diff --git a/insel/templates/monthly_energy_balance.py b/insel/templates/monthly_energy_balance.py
index 04cf3ac..59c274f 100644
--- a/insel/templates/monthly_energy_balance.py
+++ b/insel/templates/monthly_energy_balance.py
@@ -41,7 +41,7 @@ class MonthlyEnergyBalance:
               str(i + 1) + ' (sqm)' + '\r\n'
       total_internal_gains = 0
       for ig in usage_zone.internal_gains:
-        total_internal_gains += float(ig.average_internal_gain_w_m2) * \
+        total_internal_gains += float(ig.average_internal_gain) * \
                                 (float(ig.convective_fraction) + float(ig.radiative_fraction))
       file += str(total_internal_gains) + '  % BP(12) #2 Internal gains of zone ' + str(i + 1) + '\r\n'
       file += str(usage_zone.heating_setpoint) + '  % BP(13) #3 Heating setpoint temperature zone ' + \