wrote complete loft insulation recommendations

backend/app/plan/router.py

@@ -121,7 +121,7 @@ async def trigger_plan(body: PlanTriggerRequest):
 
         # TODO: Move this to a class. We probably want a Recommender class which takes the injects the optimisers
         #      in as a dependency and then the optimisers can take the input measures in as part of the setup() method
-
+        
         # import pickle
         # with open("input_properties.pickle", "rb") as f:
         #     input_properties = pickle.load(f)

recommendations/RoofRecommendations.py

@@ -18,6 +18,9 @@ class RoofRecommendations:
 
     DIMINISHING_RETURNS_U_VALUE = 0.14
 
+    # It is recommended that lofts should have at least 270mm of insulation
+    MINIMUM_LOFT_ISULATION_MM = 270
+
     def __init__(
         self,
         property_instance: Property,
@@ -41,7 +44,7 @@ class RoofRecommendations:
 
         # Building regulations part L recommend installing at least 270mm of insulation, however generally we
         # experience diminishing returns in terms of SAP once we go beyond around 150mm of insulation
-        if insulation_thickness < 270:
+        if insulation_thickness >= self.MINIMUM_LOFT_ISULATION_MM:
             return
 
         # If we have a u-value already, need to implement this
@@ -52,7 +55,7 @@ class RoofRecommendations:
 
         if self.property.roof["is_pitched"]:
             # We recommend loft insulation
-            self.recommend_loft_insulation(u_value)
+            self.recommend_loft_insulation(u_value, insulation_thickness)
             return
 
         raise NotImplementedError("Implement me")
@@ -61,10 +64,12 @@ class RoofRecommendations:
     def make_loft_insulation_description(material, depth):
         return f"Install {depth}{material['depth_unit']} of {material['description']}"
 
-    def recommend_loft_insulation(self, u_value):
+    def recommend_loft_insulation(self, u_value, insulation_thickness):
 
         """
         This method will recommend which insulation materials to use
+        :param u_value: U-value of the roof before any retrofit measures have been installed
+        :param insulation_thickness: Existing Insulation thickness of the loft
         :return:
         """
 
@@ -79,6 +84,10 @@ class RoofRecommendations:
         for material in loft_insulation_materials:
 
             for depth, cost_per_unit in zip(material["depths"], material["cost"]):
+                # We make sure we hit a depth of 270mm. We should factor in any existing insulation if the
+                # loft is already partially insulated
+                if (depth + insulation_thickness) < self.MINIMUM_LOFT_ISULATION_MM:
+                    continue
 
                 part_u_value = r_value_per_mm_to_u_value(depth, material["r_value_per_mm"])
 

recommendations/tests/test_roof_recommendations.py

@@ -13,6 +13,28 @@ loft_insulation_materials = [
     }
 ]
 
+loft_insulation_materials_50mm_existing = [
+    {
+        'id': 18, 'type': 'loft_insulation', 'description': 'Iso Spacesaver Mineral Wool insulation',
+        'depths': [220, 210], 'depth_unit': 'mm', 'cost': [9, 10], 'cost_unit': 'gbp_sq_meter',
+        'r_value_per_mm': 0.022727273, 'r_value_unit': 'square_meter_kelvin_per_watt',
+        'thermal_conductivity': 0.044, 'thermal_conductivity_unit': 'watt_per_meter_kelvin',
+        'link': 'https://flooringwarehousedirect.co.uk/product/isover-spacesaver-roll-100mm-x-1160mm-x-12-18m-14-13m2/',
+        'is_active': True
+    }
+]
+
+loft_insulation_materials_150mm_existing = [
+    {
+        'id': 18, 'type': 'loft_insulation', 'description': 'Iso Spacesaver Mineral Wool insulation',
+        'depths': [130, 119], 'depth_unit': 'mm', 'cost': [9, 10], 'cost_unit': 'gbp_sq_meter',
+        'r_value_per_mm': 0.022727273, 'r_value_unit': 'square_meter_kelvin_per_watt',
+        'thermal_conductivity': 0.044, 'thermal_conductivity_unit': 'watt_per_meter_kelvin',
+        'link': 'https://flooringwarehousedirect.co.uk/product/isover-spacesaver-roll-100mm-x-1160mm-x-12-18m-14-13m2/',
+        'is_active': True
+    }
+]
+
 
 class TestRoofRecommendations:
 
@@ -37,3 +59,136 @@ class TestRoofRecommendations:
         roof_recommender.recommend()
 
         assert len(roof_recommender.recommendations)
+
+    def test_loft_insulation_recommendation_50mm_insulation(self):
+        property_instance2 = Property(id=0, address1="fake", postcode="fake", epc_client=Mock())
+        property_instance2.age_band = "F"
+        property_instance2.floor_area = 100
+        property_instance2.roof = {
+            'original_description': 'Pitched, 50mm loft insulation (assumed)',
+            'clean_description': 'Pitched, 50mm loft insulation',
+            'thermal_transmittance': None,
+            'thermal_transmittance_unit': None,
+            'is_pitched': True, 'is_roof_room': False, 'is_loft': True, 'is_flat': False, 'is_thatched': False,
+            'is_at_rafters': False, 'is_assumed': True, 'has_dwelling_above': False, 'is_valid': True,
+            'insulation_thickness': '50', 'roof_thermal_transmittance': None, 'roof_insulation_thickness': 'none'
+        }
+
+        roof_recommender2 = RoofRecommendations(
+            property_instance=property_instance2, materials=loft_insulation_materials
+        )
+
+        assert not roof_recommender2.recommendations
+
+        roof_recommender2.recommend()
+
+        assert len(roof_recommender2.recommendations) == 1
+
+        assert roof_recommender2.recommendations[0]["cost"] == 900
+        assert roof_recommender2.recommendations[0]["new_u_value"] == 0.14
+        assert roof_recommender2.recommendations[0]["starting_u_value"] == 0.68
+
+        property_instance3 = Property(id=0, address1="fake", postcode="fake", epc_client=Mock())
+        property_instance3.age_band = "F"
+        property_instance3.floor_area = 100
+        property_instance3.roof = {
+            'original_description': 'Pitched, 50mm loft insulation (assumed)',
+            'clean_description': 'Pitched, 50mm loft insulation',
+            'thermal_transmittance': None,
+            'thermal_transmittance_unit': None,
+            'is_pitched': True, 'is_roof_room': False, 'is_loft': True, 'is_flat': False, 'is_thatched': False,
+            'is_at_rafters': False, 'is_assumed': True, 'has_dwelling_above': False, 'is_valid': True,
+            'insulation_thickness': '50', 'roof_thermal_transmittance': None, 'roof_insulation_thickness': 'none'
+        }
+
+        roof_recommender3 = RoofRecommendations(
+            property_instance=property_instance3, materials=loft_insulation_materials_50mm_existing
+        )
+
+        assert not roof_recommender3.recommendations
+
+        roof_recommender3.recommend()
+
+        # The 220mm insulation should be selected, not the 210
+        assert roof_recommender3.recommendations
+        assert len(roof_recommender3.recommendations) == 1
+        assert roof_recommender3.recommendations[0]["parts"][0]["depths"] == [220]
+
+    def test_loft_insulation_recommendation_150mm_insulation(self):
+        property_instance4 = Property(id=0, address1="fake", postcode="fake", epc_client=Mock())
+        property_instance4.age_band = "F"
+        property_instance4.floor_area = 100
+        property_instance4.roof = {
+            'original_description': 'Pitched, 150mm loft insulation (assumed)',
+            'clean_description': 'Pitched, 150mm loft insulation',
+            'thermal_transmittance': None,
+            'thermal_transmittance_unit': None,
+            'is_pitched': True, 'is_roof_room': False, 'is_loft': True, 'is_flat': False, 'is_thatched': False,
+            'is_at_rafters': False, 'is_assumed': True, 'has_dwelling_above': False, 'is_valid': True,
+            'insulation_thickness': '150', 'roof_thermal_transmittance': None, 'roof_insulation_thickness': 'none'
+        }
+
+        roof_recommender4 = RoofRecommendations(
+            property_instance=property_instance4, materials=loft_insulation_materials
+        )
+
+        assert not roof_recommender4.recommendations
+
+        roof_recommender4.recommend()
+
+        assert len(roof_recommender4.recommendations) == 1
+
+        assert roof_recommender4.recommendations[0]["cost"] == 900
+        assert roof_recommender4.recommendations[0]["new_u_value"] == 0.11
+        assert roof_recommender4.recommendations[0]["starting_u_value"] == 0.3
+
+        property_instance5 = Property(id=0, address1="fake", postcode="fake", epc_client=Mock())
+        property_instance5.age_band = "F"
+        property_instance5.floor_area = 100
+        property_instance5.roof = {
+            'original_description': 'Pitched, 150mm loft insulation (assumed)',
+            'clean_description': 'Pitched, 150mm loft insulation',
+            'thermal_transmittance': None,
+            'thermal_transmittance_unit': None,
+            'is_pitched': True, 'is_roof_room': False, 'is_loft': True, 'is_flat': False, 'is_thatched': False,
+            'is_at_rafters': False, 'is_assumed': True, 'has_dwelling_above': False, 'is_valid': True,
+            'insulation_thickness': '150', 'roof_thermal_transmittance': None, 'roof_insulation_thickness': 'none'
+        }
+
+        roof_recommender5 = RoofRecommendations(
+            property_instance=property_instance5, materials=loft_insulation_materials_150mm_existing
+        )
+
+        assert not roof_recommender5.recommendations
+
+        roof_recommender5.recommend()
+
+        # The 130mm insulation should be selected, not the 110
+        assert roof_recommender5.recommendations
+        assert len(roof_recommender5.recommendations) == 1
+        assert roof_recommender5.recommendations[0]["parts"][0]["depths"] == [130]
+
+    def test_loft_insulation_recommendation_270mm_insulation(self):
+        # We shouldn't recommend anything in this case
+        property_instance6 = Property(id=0, address1="fake", postcode="fake", epc_client=Mock())
+        property_instance6.age_band = "F"
+        property_instance6.floor_area = 100
+        property_instance6.roof = {
+            'original_description': 'Pitched, 270mm loft insulation (assumed)',
+            'clean_description': 'Pitched, 270mm loft insulation',
+            'thermal_transmittance': None,
+            'thermal_transmittance_unit': None,
+            'is_pitched': True, 'is_roof_room': False, 'is_loft': True, 'is_flat': False, 'is_thatched': False,
+            'is_at_rafters': False, 'is_assumed': True, 'has_dwelling_above': False, 'is_valid': True,
+            'insulation_thickness': '270', 'roof_thermal_transmittance': None, 'roof_insulation_thickness': 'none'
+        }
+
+        roof_recommender6 = RoofRecommendations(
+            property_instance=property_instance6, materials=loft_insulation_materials
+        )
+
+        assert not roof_recommender6.recommendations
+
+        roof_recommender6.recommend()
+
+        assert len(roof_recommender6.recommendations) == 0