Thread appliances + cooking annual kWh onto SapResult for ADR-0014 bills

ADR-0014 BillDerivation prices a per-end-use EnergyBreakdown
(HEATING / HOT_WATER / LIGHTING / PUMPS_FANS / APPLIANCES / COOKING).
SapResult already carried the first four but not appliances or cooking,
so a downstream SapResult→EnergyBreakdown adapter had to stub those two
at 0 kWh — understating the bill by the whole unregulated electricity
load. Surface them so the property_baseline side can wire the sections.

Adds two output-only fields to CalculatorInputs + SapResult, threaded
exactly like lighting_kwh_per_yr:
  appliances_kwh_per_yr  — SAP 10.2 Appendix L L13/L14/L16a annual E_A
                           (sum of the §5 (68) monthly appliances kWh)
  cooking_kwh_per_yr     — SAP 10.2 Appendix L L20 (p.91) ELECTRICITY
                           estimate E_cook = 138 + 28×N

Both values already existed in cert_to_inputs.py (appliances_monthly_kwh,
cooking_monthly_kwh) — reused, not recomputed.

Fuel attribution: cooking_kwh_per_yr is the L20 ELECTRICITY figure (the
field docstring says so), distinct from the L18 cooking heat GAIN
(35 + 7N W) the §5 internal-gains cascade uses. The bill adapter should
treat cooking as an electricity carrier; a gas-cooker split, if ever
needed, is a separate follow-up.

HARD CONSTRAINT honoured — output-only, zero rating drift. Appliances +
cooking are unregulated and are NOT fed into ECF / total_fuel_cost /
CO2 / primary energy / sap_score. Every golden-fixture, Elmhurst e2e
SapResult pin, section cascade pin, and heating-corpus residual stays
byte-identical (1165 rated pins green). The synthetic CalculatorInputs
fixtures set the new fields non-zero on purpose so the existing cost/PE
reconciliation assertions act as leak detectors.

New focused test asserts both fields are populated (non-zero) and
threaded unchanged onto SapResult, with cooking equal to the L20
electricity figure (138 + 28×occupancy) to 1e-9. pyright net-zero
111 → 111.

Note: 11 pre-existing failures in test_appendix_u.py / test_table_32.py
arrived with the recently absorbed PR and are unrelated to this change
(they fail identically on the clean branch); flagged separately.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

domain/sap10_calculator/calculator.py

@@ -178,6 +178,14 @@ class CalculatorInputs:
     hot_water_kwh_per_yr: float
     pumps_fans_kwh_per_yr: float
     lighting_kwh_per_yr: float
+    # Unregulated annual delivered electricity — output-only, NOT fed
+    # into ECF / cost / CO2 / primary energy / sap_score (regulated
+    # energy only). Surfaced for ADR-0014 BillDerivation's APPLIANCES +
+    # COOKING sections. `cooking_kwh_per_yr` is the SAP 10.2 Appendix L
+    # L20 (p.91) ELECTRICITY figure (138 + 28×N), not the L18 cooking
+    # heat gain. `appliances_kwh_per_yr` is the L13/L14/L16a annual E_A.
+    appliances_kwh_per_yr: float
+    cooking_kwh_per_yr: float
     space_heating_fuel_cost_gbp_per_kwh: float
     hot_water_fuel_cost_gbp_per_kwh: float
     other_fuel_cost_gbp_per_kwh: float
@@ -357,6 +365,15 @@ class SapResult:
     hot_water_kwh_per_yr: float
     pumps_fans_kwh_per_yr: float
     lighting_kwh_per_yr: float
+    # Unregulated annual delivered electricity for ADR-0014
+    # BillDerivation (APPLIANCES + COOKING sections). Output-only — these
+    # do NOT contribute to ecf / total_fuel_cost_gbp / co2_kg_per_yr /
+    # primary_energy_kwh_per_yr / sap_score. `cooking_kwh_per_yr` is the
+    # SAP 10.2 Appendix L L20 (p.91) ELECTRICITY estimate (138 + 28×N);
+    # the bill adapter should treat it as an electricity carrier (a
+    # gas-cooker split, if ever needed, is a separate follow-up).
+    appliances_kwh_per_yr: float
+    cooking_kwh_per_yr: float
     primary_energy_kwh_per_yr: float
     primary_energy_kwh_per_m2: float
     monthly: tuple[MonthlyEntry, ...]
@@ -745,6 +762,8 @@ def calculate_sap_from_inputs(inputs: CalculatorInputs) -> SapResult:
         hot_water_kwh_per_yr=inputs.hot_water_kwh_per_yr,
         pumps_fans_kwh_per_yr=inputs.pumps_fans_kwh_per_yr,
         lighting_kwh_per_yr=inputs.lighting_kwh_per_yr,
+        appliances_kwh_per_yr=inputs.appliances_kwh_per_yr,
+        cooking_kwh_per_yr=inputs.cooking_kwh_per_yr,
         primary_energy_kwh_per_yr=primary_energy_kwh,
         primary_energy_kwh_per_m2=primary_energy_per_m2,
         monthly=monthly,

domain/sap10_calculator/rdsap/cert_to_inputs.py

@@ -6163,6 +6163,13 @@ def cert_to_inputs(
         hot_water_kwh_per_yr=hw_kwh,
         pumps_fans_kwh_per_yr=pumps_fans_kwh,
         lighting_kwh_per_yr=lighting_kwh,
+        # Unregulated annual delivered electricity for ADR-0014
+        # BillDerivation — output-only, NOT wired into cost / CO2 / PE.
+        # Appliances: SAP 10.2 Appendix L L13/L14/L16a (sum of the §5
+        # (68) monthly E_A). Cooking: Appendix L L20 (p.91) ELECTRICITY
+        # E_cook = 138 + 28×N, already summed in `cooking_monthly_kwh`.
+        appliances_kwh_per_yr=sum(appliances_monthly_kwh),
+        cooking_kwh_per_yr=sum(cooking_monthly_kwh),
         space_heating_fuel_cost_gbp_per_kwh=_space_heating_fuel_cost_gbp_per_kwh(
             main, _rdsap_tariff(epc), prices
         ),

domain/sap10_calculator/tests/test_bre_worked_examples.py

@@ -115,6 +115,11 @@ def _baseline_dwelling() -> CalculatorInputs:
         hot_water_kwh_per_yr=2400.0,
         pumps_fans_kwh_per_yr=100.0,
         lighting_kwh_per_yr=600.0,
+        # Non-zero on purpose: unregulated loads that must NOT leak into
+        # cost / CO2 / PE / sap_score (the reconciliation assertions sum
+        # only the regulated end-uses, so a leak would surface here).
+        appliances_kwh_per_yr=2000.0,
+        cooking_kwh_per_yr=200.0,
         space_heating_fuel_cost_gbp_per_kwh=0.07,
         hot_water_fuel_cost_gbp_per_kwh=0.07,
         other_fuel_cost_gbp_per_kwh=0.07,

domain/sap10_calculator/tests/test_calculator.py

@@ -119,6 +119,11 @@ def _baseline_inputs() -> CalculatorInputs:
         hot_water_kwh_per_yr=2400.0,
         pumps_fans_kwh_per_yr=100.0,
         lighting_kwh_per_yr=600.0,
+        # Non-zero on purpose: these unregulated loads must NOT leak into
+        # cost / CO2 / PE / sap_score. The reconciliation assertions in
+        # this file sum only the regulated end-uses, so a leak surfaces here.
+        appliances_kwh_per_yr=2000.0,
+        cooking_kwh_per_yr=200.0,
         space_heating_fuel_cost_gbp_per_kwh=0.07,
         hot_water_fuel_cost_gbp_per_kwh=0.07,
         other_fuel_cost_gbp_per_kwh=0.07,

domain/sap10_calculator/worksheet/tests/test_e2e_elmhurst_sap_score.py

@@ -25,7 +25,10 @@ from typing import Final
 import pytest
 
 from domain.sap10_calculator.calculator import Sap10Calculator
-from domain.sap10_calculator.rdsap.cert_to_inputs import cert_to_inputs
+from domain.sap10_calculator.rdsap.cert_to_inputs import (
+    cert_to_inputs,
+    water_heating_section_from_cert,
+)
 from domain.sap10_calculator.worksheet.tests import (
     _elmhurst_worksheet_000474 as _w000474,
     _elmhurst_worksheet_000477 as _w000477,
@@ -220,3 +223,36 @@ 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_appliances_and_cooking_kwh_threaded_onto_sap_result() -> None:
+    """Appliances + cooking annual delivered electricity reach SapResult.
+
+    ADR-0014 BillDerivation prices an APPLIANCES and a COOKING section,
+    so the unregulated electricity loads the rating cascade already
+    computes must be surfaced on SapResult (previously a downstream
+    adapter stubbed them at 0 kWh, understating the bill). Cooking is
+    the SAP 10.2 Appendix L L20 (p.91) ELECTRICITY estimate E_cook =
+    138 + 28 × N (N = assumed occupancy) — distinct from the L18 cooking
+    heat GAIN (35 + 7N W) the §5 internal-gains cascade uses. Appliances
+    is the L13/L14/L16a annual E_A distributed monthly.
+    """
+    # Arrange — a normal main-only gas-combi cert (non-zero TFA → non-
+    # zero appliances + cooking).
+    fixture = _FIXTURE_MODULES['000516']
+    epc = fixture.build_epc()
+    water_heating = water_heating_section_from_cert(epc)
+    assert water_heating is not None  # 000516 has a TFA, so HW is present
+    expected_cooking_kwh = 138.0 + 28.0 * water_heating.occupancy  # Appendix L L20
+
+    # Act
+    inputs = cert_to_inputs(epc)
+    result = Sap10Calculator().calculate(epc)
+
+    # Assert — both fields populated and threaded unchanged from
+    # CalculatorInputs onto SapResult; cooking equals the L20 electricity
+    # figure (NOT the larger L18 gain) to 1e-9.
+    assert inputs.appliances_kwh_per_yr > 0.0
+    assert result.appliances_kwh_per_yr == inputs.appliances_kwh_per_yr
+    assert result.cooking_kwh_per_yr == inputs.cooking_kwh_per_yr
+    assert abs(result.cooking_kwh_per_yr - expected_cooking_kwh) <= 1e-9

tests/domain/property_baseline/test_calculator_rebaseliner.py

@@ -47,6 +47,8 @@ def _sap_result(
         hot_water_kwh_per_yr=0.0,
         pumps_fans_kwh_per_yr=0.0,
         lighting_kwh_per_yr=0.0,
+        appliances_kwh_per_yr=0.0,
+        cooking_kwh_per_yr=0.0,
         primary_energy_kwh_per_yr=0.0,
         primary_energy_kwh_per_m2=primary_energy_kwh_per_m2,
         monthly=(),