diff --git a/backend/app/db/models/materials.py b/backend/app/db/models/materials.py
index 347b66d5..9b38addd 100644
--- a/backend/app/db/models/materials.py
+++ b/backend/app/db/models/materials.py
@@ -19,6 +19,7 @@ class MaterialType(enum.Enum):
     flat_roof_insulation = "flat_roof_insulation"
     room_roof_insulation = "room_roof_insulation"
     windows_glazing = "windows_glazing"
+    secondary_glazing = "secondary_glazing"
     cavity_wall_extraction = "cavity_wall_extraction"
 
     iwi_wall_demolition = "iwi_wall_demolition"