diff --git a/domain/epc_prediction/prediction_comparison.py b/domain/epc_prediction/prediction_comparison.py
index 995ae5ca..8af5000b 100644
--- a/domain/epc_prediction/prediction_comparison.py
+++ b/domain/epc_prediction/prediction_comparison.py
@@ -12,6 +12,7 @@ runner, which has the calculator and the lodged SAP.
 from __future__ import annotations
 
 from dataclasses import dataclass
+from typing import Optional
 
 from datatypes.epc.domain.epc_property_data import EpcPropertyData, SapBuildingPart
 
@@ -19,9 +20,16 @@ from datatypes.epc.domain.epc_property_data import EpcPropertyData, SapBuildingP
 @dataclass(frozen=True)
 class PredictionComparison:
     """One Property's prediction accuracy: classification hits + geometry
-    residuals (predicted − actual)."""
+    residuals (predicted − actual). A categorical hit is `None` ("not
+    applicable") when the actual lodges no value there, so the harness can keep
+    it out of the classification-rate denominator rather than score a free win.
+    """
 
     wall_construction_correct: bool
+    wall_insulation_type_correct: bool
+    construction_age_band_correct: bool
+    roof_construction_correct: Optional[bool]
+    floor_construction_correct: Optional[bool]
     floor_area_residual: float
     building_parts_residual: int
     window_count_residual: int
@@ -32,6 +40,21 @@ def _main(epc: EpcPropertyData) -> SapBuildingPart:
     return epc.sap_building_parts[0]
 
 
+def _main_floor_construction(epc: EpcPropertyData) -> Optional[int]:
+    """The main building part's ground-floor construction code, or None when no
+    floor dimension is lodged."""
+    dims = _main(epc).sap_floor_dimensions
+    return dims[0].floor_construction if dims else None
+
+
+def _classify(predicted: object, actual: object) -> Optional[bool]:
+    """A categorical hit: None ("not applicable") when the actual is absent,
+    else whether the predicted value matches it."""
+    if actual is None:
+        return None
+    return predicted == actual
+
+
 def _total_window_area(epc: EpcPropertyData) -> float:
     return sum(w.window_width * w.window_height for w in epc.sap_windows)
 
@@ -45,6 +68,20 @@ def compare_prediction(
         wall_construction_correct=(
             _main(predicted).wall_construction == _main(actual).wall_construction
         ),
+        wall_insulation_type_correct=(
+            _main(predicted).wall_insulation_type
+            == _main(actual).wall_insulation_type
+        ),
+        construction_age_band_correct=(
+            _main(predicted).construction_age_band
+            == _main(actual).construction_age_band
+        ),
+        roof_construction_correct=_classify(
+            _main(predicted).roof_construction, _main(actual).roof_construction
+        ),
+        floor_construction_correct=_classify(
+            _main_floor_construction(predicted), _main_floor_construction(actual)
+        ),
         floor_area_residual=(
             predicted.total_floor_area_m2 - actual.total_floor_area_m2
         ),
diff --git a/scripts/validate_epc_prediction.py b/scripts/validate_epc_prediction.py
index fee28d9e..25890445 100644
--- a/scripts/validate_epc_prediction.py
+++ b/scripts/validate_epc_prediction.py
@@ -75,7 +75,15 @@ def main() -> None:
     calculator = Sap10Calculator()
     predictor = EpcPrediction()
 
-    wall_hits = wall_total = 0
+    # Classification: name -> [hits, applicable-total]. A None hit (the actual
+    # lodges no value) is excluded from the denominator.
+    categoricals: dict[str, list[int]] = {
+        "wall_construction": [0, 0],
+        "wall_insulation_type": [0, 0],
+        "construction_age_band": [0, 0],
+        "roof_construction": [0, 0],
+        "floor_construction": [0, 0],
+    }
     floor_res: list[float] = []
     window_count_res: list[int] = []
     window_area_res: list[float] = []
@@ -105,8 +113,19 @@ def main() -> None:
             predicted_n += 1
 
             cmp = compare_prediction(predicted, actual)
-            wall_total += 1
-            wall_hits += int(cmp.wall_construction_correct)
+            _tally(categoricals["wall_construction"], cmp.wall_construction_correct)
+            _tally(
+                categoricals["wall_insulation_type"],
+                cmp.wall_insulation_type_correct,
+            )
+            _tally(
+                categoricals["construction_age_band"],
+                cmp.construction_age_band_correct,
+            )
+            _tally(categoricals["roof_construction"], cmp.roof_construction_correct)
+            _tally(
+                categoricals["floor_construction"], cmp.floor_construction_correct
+            )
             floor_res.append(cmp.floor_area_residual)
             window_count_res.append(cmp.window_count_residual)
             window_area_res.append(cmp.total_window_area_residual)
@@ -130,9 +149,10 @@ def main() -> None:
 
     print(f"corpus: {CORPUS}")
     print(f"predicted {predicted_n} held-out certs ({skipped_no_cohort} had no cohort)\n")
-    if wall_total:
-        print(f"CLASSIFICATION  wall_construction: {wall_hits}/{wall_total} = "
-              f"{wall_hits / wall_total:.1%}")
+    for name, (hits, total) in categoricals.items():
+        if total:
+            print(f"CLASSIFICATION  {name}: {hits}/{total} = {hits / total:.1%}")
+    print()
     _residual("floor_area (m2)", floor_res)
     _residual("window_count", [float(x) for x in window_count_res])
     _residual("total_window_area (m2)", window_area_res)
@@ -143,6 +163,15 @@ def main() -> None:
     _sap_line("SAP |neighbour-mean − lodged| (baseline)", sap_vs_neighbour_mean)
 
 
+def _tally(counter: list[int], hit: Optional[bool]) -> None:
+    """Record one classification outcome: a None hit (actual absent) is not
+    applicable and skipped; else increment the applicable total and the hits."""
+    if hit is None:
+        return
+    counter[1] += 1
+    counter[0] += int(hit)
+
+
 def _residual(label: str, values: list[float]) -> None:
     if not values:
         print(f"RESIDUAL  {label}: (none)")
diff --git a/tests/domain/epc_prediction/test_prediction_comparison.py b/tests/domain/epc_prediction/test_prediction_comparison.py
index 0ce19384..583e7e0d 100644
--- a/tests/domain/epc_prediction/test_prediction_comparison.py
+++ b/tests/domain/epc_prediction/test_prediction_comparison.py
@@ -5,11 +5,12 @@ and residuals on the geometry. Pure; SAP residual is computed in the runner
 (it needs the calculator + lodged SAP).
 """
 
-from typing import Optional
+from typing import Optional, Union
 
 from datatypes.epc.domain.epc_property_data import (
     EpcPropertyData,
     SapBuildingPart,
+    SapFloorDimension,
     SapWindow,
 )
 from domain.epc_prediction.prediction_comparison import compare_prediction
@@ -18,6 +19,10 @@ from domain.epc_prediction.prediction_comparison import compare_prediction
 def _epc(
     *,
     wall_construction: int = 1,
+    wall_insulation_type: Union[int, str] = 1,
+    construction_age_band: str = "K",
+    roof_construction: Optional[int] = 1,
+    floor_construction: Optional[int] = 1,
     floor_area: float = 80.0,
     building_parts: int = 1,
     windows: Optional[list[tuple[float, float]]] = None,
@@ -28,6 +33,12 @@ def _epc(
     for _ in range(building_parts):
         part: SapBuildingPart = object.__new__(SapBuildingPart)
         part.wall_construction = wall_construction
+        part.wall_insulation_type = wall_insulation_type
+        part.construction_age_band = construction_age_band
+        part.roof_construction = roof_construction
+        floor_dim: SapFloorDimension = object.__new__(SapFloorDimension)
+        floor_dim.floor_construction = floor_construction
+        part.sap_floor_dimensions = [floor_dim]
         parts.append(part)
     epc.sap_building_parts = parts
     sap_windows: list[SapWindow] = []
@@ -64,6 +75,46 @@ def test_flags_an_incorrect_main_wall_construction_classification() -> None:
     assert comparison.wall_construction_correct is False
 
 
+def test_classifies_the_extra_homogeneous_categoricals() -> None:
+    # Arrange — predicted agrees on age band, wall insulation, roof and floor
+    # construction with the actual; only wall insulation differs.
+    predicted = _epc(
+        construction_age_band="K",
+        wall_insulation_type=2,
+        roof_construction=3,
+        floor_construction=1,
+    )
+    actual = _epc(
+        construction_age_band="K",
+        wall_insulation_type=1,
+        roof_construction=3,
+        floor_construction=1,
+    )
+
+    # Act
+    comparison = compare_prediction(predicted, actual)
+
+    # Assert
+    assert comparison.construction_age_band_correct is True
+    assert comparison.wall_insulation_type_correct is False
+    assert comparison.roof_construction_correct is True
+    assert comparison.floor_construction_correct is True
+
+
+def test_categorical_hit_is_not_applicable_when_actual_is_absent() -> None:
+    # Arrange — the actual lodges no roof construction (a flat under another
+    # dwelling). A hit there is not applicable, not a free win, so it must not
+    # count towards the roof classification rate.
+    predicted = _epc(roof_construction=3)
+    actual = _epc(roof_construction=None)
+
+    # Act
+    comparison = compare_prediction(predicted, actual)
+
+    # Assert
+    assert comparison.roof_construction_correct is None
+
+
 def test_reports_the_floor_area_residual_as_predicted_minus_actual() -> None:
     # Arrange — predicted 90 m², actual 100 m² (a 10 m² under-prediction).
     predicted = _epc(floor_area=90.0)