diff --git a/asset_list/AssetList.py b/asset_list/AssetList.py
index 2b80287c..c2784eb1 100644
--- a/asset_list/AssetList.py
+++ b/asset_list/AssetList.py
@@ -378,7 +378,7 @@ class AssetList:
         self.keep_variables = []
 
         # Finally, we handle the case where the landlord's property ID is actually the OS UPRN
-        if self.landlord_uprn == self.landlord_property_id:
+        if (self.landlord_uprn == self.landlord_property_id) and (self.landlord_property_id is not None):
             self.standardised_asset_list[self.STANDARD_UPRN] = self.standardised_asset_list[self.landlord_uprn].copy()
             # Update the reference to landlord UPRn
             self.landlord_uprn = self.STANDARD_UPRN
diff --git a/asset_list/app.py b/asset_list/app.py
index f164e94e..89b15c06 100644
--- a/asset_list/app.py
+++ b/asset_list/app.py
@@ -240,39 +240,43 @@ def app():
     # - We want: fully insulated property (all wall types), EPC D or below (floors should be solid)
     # - Or the insulation required is loft/cavity (floors should be solid)
 
-    DATA_FOLDER = "/Users/khalimconn-kowlessar/Documents/hestia/Customers/Colchester"
-    DATA_FILENAME = "Warmfront data- Colchester Borough Homes (Complete).xlsx"
-    SHEET_NAME = "Sheet1"
-    POSTCODE_COLUMN = 'Full Address.1'
-    FULLADDRESS_COLUMN = "Full Address"
-    ADDRESS1_COLUMN = None
-    ADDRESS1_METHOD = "first_word"
-    ADDRESS_COLS_TO_CONCAT = []
-    MISSING_POSTCODES_METHOD = None
-    PROPERTY_YEAR_BUILT = "Build Date"
-    UPRN_COLUMN = None
-    PROPERTY_TYPE_COLUMN = None
+    data_folder = "/Users/khalimconn-kowlessar/Documents/hestia/Customers/Colchester"
+    data_filename = "Warmfront data- Colchester Borough Homes (Complete).xlsx"
+    sheet_name = "Sheet1"
+    postcode_column = 'Full Address.1'
+    fulladdress_column = "Full Address"
+    address1_column = None
+    address1_method = "first_word"
+    address_cols_to_concat = []
+    missing_postcodes_method = None
+    landlord_year_built = "Build Date"
+    landlord_os_uprn = None
+    landlord_property_type = "Property Type"
+    landlord_wall_construction = "Wallinsul"
+    landlord_heating_system = "HeatSorc"
+    landlord_existing_pv = None
+    landlord_property_id = None
 
     # Maps addresses to uprn in problematic cases
     MANUAL_UPRN_MAP = {}
 
     asset_list = AssetList(
-        local_filepath=os.path.join(DATA_FOLDER, DATA_FILENAME),
+        local_filepath=os.path.join(data_folder, data_filename),
         header=0,
-        sheet_name=SHEET_NAME,
-        address1_colname=ADDRESS1_COLUMN,
-        postcode_colname=POSTCODE_COLUMN,
-        landlord_property_id="UPRN",
-        full_address_colname=FULLADDRESS_COLUMN,
-        full_address_cols_to_concat=ADDRESS_COLS_TO_CONCAT,
-        missing_postcodes_method=MISSING_POSTCODES_METHOD,
-        address1_extraction_method=ADDRESS1_METHOD,
-        landlord_year_built=PROPERTY_YEAR_BUILT,
-        landlord_uprn=UPRN_COLUMN,
-        landlord_property_type=PROPERTY_TYPE_COLUMN,
-        landlord_wall_construction="Wall Construction (EPC)",
-        landlord_heating_system="Heat Source",
-        landlord_existing_pv="PV (Y/N)"
+        sheet_name=sheet_name,
+        address1_colname=address1_column,
+        postcode_colname=postcode_column,
+        landlord_property_id=landlord_property_id,
+        full_address_colname=fulladdress_column,
+        full_address_cols_to_concat=address_cols_to_concat,
+        missing_postcodes_method=missing_postcodes_method,
+        address1_extraction_method=address1_method,
+        landlord_year_built=landlord_year_built,
+        landlord_uprn=landlord_os_uprn,
+        landlord_property_type=landlord_property_type,
+        landlord_wall_construction=landlord_wall_construction,
+        landlord_heating_system=landlord_heating_system,
+        landlord_existing_pv=landlord_existing_pv
     )
     asset_list.init_standardise()