diff --git a/backend/Property.py b/backend/Property.py
index 1cebc4a9..259ca724 100644
--- a/backend/Property.py
+++ b/backend/Property.py
@@ -350,6 +350,10 @@ class Property(Definitions):
 
         self.age_band = england_wales_age_band_lookup.get(self.construction_age_band)
 
+        if (self.data["transaction-type"] == "new dwelling") and (self.age_band is None):
+            self.age_band = "L"
+            self.construction_age_band = 'England and Wales: 2012 onwards'
+
         if self.age_band is None:
             raise ValueError("age_band is missing")