diff --git a/tests/domain/epc/test_roof_party_ceiling_guard.py b/tests/domain/epc/test_roof_party_ceiling_guard.py
index 3c155f23c..9152b655e 100644
--- a/tests/domain/epc/test_roof_party_ceiling_guard.py
+++ b/tests/domain/epc/test_roof_party_ceiling_guard.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 from domain.epc.property_overrides.roof_type import RoofType
 from domain.epc.property_overrides.roof_party_ceiling_guard import (
     roof_party_ceiling_guard,
@@ -16,3 +18,25 @@ def test_party_ceiling_marker_with_a_trailing_depth_resolves_to_the_party_ceilin
 
     # Assert — it is a party ceiling (~0 heat loss), not a Pitched roof.
     assert result is RoofType.ADJACENT_ANOTHER_DWELLING_ABOVE
+
+
+@pytest.mark.parametrize(
+    ("description", "expected"),
+    [
+        ("same dwelling above: unknown", RoofType.ADJACENT_SAME_DWELLING_ABOVE),
+        ("other premises above", RoofType.ADJACENT_OTHER_PREMISES_ABOVE),
+        ("another premises above: 150mm", RoofType.ADJACENT_ANOTHER_PREMISES_ABOVE),
+        # the unspaced source form and the "Another Premises Above" member value
+        # both normalise to the same marker.
+        ("Another Premises Above", RoofType.ADJACENT_ANOTHER_PREMISES_ABOVE),
+        ("samedwellingabove: 300mm", RoofType.ADJACENT_SAME_DWELLING_ABOVE),
+    ],
+)
+def test_every_party_ceiling_marker_variant_resolves_to_its_member(
+    description: str, expected: RoofType
+) -> None:
+    # Act
+    result = roof_party_ceiling_guard(description)
+
+    # Assert
+    assert result is expected