diff --git a/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000477.py b/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000477.py
index 5505ab01..4fb5012d 100644
--- a/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000477.py
+++ b/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000477.py
@@ -26,6 +26,8 @@ from datatypes.epc.domain.epc_property_data import (
     SapRoomInRoofSurface,
     SapVentilation,
     SapWindow,
+    ShowerOutlet,
+    ShowerOutlets,
 )
 from domain.ml.tests._fixtures import (
     make_main_heating_detail,
@@ -47,13 +49,25 @@ _WC_CAVITY = 4
 
 
 def build_epc() -> EpcPropertyData:
-    """EpcPropertyData mirroring the Elmhurst 000477 inputs."""
+    """EpcPropertyData mirroring the Elmhurst 000477 inputs.
+
+    Field-level parity with `from_elmhurst_site_notes(Summary_000477.
+    pdf)` for the load-bearing field allow-list — every cohort hand-
+    built doubles as the ground-truth diff target for the Elmhurst
+    mapper. Cascade-equivalent encoding-only fields (descriptive floor/
+    roof strings, ventilation zero counts) are populated explicitly to
+    eliminate noise from `test_from_elmhurst_site_notes_matches_hand_
+    built_000477` diffs without altering the SAP cascade output (the
+    Section-10a 1e-4 pins in `test_e2e_elmhurst_sap_score.py` remain
+    GREEN against the worksheet PDF).
+    """
     main = SapBuildingPart(
         identifier=BuildingPartIdentifier.MAIN,
         construction_age_band="B",
         wall_construction=_WC_CAVITY,
         wall_insulation_type=4,
-        wall_thickness_measured=False,
+        # Summary §7 lodges Wall Thickness 380 mm explicitly; matches mapper.
+        wall_thickness_measured=True,
         party_wall_construction=0,  # "Unable to determine" → u_party_wall = 0.25
         sap_floor_dimensions=[
             SapFloorDimension(
@@ -99,8 +113,16 @@ def build_epc() -> EpcPropertyData:
         # joist insulation 300mm (or ≈ 270mm row at 0.16). Pin 300mm.
         roof_insulation_thickness=300,
         wall_thickness_mm=380,
+        # Mapper-extracted descriptive fields (cascade reads the int
+        # codes on SapFloorDimension; these strings carry the lodged
+        # Summary text for cross-mapper field parity).
+        floor_type="Ground floor",
+        floor_construction_type="Suspended timber",
+        floor_insulation_type_str="As built",
+        floor_u_value_known=False,
+        roof_insulation_location="Joists",
     )
-    return make_minimal_sap10_epc(
+    epc = make_minimal_sap10_epc(
         total_floor_area_m2=77.58,
         country_code="ENG",
         postcode="bd3 9DR",
@@ -116,12 +138,29 @@ def build_epc() -> EpcPropertyData:
         percent_draughtproofed=100,
         low_energy_fixed_lighting_bulbs_count=SECTION_5_BULB_COUNT_LEL,
         sap_windows=list(SECTION_6_VERTICAL_WINDOWS),
+        blocked_chimneys_count=0,
+        dwelling_type="Mid-Terrace house",
+        built_form="Mid-Terrace",
+        property_type="House",
         sap_ventilation=SapVentilation(
             extract_fans_count=2,
             sheltered_sides=2,
             has_suspended_timber_floor=True,
             suspended_timber_floor_sealed=False,
             has_draught_lobby=False,
+            # SAP10.2 §2 — explicit zero counts match the mapper, which
+            # parses the Summary's "No. of <flue>" rows. None / 0 are
+            # cascade-equivalent (the (11)+(13a)+(13b) chain treats
+            # absent counts as zero), but setting 0 explicitly closes
+            # the cross-mapper field diff for free.
+            open_flues_count=0,
+            closed_flues_count=0,
+            boiler_flues_count=0,
+            other_flues_count=0,
+            passive_vents_count=0,
+            flueless_gas_fires_count=0,
+            draught_lobby=True,
+            pressure_test="Not available",
         ),
         sap_heating=make_sap_heating(
             main_heating_details=[
@@ -134,6 +173,27 @@ def build_epc() -> EpcPropertyData:
             number_baths=0,  # PDF: Total number of baths in property = 0
         ),
     )
+    # Top-level cert-lodgement booleans / counts the Elmhurst mapper
+    # surfaces from the Summary PDF but `make_minimal_sap10_epc` doesn't
+    # expose as kwargs. Set post-construction (dataclass is non-frozen).
+    epc.has_conservatory = False
+    epc.any_unheated_rooms = False
+    epc.number_of_storeys = 3
+    # `make_sap_heating` doesn't expose `shower_outlets` as a kwarg; the
+    # Elmhurst mapper surfaces it from Summary §16. Setting here for
+    # cross-mapper field parity. Cascade-equivalent: a non-electric
+    # mixer outlet with no WWHRS is what Appendix J's flow-rate back-
+    # solve already assumes for this fixture (see fixture's
+    # MIXER_SHOWER_FLOW_RATES_L_PER_MIN = (7.0,) for 1 mixer outlet).
+    epc.sap_heating.shower_outlets = ShowerOutlets(
+        shower_outlet=ShowerOutlet(shower_outlet_type="Non-electric shower"),
+    )
+    # Summary §14 "Heat pump age: Unknown" — surfaced by the Elmhurst
+    # mapper as the str dual-encoding that internal_gains.py reads.
+    # `make_main_heating_detail` doesn't expose the str kwarg, so set
+    # here post-construction for cross-mapper field parity.
+    epc.sap_heating.main_heating_details[0].central_heating_pump_age_str = "Unknown"
+    return epc
 
 
 # ============================================================================