Lock the sloping-ceiling override's U-value end-to-end (col-3 as-built, col-1a by depth) 🟩

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/domain/epc/test_roof_type_overlay.py

@@ -12,6 +12,28 @@ import pytest
 from datatypes.epc.domain.epc_property_data import BuildingPartIdentifier
 from domain.epc.property_overlays.roof_type_overlay import roof_overlay_for
 from domain.epc.property_overrides.roof_type import RoofType
+from domain.sap10_ml.rdsap_uvalues import Country, u_roof
+
+
+def _resolved_roof_u(roof_type_value: str, age_band: str) -> float:
+    """Score a resolved roof override through the real `u_roof`, deriving the
+    sloping-ceiling flag exactly as the calculator does from the overlay's
+    `roof_construction_type` string (`heat_transmission.py`:
+    `is_pitched_sloping_ceiling = "sloping ceiling" in roof_type_lower`). This
+    ties the overlay's emitted string to the U it actually produces — a silent
+    loft-scored roof if the string ever stops containing "sloping ceiling"."""
+    simulation = roof_overlay_for(roof_type_value, 0)
+    assert simulation is not None
+    overlay = simulation.building_parts[BuildingPartIdentifier.MAIN]
+    roof_type_lower = (overlay.roof_construction_type or "").lower()
+    is_sloping = "sloping ceiling" in roof_type_lower
+    return u_roof(
+        country=Country.ENG,
+        age_band=age_band,
+        insulation_thickness_mm=overlay.roof_insulation_thickness,
+        is_sloping_ceiling=is_sloping,
+        is_pitched_sloping_ceiling=is_sloping,
+    )
 
 _FLAT_THICKNESS_MEMBERS: list[tuple[RoofType, int]] = [
     (RoofType.FLAT_12MM, 12),
@@ -218,6 +240,32 @@ def test_sloping_ceiling_as_built_defers_to_the_age_band_default() -> None:
     assert overlay.roof_insulation_thickness is None
 
 
+def test_as_built_sloping_ceiling_scores_the_slope_default_not_the_loft_floor() -> None:
+    # ADR-0066: an as-built sloping ceiling at an old band takes Table 18 col (3)
+    # (band F = 0.68 W/m²K), NOT the loft col (1) 0.40 "modern-retrofit" floor it
+    # was mis-scored at when the classifier routed it onto the loft ladder. This
+    # is the whole point of the family — the age-band default must be the slope
+    # column, driven by the overlay's construction string.
+
+    # Act
+    u_value = _resolved_roof_u("Pitched, sloping ceiling, as built", age_band="F")
+
+    # Assert — col (3), not the loft col (1) 0.40.
+    assert abs(u_value - 0.68) <= 1e-4
+
+
+def test_known_depth_sloping_ceiling_scores_the_insulated_slope_ladder() -> None:
+    # ADR-0066: a known-depth sloping ceiling scores on Table 17 col (1a)
+    # "insulated slope" — 150 mm → 0.30 W/m²K (Elmhurst-confirmed, byte-identical
+    # to the loft col (1) value, so it is a *deliberate* match, not a fallback).
+
+    # Act
+    u_value = _resolved_roof_u("Pitched, sloping ceiling, 150 mm insulation", age_band="F")
+
+    # Assert
+    assert abs(u_value - 0.30) <= 1e-4
+
+
 @pytest.mark.parametrize(
     "roof_type_value",
     [