Allow empty roof description

model_data/epc_attributes/RoofAttributes.py

@@ -16,7 +16,7 @@ class RoofAttributes(BaseUtility):
         self.description: str = description.lower()
         self.nodata = not description or description in self.DATA_ANOMALY_MATCHES
 
-        if not description or not any(
+        if not self.nodata and not any(
             rt in self.description for rt in self.ROOF_TYPES + self.DWELLING_ABOVE + ["average thermal transmittance"]
         ):
             raise ValueError('Invalid description')

model_data/tests/test_roof_attributes.py

@@ -22,8 +22,8 @@ class TestRoofAttributes:
         assert floor_attr.description == valid_description.lower()
 
         # Test initialization with an empty description
-        with pytest.raises(ValueError):
-            RoofAttributes('')
+        ra = RoofAttributes('')
+        assert ra.nodata
 
         with pytest.raises(ValueError):
             RoofAttributes('description without keywords')
@@ -85,11 +85,13 @@ class TestRoofAttributes:
             assert result[k] == expected_output[k]
 
     def test_clean_roof_invalid(self):
-        with pytest.raises(ValueError):
-            RoofAttributes('').process()
         with pytest.raises(ValueError):
             RoofAttributes('nonsense string').process()
 
+    def test_clean_roof_no_description(self):
+        roof = RoofAttributes('').process()
+        assert roof == {}
+
     def test_clean_roof_edge_cases(self):
         # Insulation thickness edge case
         assert RoofAttributes('Pitched, 99999 mm loft insulation').process()['insulation_thickness'] == "99999"