-rate fraction by system × tariff - **Appendix D §D2.1 (2)** (p.57) — Eq D1 monthly water eff cascade - **RdSAP 10 spec**: `RdSAP 10 Specification 10-06-2025.pdf` - **§10.11 Table 29** (p.56) — Heating/HW parameters; inaccessible cylinder - **§19 Table 32** (p.95) — RdSAP10 fuel prices / CO2 / PE ## Good luck.