diff --git a/tests/backend/app/modelling/test_property_filters.py b/tests/backend/app/modelling/test_property_filters.py
index 223696dd5..7f4a0f255 100644
--- a/tests/backend/app/modelling/test_property_filters.py
+++ b/tests/backend/app/modelling/test_property_filters.py
@@ -258,6 +258,35 @@ def test_unknown_is_a_selectable_property_type_bucket(db_engine: Engine) -> None
     assert [p.property_id for p in resolved] == [unknowable]
 
 
+def test_built_form_filter_resolves_with_the_same_precedence(
+    db_engine: Engine,
+) -> None:
+    # arrange — both lodged as code 4 (Mid-Terrace); one overridden to Detached
+    with Session(db_engine) as session:
+        overridden = _seed_property(session, portfolio_id=814)
+        _seed_epc(session, property_id=overridden, built_form="4")
+        _seed_override(
+            session,
+            property_id=overridden,
+            component="built_form_type",
+            value="Detached",
+        )
+        mid_terrace = _seed_property(session, portfolio_id=814)
+        _seed_epc(session, property_id=mid_terrace, built_form="4")
+        semi = _seed_property(session, portfolio_id=814)
+        _seed_epc(session, property_id=semi, built_form="2")
+
+        # act
+        resolved = resolve_filtered_property_ids(
+            session,
+            portfolio_id=814,
+            filters=PropertyGroupFilters(built_forms=["Detached", "Mid-Terrace"]),
+        )
+
+    # assert — the override wins for one; the code maps for the other
+    assert [p.property_id for p in resolved] == [overridden, mid_terrace]
+
+
 def test_postcode_filter_matches_exactly(db_engine: Engine) -> None:
     # arrange
     with Session(db_engine) as session: