Fold landlord overrides onto the lodged EPC to form the Effective EPC 🟩

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

domain/property/property.py

@@ -1,10 +1,12 @@
 from __future__ import annotations
 
-from dataclasses import dataclass
-from typing import Literal, Optional
+from dataclasses import dataclass, field
+from typing import Literal, Optional, Sequence
 
 from datatypes.epc.domain.epc_property_data import EpcPropertyData
 from domain.geospatial.planning_restrictions import PlanningRestrictions
+from domain.modelling.scoring.overlay_applicator import apply_simulations
+from domain.modelling.simulation import EpcSimulation
 from domain.property.site_notes import SiteNotes
 
 SourcePath = Literal["site_notes", "epc_with_overlay", "predicted"]
@@ -43,6 +45,11 @@ class Property:
     # structural). Used as the Effective EPC only as a last resort — when there is
     # neither a lodged EPC nor Site Notes; a real source always wins.
     predicted_epc: Optional[EpcPropertyData] = None
+    # Resolved Landlord Overrides as Simulation Overlays, folded onto the lodged
+    # EPC to form the Effective EPC (ADR-0032). Empty when the Property has no
+    # overrides — the EPC is then returned unchanged. Only applied on the
+    # `epc_with_overlay` path; never when Site Notes are the source.
+    landlord_overrides: Sequence[EpcSimulation] = field(default_factory=tuple)
     # The current open-market value (a Property Valuation) — externally sourced
     # and mostly absent; feeds the Plan's Valuation Uplift £ forms (ADR-0018).
     current_market_value: Optional[float] = None
@@ -78,10 +85,11 @@ class Property:
     def effective_epc(self) -> EpcPropertyData:
         """The EpcPropertyData the modelling pipeline scores against.
 
-        Path 1: the Site Notes' surveyed data. Path 2: the public EPC (Landlord
-        Overrides overlay is a later slice — returned as-is for now). Path 3: a
-        neighbour-synthesised EPC (EPC Prediction gap-fill, ADR-0031), used only
-        when neither real source is present.
+        Path 1: the Site Notes' surveyed data. Path 2: the public EPC with any
+        Landlord Overrides folded on as Simulation Overlays (ADR-0032) — returned
+        as-is when there are none. Path 3: a neighbour-synthesised EPC (EPC
+        Prediction gap-fill, ADR-0031), used only when neither real source is
+        present.
         """
         if self.source_path == "site_notes":
             assert self.site_notes is not None
@@ -90,4 +98,6 @@ class Property:
             assert self.predicted_epc is not None
             return self.predicted_epc
         assert self.epc is not None
+        if self.landlord_overrides:
+            return apply_simulations(self.epc, self.landlord_overrides)
         return self.epc

tests/domain/property/test_property_landlord_overlay.py

@@ -0,0 +1,82 @@
+"""Effective EPC on the `epc_with_overlay` path folds Landlord Overrides (ADR-0032).
+
+When a Property has a lodged EPC and resolved Landlord Overrides (as Simulation
+Overlays), the Effective EPC is the lodged EPC with those overlays applied — so
+the calculator scores what the landlord knows beyond the cert. With no overrides
+the lodged EPC is returned unchanged.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+from typing import Any
+
+from datatypes.epc.domain.epc_property_data import (
+    BuildingPartIdentifier,
+    EpcPropertyData,
+)
+from domain.epc.wall_type_overlay import wall_overlay_for
+from domain.property.property import Property, PropertyIdentity
+
+_JSON_SAMPLES = Path(__file__).resolve().parents[3] / "backend/epc_api/json_samples"
+
+
+def _epc() -> EpcPropertyData:
+    raw: dict[str, Any] = json.loads(
+        (_JSON_SAMPLES / "RdSAP-Schema-21.0.0" / "epc.json").read_text()
+    )
+    from datatypes.epc.domain.mapper import EpcPropertyDataMapper
+
+    return EpcPropertyDataMapper.from_api_response(raw)
+
+
+def _identity() -> PropertyIdentity:
+    return PropertyIdentity(
+        portfolio_id=1, postcode="A0 0AA", address="1 Some Street", uprn=12345
+    )
+
+
+def _main_wall(epc: EpcPropertyData) -> Any:
+    return next(
+        part
+        for part in epc.sap_building_parts
+        if part.identifier is BuildingPartIdentifier.MAIN
+    )
+
+
+def test_effective_epc_folds_the_wall_override_onto_the_main_part() -> None:
+    # Arrange — a Property with a lodged EPC and a solid-brick/internal-insulation
+    # wall override.
+    overlay = wall_overlay_for("Solid brick, with internal insulation", 0)
+    assert overlay is not None
+    prop = Property(identity=_identity(), epc=_epc(), landlord_overrides=[overlay])
+
+    # Act
+    main = _main_wall(prop.effective_epc)
+
+    # Assert — the override's codes are present on the main wall.
+    assert main.wall_construction == 3
+    assert main.wall_insulation_type == 3
+
+
+def test_effective_epc_is_the_lodged_epc_when_there_are_no_overrides() -> None:
+    # Arrange — a Property with an EPC and no Landlord Overrides.
+    prop = Property(identity=_identity(), epc=_epc())
+
+    # Act
+    effective = prop.effective_epc
+
+    # Assert — the lodged EPC is returned untouched (same object, no fold).
+    assert effective is prop.epc
+
+
+def test_baseline_wall_is_unchanged_when_no_override_applies() -> None:
+    # Arrange — the lodged main wall is cavity (construction 4).
+    prop = Property(identity=_identity(), epc=_epc())
+
+    # Act
+    main = _main_wall(prop.effective_epc)
+
+    # Assert
+    assert main.wall_construction == 4