diff --git a/model_data/recommendations/WallRecommendations.py b/model_data/recommendations/WallRecommendations.py
index f8ae1898..f50f4f36 100644
--- a/model_data/recommendations/WallRecommendations.py
+++ b/model_data/recommendations/WallRecommendations.py
@@ -15,77 +15,92 @@ external_wall_insulation_parts = [
         "depth_unit": "mm",
         "cost": None,
         "cost_unit": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
         "r_value_per_mm": 0.0278,
         "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": 0.036,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
     },
     {
+        # Example product
+        # https://www.insulationking.co.uk/products/polystyrene-eps70?variant=44156186558759
         "type": "external_wall_insulation",
         "description": "Expanded Polystyrene External Wall Insulation",
-        "depths": [],
+        "depths": [25, 50, 100, 125],
         "depth_unit": "mm",
         "cost": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
-        "u_value": None
+        "cost_unit": None,
+        "r_value_per_mm": 0.02703,
+        "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": 0.037,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
     },
     {
+        # Example product
+        # https://www.insulationshop.co/20mm_kooltherm_k5_external_wall_kingspan.html
         "type": "external_wall_insulation",
         "description": "Phenolic Foam External Wall Insulation",
-        "depths": [],
+        "depths": [20, 50, 100],
         "depth_unit": "mm",
         "cost": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
-        "u_value": None
+        "cost_unit": None,
+        "r_value_per_mm": 0.043478260869565216,
+        "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": 0.023,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
+
     },
     {
         "type": "external_wall_insulation",
-        "description": "Polyisocyanurate Foam External Wall Insulation",
+        "description": "Polyisocyanurate/Polyurethane Foam External Wall Insulation",
         "depths": [],
         "depth_unit": "mm",
         "cost": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
-        "u_value": None
+        "cost_unit": None,
+        "r_value_per_mm": None,
+        "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": None,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
     },
     {
+        # Example product
+        # https://www.mikewye.co.uk/product/steico-duo-dry/
         "type": "external_wall_insulation",
-        "description": "Woof Fiber External Wall Insulation",
-        "depths": [],
+        "description": "Wood Fiber External Wall Insulation",
+        "depths": [40, 60],
         "depth_unit": "mm",
         "cost": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
-        "u_value": None
+        "cost_unit": None,
+        "r_value_per_mm": 0.023255813953488375,
+        "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": 0.043,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
     },
     {
+        # Example product
+        # https://www.thermablok.co.uk/site/wp-content/uploads/2022/09/Thermablok-Aerogel-Insulation-Blanket-TDS-AIS
+        # -and-Steel-Related-Details.pdf
         "type": "external_wall_insulation",
         "description": "Aerogel External Wall Insulation",
-        "depths": [],
+        "depths": [10, 20, 30, 40, 50, 60, 70],
         "depth_unit": "mm",
         "cost": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
-        "u_value": None
+        "cost_unit": None,
+        "r_value_per_mm": 0.06666666666666667,
+        "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": 0.015,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
     },
     {
         "type": "external_wall_insulation",
         "description": "Vacuum Insulation Panels External Wall Insulation",
-        "depths": [],
+        "depths": [45, 60],
         "depth_unit": "mm",
         "cost": None,
-        # The u-value here is just a placehoder for now and we probably want to have multiple
-        # options for internal wall insulation (e.g. 50mm, 100mm, 150mm), with different material types
-        # and costs
-        "u_value": None
+        "cost_unit": None,
+        "r_value_per_mm": 0.16666666666666666,
+        "r_value_unit": "square_meter_kelvin_per_watt",
+        "thermal_conductivity": 0.006,
+        "thermal_conductivity_unit": "watt_per_meter_kelvin"
     }
 ]
 
@@ -270,3 +285,25 @@ class WallRecommendations:
             U-value in W/m²K.
         """
         return 1 / (depth_mm * r_value_per_mm)
+
+    @staticmethod
+    def thermal_conductivity_to_r_value_per_mm(thermal_conductivity: float) -> float:
+        """Convert thermal conductivity to R-value per mm.
+
+        Parameters
+        ----------
+        thermal_conductivity : float
+            Thermal conductivity (in W/mK).
+
+        Returns
+        -------
+        float
+            R-value per mm.
+        """
+        # Calculate R-value in m²K/W for 1 meter of the material
+        r_value_per_meter = 1 / thermal_conductivity
+
+        # Convert R-value to R-value per mm
+        r_value_per_mm = r_value_per_meter / 1000
+
+        return r_value_per_mm