diff --git a/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000490.py b/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000490.py
index 98b86231..54daf497 100644
--- a/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000490.py
+++ b/packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000490.py
@@ -359,12 +359,30 @@ LINE_73_M_TOTAL_INTERNAL_GAINS_W: tuple[float, ...] = (
 # ============================================================================
 # §6 Solar gains — cert-derived inputs + expected outputs
 # ============================================================================
-# 3 wall windows: NE 0.81, SE 5.52, NW 2.70 — all DG pre-2002 / PVC / 12 mm
-# with manufacturer g⊥=0.76. No roof windows, no rooflights.
+# 6 wall windows mirroring the Summary §11 1:1, matching the Elmhurst
+# mapper's per-row extraction. All DG pre-2002 / PVC / 12 mm with
+# manufacturer g⊥=0.76 / U=2.8 — single glazing-type group, per-bp
+# totals preserved (cascade-equivalent):
+#   Main NW (orient=8): 2.70 m² split 1.26 + 1.44 (2 rows)
+#   Main NE (orient=2): 0.81 m² (1 row)
+#   Ext1 SE (orient=4): 5.52 m² split 1.92 + 2.16 + 1.44 (3 rows)
+# No roof windows, no rooflights.
 SECTION_6_VERTICAL_WINDOWS: tuple[SapWindow, ...] = (
-    make_window(orientation=2, width=0.81, height=1.0, solar_transmittance=0.76),
-    make_window(orientation=4, width=5.52, height=1.0, solar_transmittance=0.76),
-    make_window(orientation=8, width=2.70, height=1.0, solar_transmittance=0.76),
+    # Windows on Main — NW (orient=8)
+    make_window(orientation=8, width=1.26, height=1.0, solar_transmittance=0.76,
+                u_value=2.8, window_location="Main"),
+    make_window(orientation=8, width=1.44, height=1.0, solar_transmittance=0.76,
+                u_value=2.8, window_location="Main"),
+    # Window on Main — NE (orient=2)
+    make_window(orientation=2, width=0.81, height=1.0, solar_transmittance=0.76,
+                u_value=2.8, window_location="Main"),
+    # Windows on Ext1 — SE (orient=4)
+    make_window(orientation=4, width=1.92, height=1.0, solar_transmittance=0.76,
+                u_value=2.8, window_location="1st Extension"),
+    make_window(orientation=4, width=2.16, height=1.0, solar_transmittance=0.76,
+                u_value=2.8, window_location="1st Extension"),
+    make_window(orientation=4, width=1.44, height=1.0, solar_transmittance=0.76,
+                u_value=2.8, window_location="1st Extension"),
 )
 SECTION_6_ROOF_WINDOWS: tuple[RoofWindowInput, ...] = ()
 SECTION_6_ROOFLIGHTS: tuple[RooflightInput, ...] = ()