diff --git a/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000516.py b/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000516.py
index dabc4f70..b4c50656 100644
--- a/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000516.py
+++ b/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000516.py
@@ -29,6 +29,7 @@ from datatypes.epc.domain.epc_property_data import (
     SapBuildingPart,
     SapFloorDimension,
     SapRoomInRoof,
+    SapRoomInRoofSurface,
     SapVentilation,
     SapWindow,
 )
@@ -67,6 +68,11 @@ def build_epc() -> EpcPropertyData:
                 total_floor_area_m2=35.76,
                 party_wall_length_m=18.14, heat_loss_perimeter_m=7.89,
                 floor=0,
+                # 000516 line: "Exposed floor Main 35.76 × U=1.20" (28b)
+                # — the Main ground floor sits over an unheated space
+                # (passageway / over-garage), not earth. Routes via
+                # Table 20 (`u_exposed_floor`) to U=1.20.
+                is_exposed_floor=True,
             ),
             SapFloorDimension(
                 room_height_m=3.00,  # = 2.75 internal + 0.25 floor structure
@@ -77,7 +83,39 @@ def build_epc() -> EpcPropertyData:
         ],
         sap_room_in_roof=SapRoomInRoof(
             floor_area=19.02, construction_age_band="A",
+            # 000516 §3.10 RR detailed surfaces: 2 stud walls @ 100mm
+            # (Table 17 col 3a → 0.36), 2 slopes uninsulated (col 1a
+            # "none" → 2.30), 1 flat ceiling uninsulated (col 2a "none"
+            # → 2.30), 2 gable walls treated as party at U=0.25.
+            detailed_surfaces=[
+                SapRoomInRoofSurface(
+                    kind="flat_ceiling", area_m2=3.56,
+                    insulation_thickness_mm=0,
+                ),
+                SapRoomInRoofSurface(
+                    kind="stud_wall", area_m2=3.88,
+                    insulation_thickness_mm=100, insulation_type="mineral_wool",
+                ),
+                SapRoomInRoofSurface(
+                    kind="stud_wall", area_m2=3.88,
+                    insulation_thickness_mm=100, insulation_type="mineral_wool",
+                ),
+                SapRoomInRoofSurface(
+                    kind="slope", area_m2=6.41,
+                    insulation_thickness_mm=0,
+                ),
+                SapRoomInRoofSurface(
+                    kind="slope", area_m2=6.41,
+                    insulation_thickness_mm=0,
+                ),
+                SapRoomInRoofSurface(kind="gable_wall", area_m2=13.11),
+                SapRoomInRoofSurface(kind="gable_wall", area_m2=13.11),
+            ],
         ),
+        # 000516 line: "External roof Main 16.74 - 1.18 = 15.56 × U=2.30"
+        # (30) — uninsulated storey-below roof. Lodge thickness=0 so the
+        # u_roof cascade picks the Table 16 "none" row.
+        roof_insulation_thickness=0,
         wall_thickness_mm=400,
     )
     return make_minimal_sap10_epc(
@@ -86,7 +124,10 @@ def build_epc() -> EpcPropertyData:
         sap_building_parts=[main],
         habitable_rooms_count=3,
         heated_rooms_count=3,
-        door_count=1,
+        # 000516 PDF (26) lodges total door area 3.70 m² = 2 × _DEFAULT_DOOR_
+        # AREA_M2 (1.85). Same as 000477/000480 — single worksheet entry
+        # but the area resolves to 2 physical doors.
+        door_count=2,
         percent_draughtproofed=75,
         low_energy_fixed_lighting_bulbs_count=SECTION_5_BULB_COUNT_LEL,
         sap_windows=list(SECTION_6_VERTICAL_WINDOWS),