diff --git a/loads_calculation.py b/loads_calculation.py
index e6a0867..8b29d94 100644
--- a/loads_calculation.py
+++ b/loads_calculation.py
@@ -6,10 +6,7 @@ Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
 
 
-import helpers.constants as cte
-
-AIR_DENSITY = 1.293  # kg/m3
-AIR_HEAT_CAPACITY = 1005.2  # J/kgK
+import hub.helpers.constants as cte
 
 
 class LoadsCalculation:
@@ -44,12 +41,12 @@ class LoadsCalculation:
   @staticmethod
   def _get_load_ventilation(thermal_zone, internal_temperature, ambient_temperature):
     load_renovation_sensible = 0
-    for usage in thermal_zone.usage_zones:
-      load_renovation_sensible += AIR_DENSITY * AIR_HEAT_CAPACITY * usage.mechanical_air_change \
+    for usage in thermal_zone.usages:
+      load_renovation_sensible += cte.AIR_DENSITY * cte.AIR_HEAT_CAPACITY * usage.mechanical_air_change \
                                 * thermal_zone.volume / cte.HOUR_TO_MINUTES / cte.MINUTES_TO_SECONDS \
                                 * (internal_temperature - ambient_temperature)
 
-    load_infiltration_sensible = AIR_DENSITY * AIR_HEAT_CAPACITY * float(thermal_zone.infiltration_rate_system_off) \
+    load_infiltration_sensible = cte.AIR_DENSITY * cte.AIR_HEAT_CAPACITY * thermal_zone.infiltration_rate_system_off \
                                  * thermal_zone.volume / cte.HOUR_TO_MINUTES / cte.MINUTES_TO_SECONDS \
                                  * (internal_temperature - ambient_temperature)
 
diff --git a/peak_loads.py b/peak_loads.py
index 9fbbca6..f0f823f 100644
--- a/peak_loads.py
+++ b/peak_loads.py
@@ -7,7 +7,7 @@ Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 
 from pathlib import Path
 
-import helpers.constants as cte
+import hub.helpers.constants as cte
 from loads_calculation import LoadsCalculation
 
 
@@ -47,13 +47,12 @@ class PeakLoads:
   def _workflow(self):
     for building in self._city.buildings:
       ambient_temperature = building.external_temperature[cte.HOUR][self._weather_format]
-      ground_temperature = 0
+      ground_temperature = building.ground_temperature[cte.YEAR]['2'][0]
       heating_ambient_temperature = 100
       cooling_ambient_temperature = -100
       heating_calculation_hour = -1
       cooling_calculation_hour = -1
       for hour, temperature in enumerate(ambient_temperature):
-        ground_temperature += temperature / 8760
         if temperature < heating_ambient_temperature:
           heating_ambient_temperature = temperature
           heating_calculation_hour = hour
diff --git a/unittests/test_peak_loads_workflow.py b/unittests/test_peak_loads_workflow.py
index 878ce2f..515d02f 100644
--- a/unittests/test_peak_loads_workflow.py
+++ b/unittests/test_peak_loads_workflow.py
@@ -8,12 +8,12 @@ Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 from pathlib import Path
 from unittest import TestCase
 import pandas as pd
-import helpers.constants as cte
+import hub.helpers.constants as cte
 from helpers.monthly_values import MonthlyValues
-from imports.geometry_factory import GeometryFactory
-from imports.construction_factory import ConstructionFactory
-from imports.usage_factory import UsageFactory
-from imports.weather_factory import WeatherFactory
+from hub.imports.geometry_factory import GeometryFactory
+from hub.imports.construction_factory import ConstructionFactory
+from hub.imports.usage_factory import UsageFactory
+from hub.imports.weather_factory import WeatherFactory
 from peak_loads import PeakLoads
 
 
@@ -96,7 +96,7 @@ class TestPeakLoadsWorkflow(TestCase):
     weather_file = 'CAN_PQ_Montreal.Intl.AP.716270_CWEC.epw'
     weather_format = 'epw'
     irradiance_format = 'sra'
-    construction_format = 'nrel'
-    usage_format = 'comnet'
+    construction_format = 'nrcan'
+    usage_format = 'nrcan'
     self._enrich_city(city, weather_file, weather_format, irradiance_format, construction_format, usage_format)
     PeakLoads(city, outputs_path, weather_format, irradiance_format)