ammended system change costs for first time central heating

recommendations/Costs.py

@@ -83,6 +83,14 @@ CONVENTIONAL_BOILER_COSTS = {
 ROOM_HEATER_REMOVAL_COST = 120
 ROOM_HEATER_REMOVAL_LABOUR_HOURS = 3
 
+# This is a cost quoted by Jim for a system flush - existig system will run more efficiently
+SYSTEM_FLUSH_COST = 250
+
+SINGLE_RADIATOR_COST = 150
+DOUBLE_RADIATOR_COST = 300
+FLUE_COST = 600
+PIPEWORK_COST = 750  # Min cost is £500
+
 
 class Costs:
     """
@@ -1126,9 +1134,45 @@ class Costs:
             "labour_days": np.ceil(removal_labour_hours / 8),
         }
 
-    def boiler(self, is_combi, size, exising_room_heaters, n_heated_rooms):
+    @staticmethod
+    def _estimate_n_radiators(number_habitable_rooms, total_floor_area, property_type, built_form):
+        # Base number of radiators: one per habitable room
+        base_radiators = number_habitable_rooms
+
+        # Additional radiators for non-habitable essential areas (e.g., kitchens, hallways)
+        additional_radiators = 3  # Initial assumption
+
+        # Adjust additional radiators based on property type
+        if property_type == 'Flat':
+            additional_radiators -= 1  # Flats may need fewer radiators due to less exposure
+        elif property_type in ['House', 'Bungalow', 'Maisonette']:
+            # Multiple floors in Maisonette may require additional heating points
+            additional_radiators += 2  # Houses and bungalows might need more due to greater exposure
+        else:
+            raise Exception("Invalid property type")
+
+        # Adjust total radiator needs based on built form
+        form_factor = {
+            'Mid-Terrace': 0.95,
+            'Semi-Detached': 1.05,
+            'Detached': 1.25,
+            'End-Terrace': 1.05
+        }
+
+        # Calculate total heating power needed and number of radiators based on standard output
+        total_heating_power_required = total_floor_area * 80  # Watts per square meter
+        radiator_output = 1000  # Average wattage per radiator
+        total_radiators_based_on_power = (total_heating_power_required / radiator_output) * form_factor[built_form]
+
+        # Final estimation taking the higher of calculated needs or base room count
+        estimated_radiators = max(total_radiators_based_on_power, base_radiators + additional_radiators)
+        return round(estimated_radiators)
+
+    def boiler(self, is_combi, size, exising_room_heaters, system_change, n_heated_rooms, n_rooms):
         """
         Based on a basic estimate of median value £2600 to install a low carbon combi boiler
+        First time central heating vosts can als be found here:
+        https://www.checkatrade.com/blog/cost-guides/central-heating-installation-cost/
         :return:
         """
 
@@ -1137,11 +1181,11 @@ class Costs:
         # We now need to estimate the cost of the works
         labour_days = 2
         labour_hours = labour_days * 8
-        labour_rate = 500
+        labour_rate = 300
 
         # Average cost of installation is 1 (maybe 2days) at £300 per day
         # https://www.checkatrade.com/blog/cost-guides/new-boiler-cost/
-        # To be pessimistic, assume 2 days work and £500 day rate
+        # To be pessimistic, assume 2 days work
         labour_cost = labour_rate * self.labour_adjustment_factor * labour_days
         # Add contingency and preliminaries
         labour_cost = labour_cost * (1 + self.CONTINGENCY + self.PRELIMINARIES)
@@ -1161,6 +1205,28 @@ class Costs:
             subtotal_before_vat += removal_costing["subtotal"]
             labour_hours += removal_costing["labour_hours"]
             labour_days += removal_costing["labour_days"]
+            vat += removal_costing["vat"]
+
+        if system_change:
+            # We need the cost of radiators
+            n_radiators = self._estimate_n_radiators(
+                number_habitable_rooms=n_rooms,
+                total_floor_area=self.property.floor_area,
+                property_type=self.property.data["property-type"],
+                built_form=self.property.data["built-form"]
+            )
+
+            additionals_labour_cost = labour_rate * self.labour_adjustment_factor
+            radiator_cost = DOUBLE_RADIATOR_COST * n_radiators
+            system_change_cost = radiator_cost + FLUE_COST + PIPEWORK_COST + additionals_labour_cost
+            system_change_cost_before_vat = system_change_cost / (1 + self.VAT_RATE)
+            system_change_vat = system_change_cost - system_change_cost_before_vat
+            # We add an extra labour day for the system change
+            labour_days += 1
+            labour_hours += 8
+            total_cost += system_change_cost
+            subtotal_before_vat += system_change_cost_before_vat
+            vat += system_change_vat
 
         return {
             "total": total_cost,

recommendations/HeatingRecommender.py

@@ -18,6 +18,11 @@ class HeatingRecommender:
         self.recommendations = []
 
     def recommend(self, phase=0):
+
+        # TODO: We could have a system flush recommendation for an existing boiler, where there is no need to replace
+        #       the boiler, but instead flushing the system will make it run more efficiently. There is a cost for this
+        #       in the Costs class, stored as SYSTEM_FLUSH_COST
+
         self.recommendations = []
         # This first iteration of the recommender will provide very basic recommendation
         # We recommend heating controls based on the main heating system
@@ -361,7 +366,9 @@ class HeatingRecommender:
                 is_combi=is_combi,
                 size=f"{boiler_size}kw",
                 exising_room_heaters=exising_room_heaters,
-                n_heated_rooms=self.property.data["number-heated-rooms"]
+                system_change=system_change,
+                n_heated_rooms=self.property.data["number-heated-rooms"],
+                n_rooms=self.property.number_of_rooms
             )
 
             is_override = "heating" in self.property.override