diff --git a/model_data/recommendations/WallRecommendations.py b/model_data/recommendations/WallRecommendations.py
index c447288d..47dc99d6 100644
--- a/model_data/recommendations/WallRecommendations.py
+++ b/model_data/recommendations/WallRecommendations.py
@@ -187,6 +187,9 @@ wall_parts = external_wall_insulation_parts + internal_wall_insulation_parts
 
 class WallRecommendations(BaseUtility):
     YEAR_WALLS_BUILT_WITH_INSULATION = 1990
+    # After 1930, Solid brick walls became less populate and instead, cavity walls became a
+    # more popular choice
+    YEARS_CAVITY_WALLS_BEGAN = 1930
     U_VALUE_UNIT = 'w/m-¦k'
     # TODO: REVIEW THESE FIGURES: RETROFIT ACADEMY COUSE INDICATED THAT IT SHOULD BE 0.3
     BUILDING_REGULATIONS_PART_L_MAX_U_VALUE = 0.18
diff --git a/model_data/tests/test_data/input_properties.pkl b/model_data/tests/test_data/input_properties.pkl
new file mode 100644
index 00000000..6fd5b797
Binary files /dev/null and b/model_data/tests/test_data/input_properties.pkl differ
diff --git a/model_data/tests/test_wall_recommendations.py b/model_data/tests/test_wall_recommendations.py
new file mode 100644
index 00000000..ab98e5ba
--- /dev/null
+++ b/model_data/tests/test_wall_recommendations.py
@@ -0,0 +1,25 @@
+import os
+import pytest
+import pickle
+from model_data.recommendations.WallRecommendations import WallRecommendations
+
+
+class TestWallRecommendations:
+
+    @pytest.fixture
+    def input_properties(self):
+        with open(
+            os.path.abspath(os.path.dirname(__file__)) + "/test_data/input_properties.pkl", "rb"
+        ) as f:
+            return pickle.load(f)
+
+    @pytest.fixture
+    def uvalue_estimates(self):
+        with open(
+            os.path.abspath(os.path.dirname(__file__)) + "/test_data/uvalue_estimates_walls.pkl", "rb"
+        ) as f:
+            return pickle.load(f)
+
+    def test_nothing(self, input_properties, uvalue_estimates):
+        assert input_properties
+        assert uvalue_estimates