Historic stable attributes condition cohort selection on the relax ladder 🟥

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

domain/epc_prediction/prediction_target.py

@@ -34,6 +34,12 @@ class PredictionTarget:
     # The target Property's own coordinates (resolved from its UPRN), against
     # which neighbours are distance-weighted. None disables geo-weighting.
     coordinates: Optional[Coordinates] = None
+    # Stable attributes observed on an expired Historic EPC condition selection
+    # the same way (ADR-0054): RdSAP Table S1 band letter, modern main_fuel
+    # code, and a ±5% floor-area band. None leaves each filter inactive.
+    construction_age_band: Optional[str] = None
+    main_fuel: Optional[int] = None
+    total_floor_area_m2: Optional[float] = None
 
 
 @dataclass(frozen=True)

tests/domain/epc_prediction/test_comparable_properties.py

@@ -8,7 +8,12 @@ enough remain, weighted by recency × similarity. Pure domain logic.
 from datetime import date
 from typing import Optional, Union
 
-from datatypes.epc.domain.epc_property_data import EpcPropertyData, SapBuildingPart
+from datatypes.epc.domain.epc_property_data import (
+    EpcPropertyData,
+    MainHeatingDetail,
+    SapBuildingPart,
+    SapHeating,
+)
 from domain.epc_prediction.comparable_properties import (
     ComparableProperty,
     ComparableProperties,
@@ -25,6 +30,9 @@ def _comparable(
     wall_construction: Optional[Union[int, str]] = None,
     address: Optional[str] = None,
     registration_date: Optional[date] = None,
+    construction_age_band: Optional[str] = None,
+    main_fuel: Optional[int] = None,
+    total_floor_area_m2: Optional[float] = None,
 ) -> ComparableProperty:
     """A ComparableProperty carrying only the fields under test (opaque EpcPropertyData
     with property_type / built_form / main wall set — the partial-instance idiom)."""
@@ -34,7 +42,17 @@ def _comparable(
     main: SapBuildingPart = object.__new__(SapBuildingPart)
     if wall_construction is not None:
         main.wall_construction = wall_construction
+    if construction_age_band is not None:
+        main.construction_age_band = construction_age_band
     epc.sap_building_parts = [main]
+    if main_fuel is not None:
+        detail: MainHeatingDetail = object.__new__(MainHeatingDetail)
+        detail.main_fuel_type = main_fuel
+        heating: SapHeating = object.__new__(SapHeating)
+        heating.main_heating_details = [detail]
+        epc.sap_heating = heating
+    if total_floor_area_m2 is not None:
+        epc.total_floor_area_m2 = total_floor_area_m2
     return ComparableProperty(
         epc=epc,
         certificate_number=certificate_number,
@@ -171,3 +189,106 @@ def test_known_wall_override_relaxes_when_too_few_match() -> None:
 
     # Assert — relaxed: all eight houses retained.
     assert len(result.members) == 8
+
+
+def test_historic_age_band_conditions_the_cohort() -> None:
+    # Arrange — the expired cert observed band C (1930-1949); 5 band-C houses +
+    # 2 band-G houses in the cohort (ADR-0054).
+    target = PredictionTarget(
+        postcode="LS6 1AA", property_type="2", construction_age_band="C"
+    )
+    candidates = [
+        _comparable(
+            property_type="2", construction_age_band="C", certificate_number=f"C{i}"
+        )
+        for i in range(5)
+    ] + [
+        _comparable(
+            property_type="2", construction_age_band="G", certificate_number=f"G{i}"
+        )
+        for i in range(2)
+    ]
+
+    # Act
+    result: ComparableProperties = select_comparables(
+        target, candidates, minimum_cohort=5
+    )
+
+    # Assert — only the same-age-band comparables remain.
+    assert {c.certificate_number for c in result.members} == {
+        "C0", "C1", "C2", "C3", "C4"
+    }
+
+
+def test_historic_main_fuel_conditions_the_cohort() -> None:
+    # Arrange — the expired cert observed mains gas (26); 5 gas + 2 electric
+    # (29) houses in the cohort (ADR-0054).
+    target = PredictionTarget(postcode="LS6 1AA", property_type="2", main_fuel=26)
+    candidates = [
+        _comparable(property_type="2", main_fuel=26, certificate_number=f"G{i}")
+        for i in range(5)
+    ] + [
+        _comparable(property_type="2", main_fuel=29, certificate_number=f"E{i}")
+        for i in range(2)
+    ]
+
+    # Act
+    result: ComparableProperties = select_comparables(
+        target, candidates, minimum_cohort=5
+    )
+
+    # Assert
+    assert {c.certificate_number for c in result.members} == {
+        "G0", "G1", "G2", "G3", "G4"
+    }
+
+
+def test_floor_area_band_keeps_comparables_within_5_percent() -> None:
+    # Arrange — the expired cert observed 100 m²; the band is ±5% (ADR-0054):
+    # 96 and 104.9 are in, 90 and 111 are out.
+    target = PredictionTarget(
+        postcode="LS6 1AA", property_type="2", total_floor_area_m2=100.0
+    )
+    candidates = [
+        _comparable(property_type="2", total_floor_area_m2=96.0, certificate_number="A"),
+        _comparable(
+            property_type="2", total_floor_area_m2=104.9, certificate_number="B"
+        ),
+        _comparable(property_type="2", total_floor_area_m2=90.0, certificate_number="X"),
+        _comparable(
+            property_type="2", total_floor_area_m2=111.0, certificate_number="Y"
+        ),
+    ]
+
+    # Act
+    result: ComparableProperties = select_comparables(
+        target, candidates, minimum_cohort=2
+    )
+
+    # Assert
+    assert {c.certificate_number for c in result.members} == {"A", "B"}
+
+
+def test_floor_area_band_relaxes_when_too_few_match() -> None:
+    # Arrange — only one comparable inside the ±5% band (< k=2): the band must
+    # relax rather than starve the cohort (graceful degradation, ADR-0029).
+    target = PredictionTarget(
+        postcode="LS6 1AA", property_type="2", total_floor_area_m2=100.0
+    )
+    candidates = [
+        _comparable(property_type="2", total_floor_area_m2=99.0, certificate_number="A"),
+        _comparable(
+            property_type="2", total_floor_area_m2=140.0, certificate_number="X"
+        ),
+        _comparable(
+            property_type="2", total_floor_area_m2=150.0, certificate_number="Y"
+        ),
+    ]
+
+    # Act
+    result: ComparableProperties = select_comparables(
+        target, candidates, minimum_cohort=2
+    )
+
+    # Assert — relaxed: all three retained.
+    assert len(result.members) == 3