diff --git a/insel/templates/monthly_energy_balance.py b/insel/templates/monthly_energy_balance.py
index 76c175e..4c027bb 100644
--- a/insel/templates/monthly_energy_balance.py
+++ b/insel/templates/monthly_energy_balance.py
@@ -5,7 +5,7 @@ import pandas as pd
 import csv
 
 from imports.weather.helpers.weather import Weather as wt
-
+import helpers.constants as cte
 
 class MonthlyEnergyBalance:
   @staticmethod
@@ -90,8 +90,8 @@ class MonthlyEnergyBalance:
         window_area = 0
         for hole_polygon in thermal_boundary.surface.holes_polygons:
           window_area += hole_polygon.area
-      string = type_code + ' ' + str(0.85*thermal_boundary.area_above_ground) + ' ' + \
-          str(thermal_boundary.area_below_ground) + ' ' + str(thermal_boundary.u_value) + ' ' + \
+      string = type_code + ' ' + str(0.85*thermal_boundary.surface.area_above_ground) + ' ' + \
+          str(thermal_boundary.surface.area_below_ground) + ' ' + str(thermal_boundary.u_value) + ' ' + \
           str(0.85*window_area) + ' '
 
       if window_area <= 0.001:
@@ -109,7 +109,7 @@ class MonthlyEnergyBalance:
     file += '\r\n'
     file += 's 20 polyg 1\r\n'
     file += 'p 20 12 % Monthly ambient temperature\r\n'
-    external_temperature = building.external_temperature['month']
+    external_temperature = building.external_temperature[cte.MONTH]
     for i in range(0, len(external_temperature)):
       file += str(i+1) + ' ' + str(external_temperature.at[i, key]) + '\r\n'
 
@@ -131,7 +131,7 @@ class MonthlyEnergyBalance:
               ', inclination ' + str(np.rad2deg(surface.inclination)) + ' degrees\r\n'
 
       if surface.type != 'Ground':
-        global_irradiance = surface.global_irradiance['month']
+        global_irradiance = surface.global_irradiance[cte.MONTH]
         for j in range(0, len(global_irradiance)):
           file += str(j + 1) + ' ' + str(global_irradiance.at[j, 'sra']) + '\r\n'
       else:
diff --git a/main.py b/main.py
index 0b15b13..19c9d57 100644
--- a/main.py
+++ b/main.py
@@ -11,6 +11,7 @@ import ast
 import pandas as pd
 import datetime
 
+import helpers.constants as cte
 from helpers import monthly_values as mv
 from simplified_radiosity_algorithm import SimplifiedRadiosityAlgorithm
 from imports.geometry_factory import GeometryFactory
@@ -83,13 +84,13 @@ if not weather_step_in_pickle:
   city.climate_file = (path / f'{args.climate_reference_city}.cli').resolve()
   WeatherFactory(weather_format, populated_city, file_name=args.weather_file_name).enrich()
   for building in populated_city.buildings:
-    if 'hour' not in building.external_temperature:
+    if cte.HOUR not in building.external_temperature:
       print('No external temperature found')
       sys.exit()
 
-    if 'month' not in building.external_temperature:
-      building.external_temperature['month'] = mv.MonthlyValues().\
-        get_mean_values(building.external_temperature['hour'][[weather_format]])
+    if cte.MONTH not in building.external_temperature:
+      building.external_temperature[cte.MONTH] = mv.MonthlyValues().\
+        get_mean_values(building.external_temperature[cte.HOUR][[weather_format]])
 
   max_buildings_handled_by_sra = 500
   for building in city.buildings:
@@ -117,8 +118,6 @@ if not weather_step_in_pickle:
 print('begin_user_assignment_time', datetime.datetime.now())
 # Step 4: Assign user defined parameters
 for building in populated_city.buildings:
-  building.heated = True
-  building.cooled = False
   building.attic_heated = 2
   building.basement_heated = 0
 
@@ -127,12 +126,12 @@ print('begin_insel_time', datetime.datetime.now())
 MonthlyDemandCalculation(city, args.project_folder, weather_format).monthly_demand()
 
 print('begin_write_results_time', datetime.datetime.now())
-# Step 5: Print results
+# Step 6: Print results
 print_results = None
 file = 'city name: ' + city.name + '\n'
 for building in populated_city.buildings:
   insel_file_name = building.name + '.insel'
-  building_results = building.heating['month'].rename(columns={'INSEL': building.name})
+  building_results = building.heating[cte.MONTH].rename(columns={'INSEL': building.name})
   if print_results is None:
     print_results = building_results
   else: