From f68798818029f4578e71616489a57a8ad0a80193 Mon Sep 17 00:00:00 2001
From: Khalim Conn-Kowlessar <kconnkowlessar@gmail.com>
Date: Sun, 22 Jun 2025 17:11:45 +0100
Subject: [PATCH] Adding logic for a heat pump when the property is large
 enough and handling an edge case for dual heating

---
 backend/Property.py                   |  7 +++++++
 backend/app/assumptions.py            |  3 +++
 recommendations/Costs.py              |  4 ++--
 recommendations/HeatingRecommender.py | 14 ++++++++++++++
 sfr/principal_pitch/1_prepare_data.py |  3 ++-
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/backend/Property.py b/backend/Property.py
index 91c1265a..5b241bdc 100644
--- a/backend/Property.py
+++ b/backend/Property.py
@@ -1233,6 +1233,13 @@ class Property:
         if "air_source_heat_pump" not in measures:
             return False
 
+        # If we have a house over a floor area threshold, we recommend an ASHP
+        if (
+            self.data["property-type"] in ["House", "Bungalow"] and
+            self.floor_area > assumptions.ASHP_FLOOR_AREA_THRESHOLD
+        ):
+            return True
+
         suitable_house = self.data["property-type"] == "House" and self.data["built-form"] in [
             "Detached", "Semi-Detached", "End-Terrace",
         ]
diff --git a/backend/app/assumptions.py b/backend/app/assumptions.py
index f1090ef3..95271903 100644
--- a/backend/app/assumptions.py
+++ b/backend/app/assumptions.py
@@ -65,3 +65,6 @@ DESCRIPTIONS_TO_FUEL_TYPES = {
 measures_needing_ventilation = [
     "internal_wall_insulation", "external_wall_insulation", "cavity_wall_insulation"
 ]
+
+# If we have a property beyond this size, we assume it's likely large enough to have an ASHP
+ASHP_FLOOR_AREA_THRESHOLD = 120  # m2
diff --git a/recommendations/Costs.py b/recommendations/Costs.py
index 96eb5d0e..ee384b22 100644
--- a/recommendations/Costs.py
+++ b/recommendations/Costs.py
@@ -871,10 +871,10 @@ class Costs:
 
         if needs_cylinder:
             # 1000 is the cost of a new hot water cylinder
-            total_cost = 1200 * number_heated_rooms + 1000
+            total_cost = 1300 * number_heated_rooms + 1000
         else:
             # 500 is the cost of a dual immersion heater - a rough estimate
-            total_cost = 1200 * number_heated_rooms + 500
+            total_cost = 1300 * number_heated_rooms + 500
         subtotal_before_vat = total_cost / (1 + self.VAT_RATE)
         vat = total_cost - subtotal_before_vat
 
diff --git a/recommendations/HeatingRecommender.py b/recommendations/HeatingRecommender.py
index a776047b..9c44fe4a 100644
--- a/recommendations/HeatingRecommender.py
+++ b/recommendations/HeatingRecommender.py
@@ -61,6 +61,19 @@ class HeatingRecommender:
         'Electric underfloor heating, electric storage heaters': {
             # For this, we would recommend a heat pump
             "dual": None
+        },
+        "Room heaters, electric, boiler and radiators, mains gas": {
+            "hhr": {
+                "mainheating_description": "Electric storage heaters, radiators",
+                "recommendation_description": "Install high heat retention electric storage heaters.",
+                "controls_prefix": ""
+            },
+            "boiler": {
+                "mainheating_description": "Boiler and radiators, mains gas",
+                "recommendation_description": "Upgrade to a new condensing boiler.",
+                "controls_suffix": ""
+            },
+            "dual": None
         }
     }
 
@@ -932,6 +945,7 @@ class HeatingRecommender:
             return recommendations
 
         self.heating_recommendations.extend(recommendations)
+        return None
 
     @staticmethod
     def estimate_boiler_size(property_type, built_form, floor_area, floor_height, num_heated_rooms):
diff --git a/sfr/principal_pitch/1_prepare_data.py b/sfr/principal_pitch/1_prepare_data.py
index 8e799b9e..43002b88 100644
--- a/sfr/principal_pitch/1_prepare_data.py
+++ b/sfr/principal_pitch/1_prepare_data.py
@@ -71,6 +71,7 @@ body = {
     "ashp_cop": 3.5,
     # This is new - when optimising, we drop scores by a few points to account for SAP 10
     "simulate_sap_10": True,
-    "exclusions": ["external_wall_insulation"]
+    "exclusions": ["external_wall_insulation"],
+    "required_measures": ["cavity_wall_insulation", "loft_insulation"]
 }
 print(body)