diff --git a/.idea/Model.iml b/.idea/Model.iml
index b03b31b1..05b9012b 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>
 </module>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index ca0e1cd9..3b05c6ac 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <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/db/models/materials.py b/backend/app/db/models/materials.py
new file mode 100644
index 00000000..4c4a8a09
--- /dev/null
+++ b/backend/app/db/models/materials.py
@@ -0,0 +1,51 @@
+import enum
+
+from sqlalchemy import Column, Integer, String, Float, Enum, TIMESTAMP
+from sqlalchemy.orm import declarative_base
+from sqlalchemy.sql import func
+
+Base = declarative_base()
+
+
+class MaterialType(enum.Enum):
+    suspended_floor_insulation = "suspended_floor_insulation"
+    solid_floor_insulation = "solid_floor_insulation"
+    external_wall_insulation = "external_wall_insulation"
+    internal_wall_insulation = "internal_wall_insulation"
+
+
+class DepthUnit(enum.Enum):
+    mm = "mm"
+
+
+class CostUnit(enum.Enum):
+    gbp_sq_meter = "gbp_sq_meter"
+
+
+class RValueUnit(enum.Enum):
+    square_meter_kelvin_per_watt = "square_meter_kelvin_per_watt"
+
+
+class ThermalConductivityUnit(enum.Enum):
+    watt_per_meter_kelvin = "watt_per_meter_kelvin"
+
+
+class Material(Base):
+    __tablename__ = 'material'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    type = Column(Enum(MaterialType, values_callable=lambda x: [e.value for e in x]), nullable=False)
+    description = Column(String, nullable=False)
+    depths = Column(String)  # You may want to use a specific JSON type depending on the database
+    depth_unit = Column(Enum(DepthUnit, values_callable=lambda x: [e.value for e in x]), nullable=False)
+    cost = Column(Float)
+    cost_unit = Column(Enum(CostUnit, values_callable=lambda x: [e.value for e in x]), nullable=False)
+    r_value_per_mm = Column(Float)
+    r_value_unit = Column(Enum(RValueUnit, values_callable=lambda x: [e.value for e in x]), nullable=False)
+    thermal_conductivity = Column(Float)
+    thermal_conductivity_unit = Column(
+        Enum(ThermalConductivityUnit, values_callable=lambda x: [e.value for e in x]),
+        nullable=False
+    )
+    link = Column(String)
+    created_at = Column(TIMESTAMP, nullable=False, server_default=func.now())
diff --git a/backend/app/plan/router.py b/backend/app/plan/router.py
index f06ca2ed..c119c79e 100644
--- a/backend/app/plan/router.py
+++ b/backend/app/plan/router.py
@@ -155,11 +155,17 @@ async def trigger_plan(body: PlanTriggerRequest):
     # The materials data could be cached or local so we don't need to make
     # consistent requrests to the backend for
     # the same data
+    # TODO: It might not be the best choice to store the materials data in a database table since thi
+    #       table probably won't be very large and won't be updated that often. It might be better to
+    #       store this data in s3 load it into memory when the app starts up. We will test this
     materials_by_type = get_materials(materials)
 
     logger.info("Getting components and properties recommendations")
-    recommendations = []
+
     for property_id, p in enumerate(input_properties):
+
+        property_recommendations = []
+
         # For each property, classiy floor area decide
         total_floor_area_group_decile = classify_decile_newvalues(
             decile_boundaries=floors_decile_data["decile_boundaries"],
@@ -191,7 +197,7 @@ async def trigger_plan(body: PlanTriggerRequest):
         for rec in floor_recommender.recommendations:
             rec["property_id"] = property_id
 
-        recommendations.extend(floor_recommender.recommendations)
+        property_recommendations.extend(floor_recommender.recommendations)
 
         # Wall recommendations
         # We would make this u-value query directly to the database
@@ -223,7 +229,10 @@ async def trigger_plan(body: PlanTriggerRequest):
         for rec in wall_recomendations.recommendations:
             rec["property_id"] = property_id
 
-        recommendations.extend(wall_recomendations.recommendations)
+        property_recommendations.extend(wall_recomendations.recommendations)
+
+        if property_recommendations:
+            blah
 
     # Once we're done, we'll store:
     # 1) the property data
diff --git a/model_data/simulation_system/app.py b/model_data/simulation_system/app.py
index 545fae16..2875925f 100644
--- a/model_data/simulation_system/app.py
+++ b/model_data/simulation_system/app.py
@@ -237,6 +237,7 @@ def app():
                         # Clean using averages
 
                         avgs = iterative_filtering(cleaning_averages, property_data)
+                        # TODO: Should probably do a mean/median?
                         field_value = avgs[field].iloc[0]
 
                         if pd.isnull(field_value):
@@ -281,6 +282,7 @@ def app():
                 rdsap_change = ending_record[RDSAP_RESPONSE] - starting_record[RDSAP_RESPONSE]
                 heat_demand_change = ending_record[HEAT_DEMAND_RESPONSE] - starting_record[HEAT_DEMAND_RESPONSE]
 
+                # TODO: Should this be <= 0?
                 if rdsap_change == 0:
                     # Assumption: We aren't interested in records that exhibit no change
                     continue