diff --git a/domain/magicplan/mapper.py b/domain/magicplan/mapper.py
index 2aa03421c..6d7d5f422 100644
--- a/domain/magicplan/mapper.py
+++ b/domain/magicplan/mapper.py
@@ -99,8 +99,16 @@ def _map_window_ventilation(
         opening_type=_try_get_str_value("Opening Type"),
         num_openings=_try_get_int_value("Number of Openings (In Same Window)"),
         pct_openable=_try_get_int_value("% of Window Openable"),
-        trickle_vent_area_mm2=_try_get_int_value(
-            "Total Trickle Vent Effective Area (mm2) (No Code Then Width x Height)"
+        trickle_vent_area_mm2=next(
+            (
+                v
+                for label in [
+                    "Total Trickle Vent Effective Area (mm2) (No Code Then Width x Height)",
+                    "Trickle Vent Effective Area (mm2) (No Code Then Width x Height)",
+                ]
+                if (v := _try_get_int_value(label)) is not None
+            ),
+            None,
         ),
         num_trickle_vents=_try_get_int_value("No. of Trickle Vents"),
     )