diff --git a/model_data/app.py b/model_data/app.py
index 9f84c396..e6caa5cf 100644
--- a/model_data/app.py
+++ b/model_data/app.py
@@ -104,11 +104,8 @@ def handler():
         [{"address1": p.address1, **p.walls} for p in input_properties]
     )
 
-    # Key values
-    # This is based on the standards set out by part L of the building regulations
-    WALLS_MAX_U_VALUE = 0.18
-
     input_properties[1].data["address1"]
+    input_properties[1].data["postcode"]
     walls_df["address1"].values[1]
     walls_df["original_description"].values[1]
     # Walls
@@ -121,6 +118,10 @@ def handler():
     # if building built after 1990 + we're able to identify U-value + U-value less than 0.18
     # and if in or close to a conversation area, recommend internal wall insulation
     # Property 1
+    # 'Flat 14 Godley V C House', Solid brick, as built, no insulation (assumed)
+    # Since the wall is solid brick (therefore no cavity), we can recommend the following:
+    # External wall insulation
+    # Internal wall insulation
 
     from model_data.recommendations.WallRecommendations import WallRecommendations
     self = WallRecommendations(property_instance=input_properties[0])
diff --git a/model_data/recommendations/WallRecommendations.py b/model_data/recommendations/WallRecommendations.py
index 2b754d65..08b2c16f 100644
--- a/model_data/recommendations/WallRecommendations.py
+++ b/model_data/recommendations/WallRecommendations.py
@@ -1,13 +1,98 @@
-import math
+import pint
 
 from model_data.Property import Property
 import pandas as pd
 
+external_wall_insulation_parts = [
+    {
+        # Example product
+        # https://insulationgo.co.uk/100mm-rockwool-external-wall-insulation-dual-density-slabs-a1-non-combustible
+        # -slab-ewi-render-fire/
+        "type": "external_wall_insulation",
+        "description": "Mineral Wool 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
+    },
+    {
+        "type": "external_wall_insulation",
+        "description": "Expanded Polystyrene 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
+    },
+    {
+        "type": "external_wall_insulation",
+        "description": "Phenolic 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
+    },
+    {
+        "type": "external_wall_insulation",
+        "description": "Polyisocyanurate 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
+    },
+    {
+        "type": "external_wall_insulation",
+        "description": "Woof Fiber 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
+    },
+    {
+        "type": "external_wall_insulation",
+        "description": "Aerogel 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
+    },
+    {
+        "type": "external_wall_insulation",
+        "description": "Vacuum Insulation Panels 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
+    }
+]
+
 wall_parts = [
     {
         "id": 1,
         "type": "internal_wall_insulation",
         "description": "Internal wall insulation",
+        "depth": None,
+        "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
@@ -27,6 +112,10 @@ class WallRecommendations:
     # we still consider it as an option
     U_VALUE_ERROR = 0.01
 
+    DEFAULT_U_VALUES = {
+        "solid_brick": 2,
+    }
+
     def __init__(self, property_instance: Property):
         self.property = property_instance
         self.year_built = self._year_property_was_built()
@@ -67,11 +156,14 @@ class WallRecommendations:
                     _, new_u_value = self.calculate_u_value_uplift(u_value, part["u_value"])
                     new_u_value = round(new_u_value, 2)
 
-                    self.recommendations.append(
-                        {
-                            **part, "new_u_value": new_u_value,
-                        }
-                    )
+                    # We allow a small tolerance for error so we don't discount the recommendation entirely
+                    # if it's close, since this is an estimated new u-value
+                    if new_u_value - self.U_VALUE_ERROR <= self.BUILDING_REGULATIONS_PART_L_MAX_U_VALUE:
+                        self.recommendations.append(
+                            {
+                                **part, "new_u_value": new_u_value,
+                            }
+                        )
 
         raise NotImplementedError("Not implemented yet")
 
@@ -104,3 +196,25 @@ class WallRecommendations:
         u_value_uplift = u_value - new_u_value
 
         return u_value_uplift, new_u_value
+
+    @staticmethod
+    def convert_r_value_to_mm(r_value_wmk):
+        """
+        Converts an R-value from units of W/m·K to per millimeter (mm).
+
+        :param r_value_wmk: R-value in units of W/m·K.
+        :type r_value_wmk: float
+
+        :return: Converted R-value per mm.
+        :rtype: float
+
+        :notes:
+            - This function utilizes the 'pint' library to handle units and perform the conversion.
+        """
+
+        ureg = pint.UnitRegistry()
+
+        r_value = r_value_wmk * ureg.watt / (ureg.meter * ureg.kelvin)
+        r_value_per_mm = r_value.to(1 / ureg.millimeter)
+
+        return r_value_per_mm.magnitude
diff --git a/model_data/requirements.txt b/model_data/requirements.txt
index a21cdf6e..0b3cd265 100644
--- a/model_data/requirements.txt
+++ b/model_data/requirements.txt
@@ -10,4 +10,5 @@ pytest-mock
 fuzzywuzzy
 python-Levenshtein
 dbfread
-pyproj
\ No newline at end of file
+pyproj
+pint
\ No newline at end of file