diff --git a/packages/domain/src/domain/ml/tests/_fixtures.py b/packages/domain/src/domain/ml/tests/_fixtures.py
index df64c43d..0d139839 100644
--- a/packages/domain/src/domain/ml/tests/_fixtures.py
+++ b/packages/domain/src/domain/ml/tests/_fixtures.py
@@ -222,6 +222,10 @@ def make_minimal_sap10_epc(
     pv_battery_count: int = 0,
     pv_battery_capacity_per_unit_kwh: Optional[float] = None,
     wind_turbines_count: int = 0,
+    mechanical_ventilation: Optional[int] = None,
+    mechanical_vent_duct_type: Optional[int] = None,
+    blocked_chimneys_count: Optional[int] = None,
+    pressure_test: Optional[int] = None,
 ) -> EpcPropertyData:
     """Construct a minimal valid SAP10 EpcPropertyData with parametrisable targets."""
     return EpcPropertyData(
@@ -304,6 +308,10 @@ def make_minimal_sap10_epc(
         built_form=built_form,
         region_code=region_code,
         country_code=country_code,
+        mechanical_ventilation=mechanical_ventilation,
+        mechanical_vent_duct_type=mechanical_vent_duct_type,
+        blocked_chimneys_count=blocked_chimneys_count,
+        pressure_test=pressure_test,
         renewable_heat_incentive=RenewableHeatIncentive(
             space_heating_kwh=space_heating_kwh,
             water_heating_kwh=water_heating_kwh,
diff --git a/packages/domain/src/domain/ml/tests/test_transform.py b/packages/domain/src/domain/ml/tests/test_transform.py
index 3853a051..66116fbe 100644
--- a/packages/domain/src/domain/ml/tests/test_transform.py
+++ b/packages/domain/src/domain/ml/tests/test_transform.py
@@ -1040,6 +1040,53 @@ def test_to_row_extracts_energy_source_booleans() -> None:
     assert row["is_dwelling_export_capable"] is True
 
 
+_VENTILATION_FEATURES_NULLABLE: dict[str, tuple[type, bool, bool]] = {
+    "mechanical_ventilation": (int, True, True),
+    "mechanical_vent_duct_type": (int, True, True),
+    "blocked_chimneys_count": (int, True, False),
+    "pressure_test": (int, True, False),
+}
+
+
+def test_schema_advertises_ventilation_features() -> None:
+    # Arrange
+    transform = EpcMlTransform()
+
+    # Act
+    schema = transform.schema()
+
+    # Assert
+    for name, (expected_dtype, expected_nullable, expected_categorical) in (
+        _VENTILATION_FEATURES_NULLABLE.items()
+    ):
+        assert name in schema.feature_columns, name
+        column = schema.feature_columns[name]
+        assert column.dtype is expected_dtype, name
+        assert column.nullable is expected_nullable, name
+        assert column.categorical is expected_categorical, name
+
+
+def test_to_row_extracts_ventilation_features() -> None:
+    # Arrange — MVHR (mechanical_ventilation code 4), duct type 3
+    epc = make_minimal_sap10_epc(
+        energy_rating_current=82,
+        mechanical_ventilation=4,
+        mechanical_vent_duct_type=3,
+        blocked_chimneys_count=1,
+        pressure_test=4,
+    )
+    transform = EpcMlTransform()
+
+    # Act
+    row = transform.to_row(epc)
+
+    # Assert
+    assert row["mechanical_ventilation"] == 4
+    assert row["mechanical_vent_duct_type"] == 3
+    assert row["blocked_chimneys_count"] == 1
+    assert row["pressure_test"] == 4
+
+
 def test_to_row_area_weights_window_u_value_and_solar_transmittance() -> None:
     # Arrange — two windows with transmission details; one without.
     sap_windows = [
diff --git a/packages/domain/src/domain/ml/transform.py b/packages/domain/src/domain/ml/transform.py
index eeef45d4..9e1fc662 100644
--- a/packages/domain/src/domain/ml/transform.py
+++ b/packages/domain/src/domain/ml/transform.py
@@ -417,6 +417,23 @@ _FEATURE_COLUMNS: dict[str, ColumnSpec] = {
         dtype=bool, nullable=False,
         description="Dwelling has an export-capable connection (eligible for SEG).",
     ),
+    # Ventilation — flat fields direct off EpcPropertyData
+    "mechanical_ventilation": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Mechanical ventilation SAP10 code (0=natural, 1-6 per epc_codes.csv enum).",
+    ),
+    "mechanical_vent_duct_type": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Mechanical ventilation duct type SAP10 code.",
+    ),
+    "blocked_chimneys_count": ColumnSpec(
+        dtype=int, nullable=True,
+        description="Number of blocked / capped-off chimneys.",
+    ),
+    "pressure_test": ColumnSpec(
+        dtype=int, nullable=True,
+        description="Air-tightness pressure-test SAP10 code.",
+    ),
 }
 
 
@@ -536,6 +553,11 @@ class EpcMlTransform:
             **pv_aggregates,
             # Features — battery, wind turbine, mains gas + smart meter flags
             **energy_source_other,
+            # Features — ventilation
+            "mechanical_ventilation": epc.mechanical_ventilation,
+            "mechanical_vent_duct_type": epc.mechanical_vent_duct_type,
+            "blocked_chimneys_count": epc.blocked_chimneys_count,
+            "pressure_test": epc.pressure_test,
             # Targets
             "sap_score": epc.energy_rating_current,
             "co2_emissions": epc.co2_emissions_current,