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+# PasHub extractor accuracy — handover (2026-07-14 late)
+
+## Goal
+Guinness GMCA 205-property cohort within 0.5 SAP of pashub's `pre_sap`
+(PRD #1555). Khalim: "We can get to 100% within 0.5 for this cohort." The
+bugs are **extraction** (survey detail not reaching the calculator), not the
+calculator — proven repeatedly this session.
+
+## Where we are (branch `feat/pashub-extractor-fixes-and-runner`, pushed)
+Harness `backend/documents_parser/tests/test_pashub_sap_accuracy.py`:
+**205/205 compute, MAE 1.551, within-0.5 18.5% (38/205), bias ≈ −1.0**
+(from 12.4%/2.56 at session start). Ratchets `_MIN_WITHIN_HALF=0.18`,
+`_MAX_SAP_MAE=1.56` — tighten after every fix, comment each move.
+
+### Fixed this session (all TDD 🟥/🟩 pairs; see git log on the branch)
+Issue **#1590** (all 7 subtasks done + 2 round-2 fixes; trajectory table in
+its last comment): secondary fuel labels; Table 4e Group 3 control 2306;
+roof "Insulation At: None"→explicit 0; **PV arrays extracted+mapped**
+(`_pashub_pv_arrays`); `pv_connection`→int (1/2); **mechanical ventilation**
+`_pashub_mechanical_ventilation_kind` (biggest win: 76 fixtures, MAE −0.8);
+cylinder size Table 28; system-build/basement code-6 collision;
+**room-in-roof** (survey `RoomInRoofDetail` → extractor `_parse_room_in_roof`
+→ mapper `_pashub_room_in_roof`; commons are `stud_wall`, roof-space
+insulation threads into slope/stud/flat surfaces); **community heating**
+(extractor captures "Heating System (Other):" → `_pashub_community_heating`
+→ `sap_main_heating_code=301` + Table 12 fuel 51 via
+`_resolve_community_heating_fuel_code`).
+
+Issue **#1589** (separate, unfixed): modelling `refetch_epc=True` violates
+ADR-0001 recency — gov API overrides newer stored site notes.
+
+## Ground truth — now verified
+`pre_sap` in the manifest was hand-verified by Khalim in pashub for the 4
+worst deviations (2026-07-14): manifest corrected for 499584755922 (F33, was
+stale D67 — we were right) and 499617935574 (accredited E43, was preliminary
+53). **Confirmed correct** (so our deviation = extraction bug to hunt):
+
+| deal | address | pashub | ours | d |
+|---|---|---|---|---|
+| 499530733767 | 58 Hackle Street, M11 4WU | D58 | 65.8 | **+7.8** |
+| 499617935574 | Brightholme, 14 North Road, M11 4WE | 43 | 50.3 | **+7.3** |
+| 507644414148 | 16 Bingley Close, M11 3RF | E52 | 57.7 | **+5.7** |
+
+Rule: don't tune to `pre_sap` blindly, but after this verification treat it
+as trustworthy unless a survey PDF plainly contradicts it (then ask Khalim to
+check pashub — give him the ADDRESS, not the deal id).
+
+## The proven working loop (repeat until 100%)
+1. Rank divergences: parse every manifest fixture (`parse_site_notes_pdf` →
+   `Sap10Calculator().calculate`) vs `pre_sap_score`; list worst signed.
+2. Fan out 3-5 Sonnet sub-agents, one per worst case, with THE RECIPE:
+   dump extracted `EpcPropertyData` fields; dump PDF text (`fitz`); diff
+   field-by-field against the survey; attribute via `dataclasses.replace`
+   patch-and-rerun (record SAP delta per candidate fix); report the
+   mis-extracted field + concrete fix + deltas. Investigation only, no edits.
+3. TDD each confirmed fix (`/tdd` skill): RED commit 🟥 → GREEN commit 🟩,
+   test in `datatypes/epc/domain/tests/test_from_site_notes.py` (mapper) and/or
+   `backend/documents_parser/tests/test_extractor.py` (extractor; splice
+   verbatim PDF lines into `load_text_fixture()`); update the golden
+   `test_full_mapping` when field coding changes.
+4. Re-run harness; ratchet; commit; push.
+
+## Conventions (non-negotiable)
+- `_pashub_*` helpers strict-raise `UnmappedPasHubLabel` on unknown non-empty
+  labels; blank passes through/None. Mirror `_ELMHURST_*`/`_api_*` siblings.
+- pyright: zero NEW errors (baselines: mapper.py 39, extractor.py 34,
+  test_from_site_notes.py ≤13). Beware `Union[RoofSpaceDetail,
+  ExtensionRoofSpace]` attribute access — add fields to BOTH.
+- Survey dataclasses hold RAW labels; coding happens at the mapper boundary
+  (ADR-0015). Ratchets never loosen at fixed coverage.
+
+## Known leads for the remaining gap
+- **Solid ground floors**: worst-biased category (n=107, mean −1.53; 5/7 of
+  the −4..−5 Natural-ventilation cluster: 499529160912, 499538003156,
+  499627236560, 499586692333, 507533541571, 499570197710, 499592219845).
+  Dig the ISO 13370 solid-floor U/perimeter cascade vs what the surveys lodge.
+- 16 Bingley (+5.7): community-heating residual — water heating is
+  "Hot water only community scheme - boilers" (WHC 950 path?), community
+  standing charge/tariff detail, or DLF "Unknown" distribution type.
+- 58 Hackle (+7.8): undug — full recipe pass needed.
+- Brightholme (+7.3): RIR dwelling; the accredited 43 reflects a QA
+  correction ("no access to loft — hatch screwed shut") — possibly RIR
+  insulation should NOT thread from the roof-space block when access was
+  impossible, or slopes should default worse. Check `_pashub_room_in_roof`.
+- Mechanical ventilation and PCDB efficiency are VERIFIED CORRECT — don't re-dig.
+
+## Also outstanding
+- **Open the review PR** for the branch (metrics table = #1590's last
+  comment; ~26 commits, all green: 206 harness + ~294 unit tests).
+- Portfolio 838 modelling: re-extract 4 properties in pashub (754772/9
+  Philips Park Court, 754780/12 Seymour Rd S, 754844/16 Bingley — the
+  community fix now makes it extractable, 754816/130 Stanton St has no site
+  note at all); then `RUN_DRY=0 python scripts/run_pashub_modelling.py`
+  (env-parametrised: RUN_PORTFOLIO/RUN_SCENARIO/RUN_PIDS/RUN_DRY).
+- `effective_sap_score` == the pashub rating for unchanged lodged dwellings
+  (rebaseliner pass-through) — NEVER validate the calculator against it.
+- hubspot_deal_data still holds the stale pre_sap for the 2 corrected deals —
+  re-running `scripts/build_pashub_accuracy_fixtures.py` will REVERT the
+  manifest corrections unless the DB rows are fixed first.