diff --git a/datatypes/epc/domain/epc_property_data.py b/datatypes/epc/domain/epc_property_data.py
index c7cc4f0f..a84d20db 100644
--- a/datatypes/epc/domain/epc_property_data.py
+++ b/datatypes/epc/domain/epc_property_data.py
@@ -360,6 +360,10 @@ class EpcPropertyData:
     main_heating_controls: Optional[EnergyElement] = (
         None  # site notes has heating_and_hot_water.main_heating.controls: str - doesn't map to EnergyElement
     )
+    # Air-tightness EnergyElement (description + ratings) — kept as input even though
+    # ratings are derived, because the `.description` text categorizes the building's
+    # permeability class when no pressure test was carried out.
+    air_tightness: Optional[EnergyElement] = None
     current_energy_efficiency_band: Optional[Epc] = None  # not available in site notes?
     environmental_impact_current: Optional[int] = None
     heating_cost_current: Optional[float] = None
diff --git a/datatypes/epc/domain/mapper.py b/datatypes/epc/domain/mapper.py
index a2bc1a02..a3e85b0e 100644
--- a/datatypes/epc/domain/mapper.py
+++ b/datatypes/epc/domain/mapper.py
@@ -16,6 +16,7 @@ from datatypes.epc.domain.epc_property_data import (
     SapAlternativeWall,
     SapBuildingPart,
     SapEnergySource,
+    SapFlatDetails,
     SapFloorDimension,
     SapHeating,
     SapRoomInRoof,
@@ -1313,6 +1314,11 @@ class EpcPropertyDataMapper:
             has_fixed_air_conditioning=schema.has_fixed_air_conditioning == "true",
             conservatory_type=schema.conservatory_type,
             has_conservatory=schema.conservatory_type != 1,
+            has_heated_separate_conservatory=(
+                schema.has_heated_separate_conservatory == "true"
+                if schema.has_heated_separate_conservatory is not None
+                else None
+            ),
             # Counts
             door_count=schema.door_count,
             habitable_rooms_count=schema.habitable_room_count,
@@ -1529,6 +1535,35 @@ class EpcPropertyDataMapper:
             # Dwelling-level inputs used as ML features.
             multiple_glazed_proportion=schema.multiple_glazed_proportion,
             extract_fans_count=schema.extract_fans_count,
+            # Air-tightness EnergyElement (description carries permeability class).
+            air_tightness=(
+                EpcPropertyDataMapper._map_energy_element(schema.air_tightness)
+                if schema.air_tightness is not None
+                else None
+            ),
+            # Main-heating-controls EnergyElement (first control system if multiple).
+            main_heating_controls=(
+                EpcPropertyDataMapper._map_energy_element(schema.main_heating_controls[0])
+                if schema.main_heating_controls
+                else None
+            ),
+            # Flat-only nested block: present in ~33% of certs.
+            sap_flat_details=(
+                SapFlatDetails(
+                    level=schema.sap_flat_details.level,
+                    top_storey=schema.sap_flat_details.top_storey,
+                    flat_location=schema.sap_flat_details.flat_location,
+                    heat_loss_corridor=schema.sap_flat_details.heat_loss_corridor,
+                    storey_count=schema.sap_flat_details.storey_count,
+                    unheated_corridor_length_m=(
+                        int(_measurement_value(schema.sap_flat_details.unheated_corridor_length))
+                        if schema.sap_flat_details.unheated_corridor_length is not None
+                        else None
+                    ),
+                )
+                if schema.sap_flat_details is not None
+                else None
+            ),
         )
 
     @staticmethod
diff --git a/datatypes/epc/schema/rdsap_schema_21_0_1.py b/datatypes/epc/schema/rdsap_schema_21_0_1.py
index f4531c52..8563180c 100644
--- a/datatypes/epc/schema/rdsap_schema_21_0_1.py
+++ b/datatypes/epc/schema/rdsap_schema_21_0_1.py
@@ -343,6 +343,7 @@ class RdSapSchema21_0_1:
     incandescent_fixed_lighting_bulbs_count: int
     # Fields below are present in some certs but absent in many real-world responses;
     # see datatypes/epc/schema/tests/fixtures/21_0_1_real.json for a representative cert.
+    air_tightness: Optional[EnergyElement] = None
     extract_fans_count: Optional[int] = None
     wet_rooms_count: Optional[int] = None
     open_chimneys_count: Optional[int] = None
diff --git a/packages/domain/src/domain/ml/transform.py b/packages/domain/src/domain/ml/transform.py
index 9f9fd79f..aa9aaa40 100644
--- a/packages/domain/src/domain/ml/transform.py
+++ b/packages/domain/src/domain/ml/transform.py
@@ -498,6 +498,83 @@ _FEATURE_COLUMNS: dict[str, ColumnSpec] = {
         dtype=int, nullable=True,
         description="Number of extract fans (ventilation/heat-loss proxy).",
     ),
+    # Heating — heating-system identity + flow temp + multi-system fraction.
+    "primary_sap_main_heating_code": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="SAP10 main heating type code (canonical heating-system enum).",
+    ),
+    "primary_emitter_temperature": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Primary heating emitter temperature class (0=standard, 1=low-temp).",
+    ),
+    "primary_main_heating_fraction": ColumnSpec(
+        dtype=float, nullable=True,
+        description="Fraction of space heating delivered by the primary main heating system.",
+    ),
+    # Hot water — immersion type + presence of shower outlet block.
+    "immersion_heating_type": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Electric immersion heater type SAP10 code.",
+    ),
+    "shower_outlet_count": ColumnSpec(
+        dtype=int, nullable=False,
+        description="1 if any shower_outlet block is declared on sap_heating, else 0.",
+    ),
+    # Windows — per-window-type share aggregates.
+    "window_pct_living": ColumnSpec(
+        dtype=float, nullable=True,
+        description="Area share of windows with window_type == 1 (living room).",
+    ),
+    "window_pct_external": ColumnSpec(
+        dtype=float, nullable=True,
+        description="Area share of windows with window_location == 0 (external).",
+    ),
+    "window_pct_permanent_shutters": ColumnSpec(
+        dtype=float, nullable=True,
+        description="Area share of windows with permanent_shutters_present truthy.",
+    ),
+    # Dwelling — conservatory + flat-only block.
+    "conservatory_type": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Conservatory SAP10 code (1=none, 2=heated, 3=unheated, ...).",
+    ),
+    "has_heated_separate_conservatory": ColumnSpec(
+        dtype=bool, nullable=True,
+        description="Whether the dwelling has a heated separate conservatory.",
+    ),
+    "flat_level": ColumnSpec(
+        dtype=int, nullable=True,
+        description="Flat-only: floor number on which the flat sits.",
+    ),
+    "flat_top_storey": ColumnSpec(
+        dtype=str, nullable=True, categorical=True,
+        description="Flat-only: Y/N flag indicating whether this is the top storey.",
+    ),
+    "flat_storey_count": ColumnSpec(
+        dtype=int, nullable=True,
+        description="Flat-only: storey count of the building containing the flat.",
+    ),
+    "flat_location": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Flat-only: location SAP10 code (corner/middle/...).",
+    ),
+    "flat_heat_loss_corridor": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Flat-only: heat-loss-corridor SAP10 code.",
+    ),
+    # Energy supply categoricals.
+    "meter_type": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Electricity meter type SAP10 code (1=Standard, 2=Off-peak, ...).",
+    ),
+    "pv_connection": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="PV connection topology SAP10 code.",
+    ),
+    "wind_turbines_terrain_type": ColumnSpec(
+        dtype=int, nullable=True, categorical=True,
+        description="Wind-turbine terrain type SAP10 code.",
+    ),
 }
 
 
@@ -649,6 +726,28 @@ class EpcMlTransform:
             "number_baths": epc.sap_heating.number_baths,
             "number_baths_wwhrs": epc.sap_heating.number_baths_wwhrs,
             "extract_fans_count": epc.extract_fans_count,
+            # Features — conservatory + flat-only block
+            "conservatory_type": epc.conservatory_type,
+            "has_heated_separate_conservatory": epc.has_heated_separate_conservatory,
+            "flat_level": (
+                _int_or_none(epc.sap_flat_details.level) if epc.sap_flat_details else None
+            ),
+            "flat_top_storey": (
+                epc.sap_flat_details.top_storey if epc.sap_flat_details else None
+            ),
+            "flat_storey_count": (
+                _int_or_none(epc.sap_flat_details.storey_count) if epc.sap_flat_details else None
+            ),
+            "flat_location": (
+                _int_or_none(epc.sap_flat_details.flat_location) if epc.sap_flat_details else None
+            ),
+            "flat_heat_loss_corridor": (
+                _int_or_none(epc.sap_flat_details.heat_loss_corridor) if epc.sap_flat_details else None
+            ),
+            # Features — energy supply categoricals
+            "meter_type": _meter_type_int(epc.sap_energy_source.meter_type),
+            "pv_connection": epc.sap_energy_source.pv_connection,
+            "wind_turbines_terrain_type": _wind_terrain_int(epc.sap_energy_source.wind_turbines_terrain_type),
             # Targets
             "sap_score": epc.energy_rating_current,
             "co2_emissions": epc.co2_emissions_current,
@@ -762,6 +861,8 @@ def _heating_aggregates(sap_heating: SapHeating) -> dict[str, Any]:
     domain object — Union-int values pass through as int categoricals; str
     values (from site notes) coerce to None.
     """
+    shower_outlets = sap_heating.shower_outlets
+    shower_outlet_count = 1 if shower_outlets is not None else 0
     aggregates: dict[str, Any] = {
         "main_heating_count": len(sap_heating.main_heating_details),
         "primary_main_fuel_type": None,
@@ -772,6 +873,9 @@ def _heating_aggregates(sap_heating: SapHeating) -> dict[str, Any]:
         "primary_fan_flue_present": None,
         "primary_boiler_flue_type": None,
         "primary_central_heating_pump_age": None,
+        "primary_sap_main_heating_code": None,
+        "primary_emitter_temperature": None,
+        "primary_main_heating_fraction": None,
         "water_heating_code": sap_heating.water_heating_code,
         "water_heating_fuel": sap_heating.water_heating_fuel,
         "cylinder_size": (
@@ -782,6 +886,8 @@ def _heating_aggregates(sap_heating: SapHeating) -> dict[str, Any]:
         "cylinder_insulation_thickness_mm": sap_heating.cylinder_insulation_thickness_mm,
         "has_secondary_heating": sap_heating.secondary_fuel_type is not None,
         "secondary_fuel_type": sap_heating.secondary_fuel_type,
+        "immersion_heating_type": _int_or_none(sap_heating.immersion_heating_type),
+        "shower_outlet_count": shower_outlet_count,
     }
 
     if sap_heating.main_heating_details:
@@ -806,6 +912,9 @@ def _heating_aggregates(sap_heating: SapHeating) -> dict[str, Any]:
         aggregates["primary_central_heating_pump_age"] = (
             primary.central_heating_pump_age
         )
+        aggregates["primary_sap_main_heating_code"] = primary.sap_main_heating_code
+        aggregates["primary_emitter_temperature"] = _int_or_none(primary.emitter_temperature)
+        aggregates["primary_main_heating_fraction"] = primary.main_heating_fraction
 
     return aggregates
 
@@ -854,6 +963,25 @@ def _int_or_none(value: Any) -> Optional[int]:
     return value if isinstance(value, int) else None
 
 
+def _meter_type_int(value: Any) -> Optional[int]:
+    """Domain mapper coerces sap_energy_source.meter_type to str(int) for site-notes
+    compatibility ("1", "2", ...). Parse back to int for the categorical feature."""
+    if isinstance(value, int):
+        return value
+    if isinstance(value, str) and value.isdigit():
+        return int(value)
+    return None
+
+
+def _wind_terrain_int(value: Any) -> Optional[int]:
+    """Same shape as meter_type — int coerced to str by the 21.0.x mapper."""
+    if isinstance(value, int):
+        return value
+    if isinstance(value, str) and value.isdigit():
+        return int(value)
+    return None
+
+
 def _ground_floor(part: SapBuildingPart) -> Optional[Any]:
     """Pick the ground-floor `SapFloorDimension` (floor==0) for a building part.
 
@@ -987,6 +1115,9 @@ def _window_aggregates(windows: list[SapWindow]) -> dict[str, Any]:
         "window_avg_solar_transmittance": None,
         **glazed_type_areas,
         "window_pct_pvc_frame": None,
+        "window_pct_living": None,
+        "window_pct_external": None,
+        "window_pct_permanent_shutters": None,
     }
     if not windows:
         return aggregates
@@ -994,6 +1125,9 @@ def _window_aggregates(windows: list[SapWindow]) -> dict[str, Any]:
     total_area = 0.0
     draught_proofed_area = 0.0
     pvc_frame_area = 0.0
+    living_area = 0.0
+    external_area = 0.0
+    shutters_area = 0.0
     transmission_area = 0.0
     weighted_u_value = 0.0
     weighted_solar_transmittance = 0.0
@@ -1004,6 +1138,12 @@ def _window_aggregates(windows: list[SapWindow]) -> dict[str, Any]:
             draught_proofed_area += area
         if w.frame_material == "PVC":
             pvc_frame_area += area
+        if w.window_type == 1:  # living room
+            living_area += area
+        if w.window_location == 0:  # external (not conservatory)
+            external_area += area
+        if w.permanent_shutters_present is True or w.permanent_shutters_present == "Y":
+            shutters_area += area
         if isinstance(w.orientation, int) and w.orientation in _OCTANT_NAMES:
             octant_areas[_OCTANT_NAMES[w.orientation]] += area
         if isinstance(w.glazing_type, int) and w.glazing_type in _GLAZED_TYPE_CODES:
@@ -1025,6 +1165,9 @@ def _window_aggregates(windows: list[SapWindow]) -> dict[str, Any]:
             draught_proofed_area / total_area * 100.0
         )
         aggregates["window_pct_pvc_frame"] = pvc_frame_area / total_area
+        aggregates["window_pct_living"] = living_area / total_area
+        aggregates["window_pct_external"] = external_area / total_area
+        aggregates["window_pct_permanent_shutters"] = shutters_area / total_area
         for column, area in glazed_type_areas.items():
             aggregates[column] = area / total_area
     if transmission_area > 0: