Slice 19a: strict cascade-pin scoreboard for SapResult vs U985 PDFs

Replaces the loose collection of fixture-specific SAP score tests +
parametrized lighting / pumps_fans / secondary spot-checks with a
single strict cascade pin: every SapResult float field vs PDF line
ref at abs=1e-4, every fixture × field pair as its own parametrized
case. 66 cases (11 fields × 6 fixtures); 18 pass, 48 fail.

Why: the Elmhurst corpus is a deterministic test-vector set — input
lodgement, intermediate values per line ref, final SAP outputs all
known to 4 d.p. To replicate SAP 10.2 exactly there is no reason to
accept tolerance >0 on the final outputs. The prior pattern (per-
section unit tests using PDF values as INPUTS, fixture-specific SAP
tests at <=0.5 continuous, fuel-cost tests at rel=0.05 / rel=0.15)
let cascade biases propagate without surfacing as named failures.

Pin matrix:

  field                              | 474 | 477 | 480 | 487 | 490 | 516
  -----------------------------------|-----|-----|-----|-----|-----|-----
  sap_score (int)                    |  ✓  |  ✓  |  ✓  |  ✗  |  ✓  |  ✓
  sap_score_continuous               |  ✗  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  ecf                                |  ✗  |  ✗  |  ✓  |  ✗  |  ✗  |  ✗
  total_fuel_cost_gbp                |  ✗  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  co2_kg_per_yr                      |  ✗  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  space_heating_kwh_per_yr           |  ✗  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  main_heating_fuel_kwh_per_yr       |  ✗  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  secondary_heating_fuel_kwh_per_yr  |  ✓  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  hot_water_kwh_per_yr               |  ✗  |  ✗  |  ✗  |  ✗  |  ✗  |  ✗
  lighting_kwh_per_yr                |  ✓  |  ✓  |  ✓  |  ✓  |  ✓  |  ✗
  pumps_fans_kwh_per_yr              |  ✓  |  ✓  |  ✓  |  ✓  |  ✓  |  ✓

Each failing test name is the work queue. No tolerance widening, no
xfail — a failing pin is a named calculator bug. Subsequent slices
close them one at a time.

Existing loose-tolerance tests in test_fuel_cost.py (rel=0.15 for
000474 and rel=0.05 for 000490) are subsumed by the new
total_fuel_cost_gbp pin at abs=1e-4 and will be removed in 19b.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

packages/domain/src/domain/sap/worksheet/tests/test_e2e_elmhurst_sap_score.py

@@ -1,31 +1,38 @@
-"""End-to-end SAP score validation against the Elmhurst worksheet outputs.
+"""End-to-end cascade pins against the Elmhurst U985 worksheet PDFs.
 
-For each non-RR Elmhurst fixture, run the full calculator chain
+The Elmhurst corpus is a deterministic test-vector set: each cert has
-    EpcPropertyData → cert_to_inputs → calculate_sap_from_inputs
+input lodgement (the Summary_NNNNNN PDF), intermediate values per
-and compare the resulting SAP score against the Elmhurst worksheet's
+line ref (the U985-0001-NNNNNN PDF), and final SAP outputs (the
-SAP rating (line 258).
+rating section). To replicate the SAP 10.2 engine exactly we pin
+every SAP-result field against the PDF at `abs=1e-4` for every
+fixture in the cohort.
 
-These tests pin the current end-to-end gap so subsequent slices that
+Each pin is its own test case via pytest parametrize so failures are
-shrink it (worksheet §4 wired into cert_to_inputs, PCDB Table 3b combi
+named like `test_sap_result_pin[000487-main_heating_fuel_kwh_per_yr]`
-loss, etc.) show up as tolerance tightening rather than silent drift.
+— making the work queue legible.
 
-Reference: Elmhurst U985-0001-000474.pdf and U985-0001-000490.pdf
+Per `[[feedback-e2e-validation-philosophy]]` + `[[feedback-continuous-
-(supplied by the user; not stored in repo).
+sap-tolerance]]`: tolerances are NOT widened to mask drift. A failing
+pin is a named calculator bug to fix, not a tolerance to relax.
+
+Reference: SAP 10.2 specification (14-03-2025).
 """
 
-from dataclasses import dataclass
+from dataclasses import dataclass, fields
+from types import ModuleType
 from typing import Final
 
 import pytest
 
-from types import ModuleType
-
 from domain.sap.calculator import Sap10Calculator
 from domain.sap.rdsap.cert_to_inputs import cert_to_inputs
 from domain.sap.worksheet.tests import (
     _elmhurst_worksheet_000474 as _w000474,
     _elmhurst_worksheet_000477 as _w000477,
+    _elmhurst_worksheet_000480 as _w000480,
+    _elmhurst_worksheet_000487 as _w000487,
     _elmhurst_worksheet_000490 as _w000490,
+    _elmhurst_worksheet_000516 as _w000516,
 )
 from domain.sap.worksheet.tests._elmhurst_fixtures import (
     ALL_FIXTURES as _ELMHURST_FIXTURES,
@@ -33,301 +40,158 @@ from domain.sap.worksheet.tests._elmhurst_fixtures import (
 )
 
 
+# Absolute tolerance for every float field — matches the PDF's 4 d.p.
+# display precision. Anything closer is sub-spec resolution; anything
+# looser is a drift gap.
+_FLOAT_PIN_ABS: Final[float] = 1e-4
+
+
 @dataclass(frozen=True)
-class ElmhurstExpectedSap:
+class FixtureCascadePins:
-    """Headline figures from the Elmhurst worksheet's SAP rating section
+    """PDF-extracted expected values for every top-level `SapResult`
-    (xlsx rows around line refs 240 / 255 / 257 / 258 / 261)."""
+    field. Each value is the canonical line ref from the U985 worksheet
-
+    (page references in the field comments). Field names mirror
-    sap_rating: int                # (258) integer
+    `SapResult` exactly so the parametrized test can read both via
-    sap_score_continuous: float    # (258) un-rounded
+    `getattr` without per-field plumbing.
-    space_heating_kwh: float       # (98c) annual
-    hot_water_kwh: float           # (219) annual fuel
-    total_energy_cost_gbp: float   # (255)
-    ecf: float                     # (257)
-
-
-_ELMHURST_000490_EXPECTED: Final[ElmhurstExpectedSap] = ElmhurstExpectedSap(
-    sap_rating=57,
-    sap_score_continuous=57.3979,
-    space_heating_kwh=11183.2751,
-    hot_water_kwh=2850.5701,
-    total_energy_cost_gbp=807.5421,
-    ecf=3.0539,
-)
-_ELMHURST_000477_EXPECTED: Final[ElmhurstExpectedSap] = ElmhurstExpectedSap(
-    sap_rating=65,
-    sap_score_continuous=65.0050,
-    space_heating_kwh=10111.2019,
-    hot_water_kwh=2116.0365,
-    total_energy_cost_gbp=732.1396,
-    ecf=2.5086,
-)
-_ELMHURST_000474_EXPECTED: Final[ElmhurstExpectedSap] = ElmhurstExpectedSap(
-    sap_rating=62,
-    sap_score_continuous=62.2584,
-    space_heating_kwh=10612.8595,
-    hot_water_kwh=2291.7784,
-    total_energy_cost_gbp=655.6949,
-    ecf=2.7055,
-)
-
-
-def test_elmhurst_000477_end_to_end_sap_score_matches_pdf() -> None:
-    """Cohort closure pin for 000477. Mid-terrace combi-gas with PCDF
-    Vaillant ecoTEC sustain 24 (index 18118) + Electricity Electric
-    Panel secondary heater (SAP code 691). PDF SAP rating 65."""
-    # Arrange
-    epc = _w000477.build_epc()
-
-    # Act
-    result = Sap10Calculator().calculate(epc)
-
-    # Assert — integer match (the rdsap engine integration gate).
-    delta = abs(result.sap_score - _ELMHURST_000477_EXPECTED.sap_rating)
-    assert delta == 0, (
-        f"SAP rating delta {delta} — expected 0 (integer match with PDF). "
-        f"Actual={result.sap_score}, expected={_ELMHURST_000477_EXPECTED.sap_rating}."
-    )
-    continuous_delta = abs(
-        result.sap_score_continuous - _ELMHURST_000477_EXPECTED.sap_score_continuous
-    )
-    assert continuous_delta <= 0.5, (
-        f"Continuous SAP delta {continuous_delta:.2f} exceeds ceiling 0.5"
-    )
-
-
-def test_elmhurst_000490_end_to_end_sap_score_currently_within_3_points() -> None:
-    """Mid-terrace combi-gas dwelling with time-clock keep-hot. After the
-    PCDB Table 105 integration the fixture lodges `main_heating_index_
-    number=10328` (Vaillant Ecotec Pro 28kW, winter eff 88.2%, summer
-    79.6%) per the PDF's "PCDF boiler reference: 10328 Vaillant Ecotec
-    Pro 88.20%" lodgement. Cert path now resolves efficiency via the
-    spec-faithful PCDB precedence rather than the Table 4a category-2
-    default (80%).
-
-    Post-PCDB residuals:
-
-    | metric          | actual   | PDF       | delta |
-    | --------------- | -------- | --------- | ----- |
-    | space heating   | 11467.18 | 11183.275 | +2.5% |
-    | hot water fuel  |  3028.27 |  2850.570 | +6.2% |
-    | main heating fuel | 13001.3| 13003.85  | -0.02%|
-    | total fuel cost | £706.23  | £807.54   | −12.5%|
-    | SAP rating      | 63       | 57        | +6    |
-
-    The PCDB efficiency override closes the main-heating-fuel gap to <0.1%
-    (matches PDF), and the HW kWh gap narrows from +8.4% → +6.2%. The
-    total fuel cost diverges from -6.3% → -12.5% and the SAP score moves
-    +3 → +6 because the lodged cert pre-dates the 14-March-2025 SAP10.2
-    amendment which lowered gas unit prices ~13% (per ADR-0010 §3
-    Validation Cohort: only certs lodged ≥2025-07-01 are spec-comparable
-    on cost / SAP rating). The fuel-kWh tightening is the spec-faithful
-    direction; the cost / SAP residuals are documented spec-version
-    drift, not a calculator regression.
-
-    Ceiling raised 3 → 6 (SAP integer) and 3.0 → 6.0 (continuous) to
-    reflect the post-PCDB current state. **§10a slice 2 tightening:**
-    ceiling dropped 6 → 2 after the cost-side rewrite (Table 32 prices
-    + Table 12 note (a) standing-charge gating per ADR-0010 amendment)
-    landed. The "spec-version drift" framing in the handover turned out
-    to be wrong-table + missing-standing-charges — a real calculator
-    regression, not a corpus issue. **§4 HW slice 2 update:** ceiling
-    raised 2 → 3 because the Equation D1 monthly cascade closes the HW
-    kWh gap (3028 → 2847 = 0.1% of PDF 2851), which slightly *reduces*
-    cost (£776 → £770) and pushes SAP score from 59 → 60 — further
-    from the spec-version-drifted PDF SAP 57. The HW kWh closure is
-    the spec-faithful direction; the +3 SAP delta is the ADR-0010 §3
-    Validation Cohort filter at work. Tightens further when Tables
-    D1/D2/D3 Ecodesign + Appendix N adjustments land.
     """
-    # Arrange
-    epc = _w000490.build_epc()
 
-    # Act
+    sap_score: int                         # (258) integer rating
-    result = Sap10Calculator().calculate(epc)
+    sap_score_continuous: float            # (258) un-rounded
-
+    ecf: float                             # (257) energy cost factor
-    # Assert — full cohort residual hunt closed: Appendix L lighting +
+    total_fuel_cost_gbp: float             # (255) total energy cost
-    # secondary heating cascade + ventilation cert lodgements + Table 4f
+    co2_kg_per_yr: float                   # (272) total CO2 emissions
-    # pumps_fans + SAP 10.2 rating constants. 000490 now hits SAP integer
+    space_heating_kwh_per_yr: float        # (98c) annual space heat
-    # delta=0 (continuous ~0.002 under PDF).
+    main_heating_fuel_kwh_per_yr: float    # (211) main system 1 fuel
-    delta = abs(result.sap_score - _ELMHURST_000490_EXPECTED.sap_rating)
+    secondary_heating_fuel_kwh_per_yr: float  # (215) secondary fuel
-    assert delta == 0, (
+    hot_water_kwh_per_yr: float            # (219) water heating fuel
-        f"SAP rating delta {delta} — expected 0 (integer match with PDF). "
+    lighting_kwh_per_yr: float             # (232) electricity for lighting
-        f"Actual={result.sap_score}, expected={_ELMHURST_000490_EXPECTED.sap_rating}."
+    pumps_fans_kwh_per_yr: float           # (231) pumps + fans + flue
-    )
-    continuous_delta = abs(
-        result.sap_score_continuous - _ELMHURST_000490_EXPECTED.sap_score_continuous
-    )
-    assert continuous_delta <= 0.5, (
-        f"Continuous SAP delta {continuous_delta:.2f} exceeds ceiling 0.5"
-    )
 
 
-def test_elmhurst_000474_end_to_end_sap_score_currently_within_3_points() -> None:
+_FIXTURE_PINS: Final[dict[str, FixtureCascadePins]] = {
-    """End-terrace PCDB-tested Vaillant boiler. After the PCDB Table 105
+    "000474": FixtureCascadePins(
-    integration the fixture lodges `main_heating_index_number=16839`
+        sap_score=62, sap_score_continuous=62.2584, ecf=2.7055,
-    (Vaillant ecoTEC pro 28 VUW GB 286/5-3, winter eff 88.7%, summer
+        total_fuel_cost_gbp=655.6949, co2_kg_per_yr=3036.2933,
-    87.0%, comparative HW 75.1%) per the PDF's "PCDF boiler reference:
+        space_heating_kwh_per_yr=10612.8595,
-    16839 Vaillant ecoTEC pro 28 88.70%" lodgement.
+        main_heating_fuel_kwh_per_yr=11964.8924,
+        secondary_heating_fuel_kwh_per_yr=0.0,
+        hot_water_kwh_per_yr=2291.7784,
+        lighting_kwh_per_yr=139.9452,
+        pumps_fans_kwh_per_yr=160.0,
+    ),
+    "000477": FixtureCascadePins(
+        sap_score=65, sap_score_continuous=65.0057, ecf=2.5086,
+        total_fuel_cost_gbp=732.1396, co2_kg_per_yr=2807.8621,
+        space_heating_kwh_per_yr=10111.2019,
+        main_heating_fuel_kwh_per_yr=10270.9726,
+        secondary_heating_fuel_kwh_per_yr=1011.1202,
+        hot_water_kwh_per_yr=2116.0365,
+        lighting_kwh_per_yr=201.6754,
+        pumps_fans_kwh_per_yr=160.0,
+    ),
+    "000480": FixtureCascadePins(
+        sap_score=61, sap_score_continuous=61.2986, ecf=2.7743,
+        total_fuel_cost_gbp=854.8139, co2_kg_per_yr=3393.8852,
+        space_heating_kwh_per_yr=12398.5783,
+        main_heating_fuel_kwh_per_yr=12580.2936,
+        secondary_heating_fuel_kwh_per_yr=1239.8578,
+        hot_water_kwh_per_yr=2423.6393,
+        lighting_kwh_per_yr=212.5531,
+        pumps_fans_kwh_per_yr=160.0,
+    ),
+    "000487": FixtureCascadePins(
+        sap_score=62, sap_score_continuous=61.6431, ecf=2.7496,
+        total_fuel_cost_gbp=828.6119, co2_kg_per_yr=2931.4900,
+        space_heating_kwh_per_yr=10834.7778,
+        main_heating_fuel_kwh_per_yr=11018.4181,
+        secondary_heating_fuel_kwh_per_yr=1083.4778,
+        hot_water_kwh_per_yr=1489.1033,
+        lighting_kwh_per_yr=227.6861,
+        pumps_fans_kwh_per_yr=160.0,
+    ),
+    "000490": FixtureCascadePins(
+        sap_score=57, sap_score_continuous=57.3979, ecf=3.0539,
+        total_fuel_cost_gbp=807.5421, co2_kg_per_yr=3213.5359,
+        space_heating_kwh_per_yr=11183.2751,
+        main_heating_fuel_kwh_per_yr=11411.5052,
+        secondary_heating_fuel_kwh_per_yr=1118.3275,
+        hot_water_kwh_per_yr=2850.5701,
+        lighting_kwh_per_yr=171.4217,
+        pumps_fans_kwh_per_yr=160.0,
+    ),
+    "000516": FixtureCascadePins(
+        sap_score=63, sap_score_continuous=62.7937, ecf=2.6671,
+        total_fuel_cost_gbp=860.7162, co2_kg_per_yr=3416.8449,
+        space_heating_kwh_per_yr=12410.3170,
+        main_heating_fuel_kwh_per_yr=12606.4169,
+        secondary_heating_fuel_kwh_per_yr=1241.0317,
+        hot_water_kwh_per_yr=2493.1900,
+        lighting_kwh_per_yr=230.8853,
+        pumps_fans_kwh_per_yr=160.0,
+    ),
+}
 
-    Post-PCDB residuals — nearly closed:
 
-    | metric          | actual  | expected | delta |
+_FIXTURE_MODULES: Final[dict[str, ModuleType]] = {
-    | --------------- | ------- | -------- | ----- |
+    "000474": _w000474,
-    | space heating   | 10914.3 | 10612.86 | +2.8% |
+    "000477": _w000477,
-    | hot water fuel  |  2621.7 |  2291.78 | +14.4%|
+    "000480": _w000480,
-    | total fuel cost | £651.85 | £655.69  | -0.6% |
+    "000487": _w000487,
-    | SAP rating      | 63      | 62       | +1    |
+    "000490": _w000490,
+    "000516": _w000516,
+}
 
-    The PCDB summer efficiency override (was 80% → 87.0%) closes the HW
-    fuel gap from +32% to +14.4% — the residual is the Appendix J §3b
-    PCDB combi loss table that our HW cascade still uses Table 3a row
-    defaults for. The SAP rating sits comfortably within tolerance.
 
-    Ceiling dropped 7 → 2 (SAP integer) and 7.0 → 2.0 (continuous)
+_PIN_FIELDS: Final[tuple[str, ...]] = tuple(f.name for f in fields(FixtureCascadePins))
-    reflecting the post-PCDB current state. **§10a slice 2 update:**
-    ceiling raised 2 → 4 because the post-§10a Table 32 + standing-
-    charge rewrite exposed upstream HW kWh + Appendix L lighting kWh
-    overestimates that the wrong pre-§10a prices had been masking.
-    **§4 HW slices 1 + 2 update:** ceiling dropped 4 → 3 — PCDB Table
-    3b combi-loss override + Equation D1 monthly water-eff cascade
-    close 000474 HW kWh from 2622 → 2292 (matches PDF 2292 to ≤0.1%).
-    The remaining +9% cost residual and +3 SAP delta are Appendix L
-    lighting (528 vs ~169 back-derived) — a separate ticket per memory
-    `project_section_4_hw_next_ticket`'s "secondary upstream" note.
-    """
-    # Arrange
-    epc = _w000474.build_epc()
-
-    # Act
-    result = Sap10Calculator().calculate(epc)
-
-    # Assert — Appendix L closure brought 000474 SAP integer to 62 = PDF 62
-    # (delta = 0 exactly). Continuous delta lands at ~0.09 — well under the
-    # 0.5 ceiling. Per feedback-e2e-validation-philosophy: integer match
-    # is the rdsap engine integration gate; this fixture now passes that gate.
-    delta = abs(result.sap_score - _ELMHURST_000474_EXPECTED.sap_rating)
-    assert delta == 0, (
-        f"SAP rating delta {delta} — expected 0 (integer match with PDF). "
-        f"Actual={result.sap_score}, expected={_ELMHURST_000474_EXPECTED.sap_rating}."
-    )
-    continuous_delta = abs(
-        result.sap_score_continuous - _ELMHURST_000474_EXPECTED.sap_score_continuous
-    )
-    assert continuous_delta <= 0.5, (
-        f"Continuous SAP delta {continuous_delta:.2f} exceeds ceiling 0.5"
-    )
 
 
 @pytest.mark.parametrize(
-    "fixture, expected_kwh",
+    "fixture_name,field_name",
-    [
+    [(name, fld) for name in _FIXTURE_PINS for fld in _PIN_FIELDS],
-        (_w000474, _w000474.LINE_232_LIGHTING_KWH_PER_YR),
+    ids=lambda x: x,
-        (_w000490, _w000490.LINE_232_LIGHTING_KWH_PER_YR),
-    ],
-    ids=["000474", "000490"],
 )
-def test_elmhurst_end_to_end_lighting_kwh_per_yr_matches_u985_worksheet(
+def test_sap_result_pin(fixture_name: str, field_name: str) -> None:
-    fixture: object, expected_kwh: float
+    """Strict cascade pin — `SapResult.<field>` matches the U985 PDF's
-) -> None:
+    line ref to abs=1e-4 for every fixture × field combination.
-    """Component-level e2e validation: `SapResult.lighting_kwh_per_yr`
-    must match the U985 worksheet's line ref (232) value to 4 d.p. for
-    each fixture lodged with full Appendix L cert inputs.
 
-    Closes the legacy `predicted_lighting_kwh` heuristic — the cost-side
+    Each (fixture, field) pair is its own pytest case so failures
-    annual kWh is now derived via the same spec-faithful L1-L11 cascade
+    surface as `test_sap_result_pin[000487-main_heating_fuel_kwh_per_yr]`
-    that drives §5 (67). Per ADR-0010 + the e2e validation philosophy
+    — the work queue is the test list. Per validation philosophy:
-    (memory: feedback-e2e-validation-philosophy) — component pins
+    no tolerance widening, no xfail; a failing pin is a calculator
-    validate the rdsap engine piece by piece; SAP integer integration
+    bug to fix.
-    test must hit delta=0 in a later cycle.
     """
     # Arrange
-    epc = fixture.build_epc()  # type: ignore[attr-defined]
+    pin = _FIXTURE_PINS[fixture_name]
+    epc = _FIXTURE_MODULES[fixture_name].build_epc()
+    expected = getattr(pin, field_name)
 
     # Act
     result = Sap10Calculator().calculate(epc)
+    actual = getattr(result, field_name)
 
     # Assert
-    assert result.lighting_kwh_per_yr == pytest.approx(expected_kwh, abs=1e-4)
+    if isinstance(expected, int):
-
+        assert actual == expected, (
-
+            f"{fixture_name}.{field_name}: actual={actual}, expected={expected}"
-@pytest.mark.parametrize(
+        )
-    "fixture, expected_kwh",
+    else:
-    [
+        assert actual == pytest.approx(expected, abs=_FLOAT_PIN_ABS), (
-        (_w000474, 160.0),
+            f"{fixture_name}.{field_name}: actual={actual}, "
-        (_w000490, 160.0),
+            f"expected={expected}, diff={abs(actual - expected):.4f}"
-    ],
+        )
-    ids=["000474", "000490"],
-)
-def test_elmhurst_end_to_end_pumps_fans_kwh_matches_u985_worksheet(
-    fixture: object, expected_kwh: float
-) -> None:
-    """Component-level pin on `SapResult.pumps_fans_kwh_per_yr` for the
-    e2e fixtures. PDF (231) for both 000474 + 000490: 115 (central
-    heating pump (230c)) + 45 (main heating flue fan (230e)) = 160.
-
-    Pre-fix `cert_to_inputs` hardcoded 130 kWh/yr via
-    `_DEFAULT_PUMPS_FANS_KWH_PER_YR`. The shortfall (-30 kWh × elec
-    price = -£4) was the dominant remaining residual on 000490 after
-    Appendix L + secondary heating + ventilation closures — pushed
-    continuous SAP +0.38 over PDF → integer 58 vs 57.
-    """
-    # Arrange
-    epc = fixture.build_epc()  # type: ignore[attr-defined]
-
-    # Act
-    result = Sap10Calculator().calculate(epc)
-
-    # Assert
-    assert result.pumps_fans_kwh_per_yr == pytest.approx(expected_kwh, abs=1e-3)
-
-
-def test_elmhurst_000490_end_to_end_secondary_heating_fuel_kwh_matches_u985_worksheet() -> None:
-    """Component-level e2e pin on `SapResult.secondary_heating_fuel_kwh_per_yr`
-    for 000490 — cert lodges secondary heating system "Electricity Electric
-    Panel, convector or radiant heaters" (SAP Code 691, 100% efficiency).
-    Table 11 fraction 0.10 of total space heat goes to the secondary
-    system → (215) = 1118.3275 kWh.
-
-    Closes the next 000490 residual after Appendix L: secondary fuel was
-    silently 0 because build_epc didn't lodge secondary_heating_type, so
-    `_secondary_fraction` early-returned 0.0 → all useful space heat
-    routed to main 1 → main_fuel_kwh +1357 kWh over PDF, secondary -1118
-    under PDF. Cost gap was £147 secondary missing minus £47 main
-    overshoot = -£104 (the dominant residual after Appendix L closure).
-    """
-    # Arrange
-    epc = _w000490.build_epc()
-
-    # Act
-    result = Sap10Calculator().calculate(epc)
-
-    # Assert — useful space heating now matches PDF to ~0.01% (post
-    # ventilation-cert closures); secondary cascade propagates 1:1 →
-    # residual ≤ 0.1 kWh.
-    assert result.secondary_heating_fuel_kwh_per_yr == pytest.approx(
-        _w000490.LINE_215_SECONDARY_HEATING_FUEL_KWH, abs=0.1
-    )
 
 
 @pytest.mark.parametrize("fixture", _ELMHURST_FIXTURES, ids=_elmhurst_fixture_id)
 def test_elmhurst_cert_to_inputs_monthly_infiltration_ach_matches_u985_worksheet(
     fixture: ModuleType,
 ) -> None:
-    """Component-level pin on `cert_to_inputs(epc).monthly_infiltration_ach`
+    """Cert→inputs (25)m effective ACH pin (existing test, retained).
-    for every Elmhurst fixture. The cert→inputs path must produce the same
-    (25)m effective ACH tuple that the §2 ventilation module test pins
-    against `LINE_25_EFFECTIVE_ACH`.
 
-    Pre-fix the cert path under-counted (8) openings (extract_fans_count
+    Each fixture's `monthly_infiltration_ach` from `cert_to_inputs` must
-    defaulted to 0; PDF lodges 1-2) AND over-counted (15) window infil
+    match the U985 worksheet's LINE_25_EFFECTIVE_ACH at abs=1e-3 — the
-    (percent_draughtproofed defaulted to 0; PDF lodges 75-100). The net
+    upstream of `_sap_result_pin`'s heat-loss-rate path. Lives outside
-    bias on (25)m propagates 1:1 to HLC × ΔT → useful space heat → main
+    the cascade-pin grid because it asserts an intermediate (cert→
-    + secondary fuel kWh → cost / SAP integer.
+    inputs) value, not a SAP result field.
-
-    Once this pin lands the only remaining ventilation-cascade gap is
-    `sheltered_sides` (not on EPC schema; cert_to_inputs hardcodes 2 —
-    addressed in the next cycle).
     """
     # Arrange
     epc = fixture.build_epc()
@@ -340,24 +204,3 @@ def test_elmhurst_cert_to_inputs_monthly_infiltration_ach_matches_u985_worksheet
         assert inputs.monthly_infiltration_ach[m] == pytest.approx(
             fixture.LINE_25_EFFECTIVE_ACH[m], abs=1e-3
         ), f"(25) month {m+1} drift"
-
-
-def test_elmhurst_000490_end_to_end_kwh_within_15pct() -> None:
-    """Per-end-use kWh sanity check for 000490. Closer-fitting than the
-    SAP score because intermediate values aren't compressed through the
-    cost-deflator + rating equations."""
-    # Arrange
-    epc = _w000490.build_epc()
-
-    # Act
-    result = Sap10Calculator().calculate(epc)
-
-    # Assert
-    exp = _ELMHURST_000490_EXPECTED
-    assert result.space_heating_kwh_per_yr == pytest.approx(
-        exp.space_heating_kwh, rel=0.15
-    )
-    assert result.hot_water_kwh_per_yr == pytest.approx(exp.hot_water_kwh, rel=0.15)
-    assert result.total_fuel_cost_gbp == pytest.approx(
-        exp.total_energy_cost_gbp, rel=0.15
-    )