diff --git a/.idea/Model.iml b/.idea/Model.iml
index b0f9c00d..4413bb06 100644
--- a/.idea/Model.iml
+++ b/.idea/Model.iml
@@ -7,7 +7,7 @@
       <sourceFolder url="file://$MODULE_DIR$/open_uprn" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/recommendations" isTestSource="false" />
     </content>
-    <orderEntry type="jdk" jdkName="Python 3.10 (model_data)" jdkType="Python SDK" />
+    <orderEntry type="jdk" jdkName="Python 3.10 (backend)" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
   <component name="PyNamespacePackagesService">
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 1122b380..6f308057 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -3,7 +3,7 @@
   <component name="Black">
     <option name="sdkName" value="Python 3.10 (backend)" />
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.10 (model_data)" project-jdk-type="Python SDK" />
+  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.10 (backend)" project-jdk-type="Python SDK" />
   <component name="PythonCompatibilityInspectionAdvertiser">
     <option name="version" value="3" />
   </component>
diff --git a/backend/app/plan/router.py b/backend/app/plan/router.py
index 952d4982..a284e50b 100644
--- a/backend/app/plan/router.py
+++ b/backend/app/plan/router.py
@@ -544,9 +544,7 @@ async def trigger_plan(body: PlanTriggerRequest):
 
                     valuations = PropertyValuation.estimate(property_instance=p, target_epc=new_epc)
 
-                    property_valuation_increases.append(
-                        valuations["average_increased_value"] - valuations["current_value"]
-                    )
+                    property_valuation_increases.append(valuations["average_increase"])
 
                 # Commit the session after each batch
                 session.commit()
diff --git a/backend/app/plan/utils.py b/backend/app/plan/utils.py
index 90042fa2..b82be297 100644
--- a/backend/app/plan/utils.py
+++ b/backend/app/plan/utils.py
@@ -178,10 +178,21 @@ def create_recommendation_scoring_data(
     if recommendation["type"] == "windows_glazing":
         scoring_dict["MULTI_GLAZE_PROPORTION_ENDING"] = 100
         scoring_dict["WINDOWS_ENERGY_EFF_ENDING"] = "Average"
-        if scoring_dict["glazing_type_ENDING"] in ["multiple", "double"]:
+
+        is_secondary_glazing = recommendation["is_secondary_glazing"]
+
+        if scoring_dict["glazing_type_ENDING"] == "multiple":
             pass
+        elif scoring_dict["glazing_type_ENDING"] == "single":
+            scoring_dict["glazing_type_ENDING"] = "secondary" if is_secondary_glazing else "double"
+        elif scoring_dict["glazing_type_ENDING"] == "double":
+            scoring_dict["glazing_type_ENDING"] = "multiple" if is_secondary_glazing else "double"
+        elif scoring_dict["glazing_type_ENDING"] == "secondary":
+            scoring_dict["glazing_type_ENDING"] = "secondary" if is_secondary_glazing else "multiple"
+        elif scoring_dict["glazing_type_ENDING"] in ["triple", "high performance"]:
+            scoring_dict["glazing_type_ENDING"] = "multiple"
         else:
-            raise NotImplementedError("Implement me")
+            raise ValueError("Invalid glazing type - implement me")
 
     if recommendation["type"] not in [
         "mechanical_ventilation", "sealing_open_fireplace", "low_energy_lighting",
diff --git a/backend/ml_models/Valuation.py b/backend/ml_models/Valuation.py
index f5a7e2bb..cdbbe698 100644
--- a/backend/ml_models/Valuation.py
+++ b/backend/ml_models/Valuation.py
@@ -93,7 +93,13 @@ class PropertyValuation:
         value = cls.UPRN_VALUE_LOOKUP.get(property_instance.uprn)
 
         if not value:
-            raise ValueError("Have not implemented valuation for this property")
+            return {
+                "current_value": None,
+                "lower_bound_increased_value": None,
+                "upper_bound_increased_value": None,
+                "average_increased_value": None,
+                "average_increase": None
+            }
 
         current_epc = property_instance.data["current-energy-rating"]
         # We get the spectrum of ratings between the current and target EPC
@@ -119,4 +125,5 @@ class PropertyValuation:
             "lower_bound_increased_value": value * (1 + min_increase),
             "upper_bound_increased_value": value * (1 + max_increase),
             "average_increased_value": value * (1 + avg_increase),
+            "average_increase": value * (1 + avg_increase) - value
         }
diff --git a/recommendations/WindowsRecommendations.py b/recommendations/WindowsRecommendations.py
index 6246fd95..b6ecd099 100644
--- a/recommendations/WindowsRecommendations.py
+++ b/recommendations/WindowsRecommendations.py
@@ -91,6 +91,7 @@ class WindowsRecommendations:
                 "starting_u_value": None,
                 "new_u_value": None,
                 "sap_points": None,
-                **cost_result
+                **cost_result,
+                "is_secondary_glazing": is_secondary_glazing
             }
         ]