diff --git a/B08_Quantity/B08_Quantity_Engine_ObservedUnit.py b/B08_Quantity/B08_Quantity_Engine_ObservedUnit.py
index a29c376f..aab337de 100644
--- a/B08_Quantity/B08_Quantity_Engine_ObservedUnit.py
+++ b/B08_Quantity/B08_Quantity_Engine_ObservedUnit.py
@@ -283,8 +283,16 @@ def expand_observed(
     source_key = str(found.get("source") or "")
     options = structure.get("options") or {}
     components: list[dict[str, Any]] = []
+    blocked: list[str] = []
     for item in found.get("components") or []:
         note = str(item.get("basis_note") or "")
+        if not item.get("destination"):
+            # ⛔ 갈 곳 기본값 금지(명세 13장) — 종전 `or "material"` 은 줄이 늘 때 조용히 자재로 샘.
+            blocked.append(
+                f"「{item['name']}」 관측 원단위 줄에 갈 곳이 없어 물량을 어느 축에도 안 보냄"
+                " — 표(`structure_unit_observed`)에 적을 것(명세 13장 갈 곳 기본값 금지)"
+            )
+            continue
         weep = (
             weep_component(found, options, scale, scale_note)
             if item["name"] == "물구멍관"
@@ -298,7 +306,7 @@ def expand_observed(
                 "name": item["name"],
                 "unit": item["unit"],
                 "amount": float(item["amount"]) * scale,
-                "destination": item.get("destination") or "material",
+                "destination": item["destination"],
                 # 근거를 값 옆에 붙인다 — 관측값임을 화면·인계에서 바로 알아야 한다.
                 "basis": f"관측 원단위 {item['amount']:g}/{found.get('unit')} × {scale_note}"
                 + (f" ({note})" if note else ""),
@@ -308,7 +316,7 @@ def expand_observed(
                 "spec": str(item.get("spec") or ""),
             }
         )
-    notes = [f"관측 원단위 적용 — {found.get('source_note') or source_key}"]
+    notes = [f"관측 원단위 적용 — {found.get('source_note') or source_key}", *blocked]
     # 줄에 붙은 사유(원문끼리 다름 등) — 구조물도 그림도 같은 글자를 씀.
     notes.extend(str(note) for note in found.get("notes") or [])
     earthwork_note = earthwork_missing_note(found)
diff --git a/resources/tester/test_b08_destination_no_default.py b/resources/tester/test_b08_destination_no_default.py
index e604b41a..67c4cd1c 100644
--- a/resources/tester/test_b08_destination_no_default.py
+++ b/resources/tester/test_b08_destination_no_default.py
@@ -53,3 +53,36 @@ def test_드러난_넷이_제자리로_감() -> None:
     sod, sod_notes = soil_guard({"form": "떼"})
     assert {c.name: c.destination for c in sod}["떼"] == "material"
     assert not [note for note in sod_notes if "갈 곳이 표" in note]
+
+
+def test_관측_원단위_줄도_갈_곳이_없으면_막히고_사유() -> None:
+    """관측 원단위 로더의 `destination or "material"` 도 같은 병 — 줄이 늘 때 바로 드러나게."""
+    from B08_Quantity.B08_Quantity_Engine_ObservedUnit import ObservedUnitTable, expand_observed
+
+    table = ObservedUnitTable(
+        entries=[
+            {
+                "type_id": "시험구조물",
+                "unit": "개소",
+                "components": [
+                    {"name": "콘크리트", "unit": "㎥", "amount": 1.0, "destination": "unit_price"},
+                    {"name": "새자재", "unit": "㎥", "amount": 2.0},
+                ],
+            }
+        ]
+    )
+    components, notes = expand_observed("시험구조물", {}, {"options": {}}, table)
+    assert [c["name"] for c in components] == ["콘크리트"]
+    assert any("새자재" in note and "기본값 금지" in note for note in notes)
+
+
+def test_관측_원단위_표의_전_줄에_갈_곳이_있음() -> None:
+    from B08_Quantity.B08_Quantity_Engine_ObservedUnit import load_observed_table
+
+    missing = [
+        (entry.get("type_id"), item.get("name"))
+        for entry in load_observed_table().entries
+        for item in entry.get("components") or []
+        if not item.get("destination")
+    ]
+    assert missing == []