diff --git a/archetypal/idfclass/end_use_balance.py b/archetypal/idfclass/end_use_balance.py
index 807144e1..6a38c107 100644
--- a/archetypal/idfclass/end_use_balance.py
+++ b/archetypal/idfclass/end_use_balance.py
@@ -564,8 +564,8 @@ def subtract_cooled_from_heated_surface(
             columns = None
         return EnergyDataFrame(
             (
-                _hvac_input_heated_surface.sum(level="Key_Name", axis=1)
-                - _hvac_input_cooled_surface.sum(level="Key_Name", axis=1)
+                _hvac_input_heated_surface.sum(level="KeyValue", axis=1)
+                - _hvac_input_cooled_surface.sum(level="KeyValue", axis=1)
             ).values,
             columns=columns,
             index=_hvac_input_heated_surface.index,