diff --git a/backend/onboarders/epc_descriptions.py b/backend/onboarders/epc_descriptions.py
index 37f70df8..a4f0be13 100644
--- a/backend/onboarders/epc_descriptions.py
+++ b/backend/onboarders/epc_descriptions.py
@@ -108,6 +108,8 @@ class EpcWallDescriptions(Enum):
 
 class EpcRoofDescriptions(Enum):
     # Loft
+    # Assumed options
+    pitched_insulated_assumed = "Pitched, insulated (assumed)"
     # Known insulation at joists - we have 12, 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 270, 300, 350,
     # 400+ as options
     loft_12mm_insulation: str = "Pitched, 12 mm loft insulation"
diff --git a/backend/onboarders/parity.py b/backend/onboarders/parity.py
index a215d444..988ee01e 100644
--- a/backend/onboarders/parity.py
+++ b/backend/onboarders/parity.py
@@ -1,3 +1,4 @@
+from numpy import nan
 from tqdm import tqdm
 import pandas as pd
 from backend.onboarders.mappings.property_type import parity_map as property_map
@@ -290,23 +291,9 @@ roof_aggs = data[["Roof Construction", "Roof Insulation"]].drop_duplicates().to_
 
     # Pitched, loft
 
-    {'Roof Construction': 'PitchedNormalLoftAccess', 'Roof Insulation': nan},
-    {'Roof Construction': 'PitchedNormalLoftAccess', 'Roof Insulation': 'AsBuilt'},
-    {'Roof Construction': 'PitchedNormalLoftAccess', 'Roof Insulation': 'Unknown'},
-
     # Flat
-    {'Roof Construction': 'Flat', 'Roof Insulation': 'AsBuilt'},
-    {'Roof Construction': 'Flat', 'Roof Insulation': 'mm100'},
-    {'Roof Construction': 'Flat', 'Roof Insulation': 'mm150'},
-    {'Roof Construction': 'Flat', 'Roof Insulation': nan},
-
-    {'Roof Construction': 'Flat', 'Roof Insulation': 'Unknown'},
 
     # Thatched
-    {'Roof Construction': 'PitchedThatched', 'Roof Insulation': 'mm150'},
-    {'Roof Construction': 'PitchedThatched', 'Roof Insulation': 'Unknown'},
-    {'Roof Construction': 'PitchedThatched', 'Roof Insulation': 'mm50'},
-    {'Roof Construction': 'PitchedThatched', 'Roof Insulation': 'mm300'},
 
     # Sloping
     {'Roof Construction': 'PitchedWithSlopingCeiling', 'Roof Insulation': 'AsBuilt'},
@@ -317,10 +304,6 @@ roof_aggs = data[["Roof Construction", "Roof Insulation"]].drop_duplicates().to_
     {'Roof Construction': 'PitchedWithSlopingCeiling', 'Roof Insulation': 'NoInsulation'},
     {'Roof Construction': 'PitchedWithSlopingCeiling', 'Roof Insulation': 'Unknown'},
 
-    # Pitched no loft access
-    {'Roof Construction': 'PitchedNormalNoLoftAccess', 'Roof Insulation': nan},
-    {'Roof Construction': 'PitchedNormalNoLoftAccess', 'Roof Insulation': 'Unknown'},
-    {'Roof Construction': 'PitchedNormalNoLoftAccess', 'Roof Insulation': 'AsBuilt'}
 ]
 
 roof_mapping = {
@@ -353,6 +336,16 @@ roof_mapping = {
     ('PitchedNormalNoLoftAccess', 'mm350'): EpcRoofDescriptions.loft_350mm_insulation,
     ('PitchedNormalNoLoftAccess', 'mm400'): EpcRoofDescriptions.loft_400mm_plus_insulation,
 
+    # All pitched options with asbuilt or unknown got to EpcRoofDescriptions.pitched_insulated_assumed
+    # With access
+    ('PitchedNormalLoftAccess', nan): EpcRoofDescriptions.pitched_insulated_assumed,
+    ('PitchedNormalLoftAccess', 'AsBuilt'): EpcRoofDescriptions.pitched_insulated_assumed,
+    ('PitchedNormalLoftAccess', 'Unknown'): EpcRoofDescriptions.pitched_insulated_assumed,
+    # No access
+    ('PitchedNormalNoLoftAccess', nan): EpcRoofDescriptions.pitched_insulated_assumed,
+    ('PitchedNormalNoLoftAccess', 'AsBuilt'): EpcRoofDescriptions.pitched_insulated_assumed,
+    ('PitchedNormalNoLoftAccess', 'Unknown'): EpcRoofDescriptions.pitched_insulated_assumed,
+
     # Flat
     ('Flat', 'NoInsulation'): EpcRoofDescriptions.flat_no_insulation,
     # Flat - limited insulation
@@ -368,6 +361,10 @@ roof_mapping = {
     ('Flat', 'mm300'): EpcRoofDescriptions.flat_insulated,
     ('Flat', 'mm350'): EpcRoofDescriptions.flat_insulated,
     ('Flat', 'mm400'): EpcRoofDescriptions.flat_insulated,
+    # Flat - as built or unknown
+    ('Flat', 'AsBuilt'): None,  # To be classified
+    ('Flat', nan): None,  # To be classified
+    ('Flat', 'Unknown'): None,  # To be classified
 
     # 12mm = very poor & has limited insulation description
     # 25, 50 = poor & has limited insulation description
@@ -375,7 +372,11 @@ roof_mapping = {
     # 150, 175, 200, 225, 250mm = good (Flat, insulated)
     # 270mm+ = very good (Flat, insulated)
 
-    # {'Roof Construction': 'Flat', 'Roof Insulation': 'mm50'},
+    # Thatched
+    ('PitchedThatched', 'mm50'): EpcRoofDescriptions.thatched_with_additional_insulation,
+    ('PitchedThatched', 'mm150'): EpcRoofDescriptions.thatched_with_additional_insulation,
+    ('PitchedThatched', 'mm300'): EpcRoofDescriptions.thatched_with_additional_insulation,
+    ('PitchedThatched', 'Unknown'): EpcRoofDescriptions.thatched,  # efficiency classified based on age
 
 }
 
@@ -403,10 +404,6 @@ def classify_flat_roof(age_band: EpcConstructionAgeBand) -> EpcRoofDescriptions:
     return EpcRoofDescriptions.flat_no_insulation
 
 
-def classify_pitched_loft_unknown(age_band: EpcConstructionAgeBand):
-    raise NotImplementedError("Pitched loft (unknown insulation) not implemented yet")
-
-
 def classify_thatched_roof(age_band: EpcConstructionAgeBand):
     raise NotImplementedError("Thatched roof classification not implemented yet")
 
@@ -417,8 +414,6 @@ def classify_sloping_ceiling_roof(age_band: EpcConstructionAgeBand):
 
 AS_BUILT_ROOF_CLASSIFIERS = {
     "Flat": classify_flat_roof,
-    "PitchedNormalLoftAccess": classify_pitched_loft_unknown,
-    "PitchedNormalNoLoftAccess": classify_pitched_loft_unknown,
     "PitchedThatched": classify_thatched_roof,
     "PitchedWithSlopingCeiling": classify_sloping_ceiling_roof,
 }