diff --git a/results.py b/results.py
index c00c167..bd4beb2 100644
--- a/results.py
+++ b/results.py
@@ -11,22 +11,30 @@ class Results:
   def print(self):
     print_results = None
     file = 'city name: ' + self._city.name + '\n'
+    array = [None] * 12
     for building in self._city.buildings:
       if cte.MONTH in building.heating.keys():
         heating_results = building.heating[cte.MONTH].rename(columns={cte.INSEL_MEB: f'{building.name} heating Wh'})
+      else:
+        heating_results = pd.DataFrame(array, columns=[f'{building.name} heating Wh'])
+      if cte.MONTH in building.cooling.keys():
         cooling_results = building.cooling[cte.MONTH].rename(columns={cte.INSEL_MEB: f'{building.name} cooling Wh'})
+      else:
+        cooling_results = pd.DataFrame(array, columns=[f'{building.name} cooling Wh'])
+      if cte.MONTH in building.lighting_electrical_demand.keys():
         lighting_results = building.lighting_electrical_demand[cte.MONTH]\
           .rename(columns={cte.INSEL_MEB: f'{building.name} lighting electrical demand Wh'})
-        appliances_results = building.appliances_electrical_demand[cte.MONTH]\
+      else:
+        lighting_results = pd.DataFrame(array, columns=[f'{building.name} lighting electrical demand Wh'])
+      if cte.MONTH in building.appliances_electrical_demand.keys():
+          appliances_results = building.appliances_electrical_demand[cte.MONTH]\
           .rename(columns={cte.INSEL_MEB: f'{building.name} appliances electrical demand Wh'})
+      else:
+        appliances_results = pd.DataFrame(array, columns=[f'{building.name} appliances electrical demand Wh'])
+      if cte.MONTH in building.domestic_hot_water_heat_demand.keys():
         dhw_results = building.domestic_hot_water_heat_demand[cte.MONTH]\
           .rename(columns={cte.INSEL_MEB: f'{building.name} domestic hot water demand Wh'})
       else:
-        array = [None] * 12
-        heating_results = pd.DataFrame(array, columns=[f'{building.name} heating Wh'])
-        cooling_results = pd.DataFrame(array, columns=[f'{building.name} cooling Wh'])
-        lighting_results = pd.DataFrame(array, columns=[f'{building.name} lighting electrical demand Wh'])
-        appliances_results = pd.DataFrame(array, columns=[f'{building.name} appliances electrical demand Wh'])
         dhw_results = pd.DataFrame(array, columns=[f'{building.name} domestic hot water demand Wh'])
       if print_results is None:
         print_results = heating_results