diff --git a/city_model_structure/attributes/thermal_zone.py b/city_model_structure/attributes/thermal_zone.py
index 633b03a1..e5cd3441 100644
--- a/city_model_structure/attributes/thermal_zone.py
+++ b/city_model_structure/attributes/thermal_zone.py
@@ -207,7 +207,7 @@ class ThermalZone:
   @property
   def usage_zones(self) -> List[UsageZone]:
     """
-    Get thermal zone usages zones
+    Get thermal zone usage zones
     :return: [UsageZone]
     """
     return self._usage_zones
@@ -215,7 +215,7 @@ class ThermalZone:
   @usage_zones.setter
   def usage_zones(self, values):
     """
-    Set thermal zone usages zones
+    Set thermal zone usage zones
     :param values: [UsageZone]
     :return: None
     """
diff --git a/city_model_structure/attributes/usage_zone.py b/city_model_structure/attributes/usage_zone.py
index 085b40bb..43761bf5 100644
--- a/city_model_structure/attributes/usage_zone.py
+++ b/city_model_structure/attributes/usage_zone.py
@@ -52,7 +52,7 @@ class UsageZone:
   @property
   def internal_gains(self) -> List[InternalGains]:
     """
-    Get usages zone internal gains
+    Get usage zone internal gains
     :return: [InternalGains]
     """
     return self._internal_gains
@@ -60,7 +60,7 @@ class UsageZone:
   @internal_gains.setter
   def internal_gains(self, value):
     """
-    Set usages zone internal gains
+    Set usage zone internal gains
     :param value: [InternalGains]
     :return: None
     """
@@ -69,7 +69,7 @@ class UsageZone:
   @property
   def heating_setpoint(self):
     """
-    Get usages zone heating set point in celsius grads
+    Get usage zone heating set point in celsius grads
     :return: float
     """
     return self._heating_setpoint
@@ -77,7 +77,7 @@ class UsageZone:
   @heating_setpoint.setter
   def heating_setpoint(self, value):
     """
-    Set usages zone heating set point in celsius grads
+    Set usage zone heating set point in celsius grads
     :param value: float
     :return: None
     """
@@ -86,7 +86,7 @@ class UsageZone:
   @property
   def heating_setback(self):
     """
-    Get usages zone heating setback in celsius grads
+    Get usage zone heating setback in celsius grads
     :return: float
     """
     return self._heating_setback
@@ -94,7 +94,7 @@ class UsageZone:
   @heating_setback.setter
   def heating_setback(self, value):
     """
-    Set usages zone heating setback in celsius grads
+    Set usage zone heating setback in celsius grads
     :param value: float
     :return: None
     """
@@ -103,7 +103,7 @@ class UsageZone:
   @property
   def cooling_setpoint(self):
     """
-    Get usages zone cooling setpoint in celsius grads
+    Get usage zone cooling setpoint in celsius grads
     :return: float
     """
     return self._cooling_setpoint
@@ -111,7 +111,7 @@ class UsageZone:
   @cooling_setpoint.setter
   def cooling_setpoint(self, value):
     """
-    Set usages zone cooling setpoint in celsius grads
+    Set usage zone cooling setpoint in celsius grads
     :param value: float
     :return: None
     """
@@ -120,7 +120,7 @@ class UsageZone:
   @property
   def hours_day(self):
     """
-    Get usages zone usages hours per day
+    Get usage zone usage hours per day
     :return: float
     """
     return self._hours_day
@@ -128,7 +128,7 @@ class UsageZone:
   @hours_day.setter
   def hours_day(self, value):
     """
-    Set usages zone usages hours per day
+    Set usage zone usage hours per day
     :param value: float
     :return: float
     """
@@ -137,7 +137,7 @@ class UsageZone:
   @property
   def days_year(self):
     """
-    Get usages zone usages days per year
+    Get usage zone usage days per year
     :return: float
     """
     return self._days_year
@@ -145,7 +145,7 @@ class UsageZone:
   @days_year.setter
   def days_year(self, value):
     """
-    Set usages zone usages days per year
+    Set usage zone usage days per year
     :param value: float
     :return: None
     """
@@ -154,7 +154,7 @@ class UsageZone:
   @property
   def mechanical_air_change(self):
     """
-    Set usages zone mechanical air change in air change per hour (ACH)
+    Set usage zone mechanical air change in air change per hour (ACH)
     :return: float
     """
     return self._mechanical_air_change
@@ -162,7 +162,7 @@ class UsageZone:
   @mechanical_air_change.setter
   def mechanical_air_change(self, value):
     """
-    Get usages zone mechanical air change in air change per hour (ACH)
+    Get usage zone mechanical air change in air change per hour (ACH)
     :param value: float
     :return: None
     """
@@ -171,7 +171,7 @@ class UsageZone:
   @property
   def usage(self):
     """
-    Get usages zone usages
+    Get usage zone usage
     :return: str
     """
     return self._usage
@@ -179,7 +179,7 @@ class UsageZone:
   @usage.setter
   def usage(self, value):
     """
-    Get usages zone usages
+    Get usage zone usage
     :param value: str
     :return: None
     """
diff --git a/city_model_structure/building.py b/city_model_structure/building.py
index 6add7de4..2cd9483c 100644
--- a/city_model_structure/building.py
+++ b/city_model_structure/building.py
@@ -120,7 +120,7 @@ class Building(CityObject):
   @property
   def usage_zones(self) -> List[UsageZone]:
     """
-    Get city object usages zones
+    Get city object usage zones
     :return: [UsageZone]
     """
     return self._usage_zones
@@ -128,7 +128,7 @@ class Building(CityObject):
   @usage_zones.setter
   def usage_zones(self, values):
     """
-    Set city objects usages zones
+    Set city objects usage zones
     :param values: [UsageZones]
     :return: None
     """
diff --git a/city_model_structure/city.py b/city_model_structure/city.py
index 24f4376f..54d76deb 100644
--- a/city_model_structure/city.py
+++ b/city_model_structure/city.py
@@ -44,6 +44,7 @@ class City:
     self._buildings_clusters = None
     self._parts_consisting_buildings = None
     self._city_objects_clusters = None
+    self._city_objects = None
 
   def _get_location(self) -> Location:
     if self._location is None:
@@ -97,7 +98,15 @@ class City:
     City objects belonging to the city
     :return: None or [CityObject]
     """
-    return self.buildings
+    if self._city_objects is None:
+      if self.city_objects_clusters is None:
+        self._city_objects = []
+      else:
+        self._city_objects = self.city_objects_clusters
+      if self.buildings is not None:
+        for building in self.buildings:
+          self._city_objects.append(building)
+    return self._city_objects
 
   @property
   def buildings(self) -> Union[List[Building], None]:
@@ -171,7 +180,6 @@ class City:
     else:
       raise NotImplementedError(new_city_object.type)
 
-
   def remove_city_object(self, city_object):
     """
     Remove a CityObject from the city
@@ -313,6 +321,12 @@ class City:
     City objects clusters belonging to the city
     :return: None or [CityObjectsCluster]
     """
+    if self.buildings_clusters is None:
+      self._city_objects_clusters = []
+    else:
+      self._city_objects_clusters = self.buildings_clusters
+    if self.parts_consisting_buildings is not None:
+      self._city_objects_clusters.append(self.parts_consisting_buildings)
     return self._city_objects_clusters
 
   def add_city_objects_cluster(self, new_city_objects_cluster):
@@ -321,7 +335,6 @@ class City:
     :param new_city_objects_cluster:CityObjectsCluster
     :return: None
     """
-    print(new_city_objects_cluster.type)
     if new_city_objects_cluster.type == 'buildings':
       if self._buildings_clusters is None:
         self._buildings_clusters = []
diff --git a/city_model_structure/city_object.py b/city_model_structure/city_object.py
index 091cabfb..ace50dae 100644
--- a/city_model_structure/city_object.py
+++ b/city_model_structure/city_object.py
@@ -224,4 +224,4 @@ class CityObject:
     Sensor list belonging to the city object
     :param value: [Sensor]
     """
-    self._sensors = value
\ No newline at end of file
+    self._sensors = value
diff --git a/city_model_structure/city_objects_cluster.py b/city_model_structure/city_objects_cluster.py
index be5397b0..910c31da 100644
--- a/city_model_structure/city_objects_cluster.py
+++ b/city_model_structure/city_objects_cluster.py
@@ -5,9 +5,12 @@ Copyright © 2020 Project Author Pilar Monsalvete Alvarez de Uribarri pilar.mons
 """
 
 from abc import ABC
+from typing import List
+from city_model_structure.attributes.sensor import Sensor
+from city_model_structure.city_object import CityObject
 
 
-class CityObjectsCluster(ABC):
+class CityObjectsCluster(ABC, CityObject):
   """
   CityObjectsCluster(ABC) class
   """
@@ -15,6 +18,9 @@ class CityObjectsCluster(ABC):
     self._name = name
     self._cluster_type = cluster_type
     self._city_objects = city_objects
+    self._sensors = []
+    self._lod = ''
+    super(ABC, self).__init__(name, self._lod, None, None)
 
   @property
   def name(self):
@@ -34,3 +40,19 @@ class CityObjectsCluster(ABC):
     else:
       self._city_objects.append(city_object)
     return self._city_objects
+
+  @property
+  def sensors(self) -> List[Sensor]:
+    """
+    Sensor list belonging to the city objects cluster
+    :return: [Sensor]
+    """
+    return self._sensors
+
+  @sensors.setter
+  def sensors(self, value):
+    """
+    Sensor list belonging to the city objects cluster
+    :param value: [Sensor]
+    """
+    self._sensors = value
diff --git a/exports/formats/energy_ade.py b/exports/formats/energy_ade.py
index 2c54e32d..1c0f9bb8 100644
--- a/exports/formats/energy_ade.py
+++ b/exports/formats/energy_ade.py
@@ -166,7 +166,7 @@ class EnergyAde:
   def _building_geometry(self, building, building_dic, city):
 
     building_dic['bldg:Building']['bldg:function'] = building.function
-    building_dic['bldg:Building']['bldg:usages'] = ', '.join([u.usage for u in building.usage_zones])
+    building_dic['bldg:Building']['bldg:usage'] = ', '.join([u.usage for u in building.usage_zones])
     building_dic['bldg:Building']['bldg:yearOfConstruction'] = building.year_of_construction
     building_dic['bldg:Building']['bldg:roofType'] = building.roof_type
     building_dic['bldg:Building']['bldg:measuredHeight'] = {
diff --git a/exports/formats/idf.py b/exports/formats/idf.py
index fa3770e0..81b46ee8 100644
--- a/exports/formats/idf.py
+++ b/exports/formats/idf.py
@@ -116,7 +116,7 @@ class Idf:
   def _add_heating_system(self, building):
     for usage_zone in building.usage_zones:
       thermostat_name = f'Thermostat {building.name}'
-      # todo: this will fail for more than one usages zone
+      # todo: this will fail for more than one usage zone
       static_thermostat = self._idf.newidfobject(self._THERMOSTAT,
                                                  Name=thermostat_name,
                                                  Constant_Heating_Setpoint=usage_zone.heating_setpoint,
diff --git a/imports/constructions/ca_physics_parameters.py b/imports/construction/ca_physics_parameters.py
similarity index 95%
rename from imports/constructions/ca_physics_parameters.py
rename to imports/construction/ca_physics_parameters.py
index afe4015a..a64054ee 100644
--- a/imports/constructions/ca_physics_parameters.py
+++ b/imports/construction/ca_physics_parameters.py
@@ -5,8 +5,8 @@ Copyright © 2020 Project Author Pilar Monsalvete pilar_monsalvete@yahoo.es
 """
 import sys
 
-from imports.constructions.nrel_physics_interface import NrelPhysicsInterface
-from imports.constructions.helpers.construction_helper import ConstructionHelper
+from imports.construction.nrel_physics_interface import NrelPhysicsInterface
+from imports.construction.helpers.construction_helper import ConstructionHelper
 
 
 class CaPhysicsParameters(NrelPhysicsInterface):
diff --git a/imports/constructions/data_classes/nrel_building_achetype.py b/imports/construction/data_classes/nrel_building_achetype.py
similarity index 96%
rename from imports/constructions/data_classes/nrel_building_achetype.py
rename to imports/construction/data_classes/nrel_building_achetype.py
index 1e7fa855..afa25c6e 100644
--- a/imports/constructions/data_classes/nrel_building_achetype.py
+++ b/imports/construction/data_classes/nrel_building_achetype.py
@@ -4,7 +4,7 @@ SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Pilar Monsalvete pilar_monsalvete@yahoo.es
 """
 from typing import List
-from imports.constructions.data_classes.nrel_thermal_boundary_archetype import NrelThermalBoundaryArchetype
+from imports.construction.data_classes.nrel_thermal_boundary_archetype import NrelThermalBoundaryArchetype
 
 
 class NrelBuildingArchetype:
diff --git a/imports/constructions/data_classes/nrel_layer_archetype.py b/imports/construction/data_classes/nrel_layer_archetype.py
similarity index 100%
rename from imports/constructions/data_classes/nrel_layer_archetype.py
rename to imports/construction/data_classes/nrel_layer_archetype.py
diff --git a/imports/constructions/data_classes/nrel_thermal_boundary_archetype.py b/imports/construction/data_classes/nrel_thermal_boundary_archetype.py
similarity index 91%
rename from imports/constructions/data_classes/nrel_thermal_boundary_archetype.py
rename to imports/construction/data_classes/nrel_thermal_boundary_archetype.py
index c5452359..52d4b86e 100644
--- a/imports/constructions/data_classes/nrel_thermal_boundary_archetype.py
+++ b/imports/construction/data_classes/nrel_thermal_boundary_archetype.py
@@ -5,8 +5,8 @@ Copyright © 2020 Project Author Pilar Monsalvete pilar_monsalvete@yahoo.es
 """
 from typing import List
 
-from imports.constructions.data_classes.nrel_layer_archetype import NrelLayerArchetype
-from imports.constructions.data_classes.nrel_thermal_opening_archetype import NrelThermalOpeningArchetype
+from imports.construction.data_classes.nrel_layer_archetype import NrelLayerArchetype
+from imports.construction.data_classes.nrel_thermal_opening_archetype import NrelThermalOpeningArchetype
 
 
 class NrelThermalBoundaryArchetype:
diff --git a/imports/constructions/data_classes/nrel_thermal_opening_archetype.py b/imports/construction/data_classes/nrel_thermal_opening_archetype.py
similarity index 100%
rename from imports/constructions/data_classes/nrel_thermal_opening_archetype.py
rename to imports/construction/data_classes/nrel_thermal_opening_archetype.py
diff --git a/imports/constructions/helpers/construction_helper.py b/imports/construction/helpers/construction_helper.py
similarity index 100%
rename from imports/constructions/helpers/construction_helper.py
rename to imports/construction/helpers/construction_helper.py
diff --git a/imports/constructions/nrel_physics_interface.py b/imports/construction/nrel_physics_interface.py
similarity index 95%
rename from imports/constructions/nrel_physics_interface.py
rename to imports/construction/nrel_physics_interface.py
index 1003a8e1..1bd772eb 100644
--- a/imports/constructions/nrel_physics_interface.py
+++ b/imports/construction/nrel_physics_interface.py
@@ -6,10 +6,10 @@ Copyright © 2020 Project Author Pilar Monsalvete pilar_monsalvete@yahoo.es
 """
 import xmltodict
 
-from imports.constructions.data_classes.nrel_building_achetype import NrelBuildingArchetype as nba
-from imports.constructions.data_classes.nrel_thermal_boundary_archetype import NrelThermalBoundaryArchetype as ntba
-from imports.constructions.data_classes.nrel_thermal_opening_archetype import NrelThermalOpeningArchetype as ntoa
-from imports.constructions.data_classes.nrel_layer_archetype import NrelLayerArchetype as nla
+from imports.construction.data_classes.nrel_building_achetype import NrelBuildingArchetype as nba
+from imports.construction.data_classes.nrel_thermal_boundary_archetype import NrelThermalBoundaryArchetype as ntba
+from imports.construction.data_classes.nrel_thermal_opening_archetype import NrelThermalOpeningArchetype as ntoa
+from imports.construction.data_classes.nrel_layer_archetype import NrelLayerArchetype as nla
 
 
 class NrelPhysicsInterface:
@@ -59,7 +59,7 @@ class NrelPhysicsInterface:
         raise Exception(f'infiltration rate for ventilation when system on units = {units}, expected ACH')
 
       thermal_boundary_archetypes = []
-      for construction in archetype['constructions']['construction']:
+      for construction in archetype['construction']['construction']:
         construction_type = construction['@type']
         construction_id = construction['@id']
 
diff --git a/imports/constructions/us_physics_parameters.py b/imports/construction/us_physics_parameters.py
similarity index 97%
rename from imports/constructions/us_physics_parameters.py
rename to imports/construction/us_physics_parameters.py
index a924ece6..f5459c5f 100644
--- a/imports/constructions/us_physics_parameters.py
+++ b/imports/construction/us_physics_parameters.py
@@ -6,8 +6,8 @@ Contributors Pilar Monsalvete pilar_monsalvete@yahoo.es
 """
 import sys
 
-from imports.constructions.nrel_physics_interface import NrelPhysicsInterface
-from imports.constructions.helpers.construction_helper import ConstructionHelper
+from imports.construction.nrel_physics_interface import NrelPhysicsInterface
+from imports.construction.helpers.construction_helper import ConstructionHelper
 from city_model_structure.attributes.layer import Layer
 from city_model_structure.attributes.material import Material
 
diff --git a/imports/construction_factory.py b/imports/construction_factory.py
index 2634bee5..33b769a7 100644
--- a/imports/construction_factory.py
+++ b/imports/construction_factory.py
@@ -3,8 +3,8 @@ ConstructionFactory (before PhysicsFactory) retrieve the specific construction m
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Guille Gutierrez guillermo.gutierrezmorote@concordia.ca
 """
-from imports.constructions.us_physics_parameters import UsPhysicsParameters
-from imports.constructions.ca_physics_parameters import CaPhysicsParameters
+from imports.construction.us_physics_parameters import UsPhysicsParameters
+from imports.construction.ca_physics_parameters import CaPhysicsParameters
 from pathlib import Path
 
 
diff --git a/imports/geometry/helpers/geometry_helper.py b/imports/geometry/helpers/geometry_helper.py
index 42b0e6c0..f4d94faa 100644
--- a/imports/geometry/helpers/geometry_helper.py
+++ b/imports/geometry/helpers/geometry_helper.py
@@ -245,7 +245,7 @@ class GeometryHelper:
     'large office': 'large office'
   }
 
-  # usages
+  # usage
   fuction_to_usage = {
     'full service restaurant': 'restaurant',
     'highrise apartment': 'residential',
@@ -288,7 +288,7 @@ class GeometryHelper:
   @staticmethod
   def usage_from_function(building_function):
     """
-    Get the internal usages for the given internal building function
+    Get the internal usage for the given internal building function
     :param building_function: str
     :return: str
     """
diff --git a/imports/schedules/comnet_schedules_parameters.py b/imports/schedules/comnet_schedules_parameters.py
index 85eabd90..b4dbae41 100644
--- a/imports/schedules/comnet_schedules_parameters.py
+++ b/imports/schedules/comnet_schedules_parameters.py
@@ -1,5 +1,5 @@
 """
-Schedules retrieve the specific usages schedules module for the given standard
+Schedules retrieve the specific usage schedules module for the given standard
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Guille Gutierrez guillermo.gutierrezmorote@concordia.ca
 contributors Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
diff --git a/imports/schedules/helpers/schedules_helper.py b/imports/schedules/helpers/schedules_helper.py
index 33011359..772ffb54 100644
--- a/imports/schedules/helpers/schedules_helper.py
+++ b/imports/schedules/helpers/schedules_helper.py
@@ -24,7 +24,7 @@ class SchedulesHelper:
   @staticmethod
   def comnet_from_usage(usage):
     """
-    Get Comnet usages from the given internal usages key
+    Get Comnet usage from the given internal usage key
     :param usage: str
     :return: str
     """
diff --git a/imports/sensors/concordia_energy_consumption.py b/imports/sensors/concordia_energy_consumption.py
index f60289f6..c9cefd6a 100644
--- a/imports/sensors/concordia_energy_consumption.py
+++ b/imports/sensors/concordia_energy_consumption.py
@@ -14,8 +14,6 @@ class ConcordiaEnergyConsumption(ConcordiaFileReport):
     super().__init__(city, end_point, base_path, 'concordia_energy_db.json')
     for city_object in city.city_objects:
       self._assign_sensor_to_object(city_object)
-    for city_object_cluster in city.city_objects_cluster:
-      self._assign_sensor_to_object(city_object_cluster)
 
   def _assign_sensor_to_object(self, obj):
     for i in range(len(self._city_object)):
@@ -25,7 +23,7 @@ class ConcordiaEnergyConsumption(ConcordiaFileReport):
         building_energy_consumption = pd.concat(building_measures, keys=building_headers, axis=1)
         sensor = ConcordiaEnergySensor(self._sensors[i])
         sensor_exist = False
-        for j in range(len(object.sensors)):
+        for j in range(len(obj.sensors)):
           if obj.sensors[j].name is sensor.name:
             obj.sensors[j].add_period(building_energy_consumption)
             sensor_exist = True
diff --git a/imports/sensors/concordia_file_report.py b/imports/sensors/concordia_file_report.py
index e8b6ef46..25b67ef0 100644
--- a/imports/sensors/concordia_file_report.py
+++ b/imports/sensors/concordia_file_report.py
@@ -10,10 +10,12 @@ from pathlib import Path
 import pandas as pd
 from city_model_structure.attributes.concordia_energy_sensor import ConcordiaEnergySensor
 
+
 class ConcordiaFileReport:
   def __init__(self, city, end_point, base_path, db_file):
 
     self._city_object = []
+    self._city_objects_cluster = []
     self._sensors = []
     self._sensor_point = {}
     self._city = city
diff --git a/imports/sensors/concordia_gas_flow.py b/imports/sensors/concordia_gas_flow.py
index affe4de1..48a22bf1 100644
--- a/imports/sensors/concordia_gas_flow.py
+++ b/imports/sensors/concordia_gas_flow.py
@@ -13,19 +13,21 @@ class ConcordiaGasFlow(ConcordiaFileReport):
   def __init__(self, city, end_point, base_path):
     super().__init__(city, end_point, base_path, 'concordia_gas_flow_db.json')
     for city_object in city.city_objects:
-      for i in range(len(self._city_object)):
-        if self._city_object[i] == city_object.name and self._sensors[i] in self._sensor_point:
-          building_measures = [self._measures["Date time"], self._measures[self._sensor_point[self._sensors[i]]]]
-          building_headers = ["Date time", "Gas Flow Cumulative Monthly"]
-          building_gas_flow = pd.concat(building_measures, keys=building_headers, axis=1)
-          sensor = ConcordiaGasFlowSensor(self._sensors[i])
-          sensor_exist = False
-          for j in range(len(city_object.sensors)):
-            if city_object.sensors[j].name is sensor.name:
-              city_object.sensors[j].add_period(building_gas_flow)
-              sensor_exist = True
-              break
-          if not sensor_exist:
-            sensor.add_period(building_gas_flow)
-            city_object.sensors.append(sensor)
+      self._assign_sensor_to_object(city_object)
 
+  def _assign_sensor_to_object(self, obj):
+    for i in range(len(self._city_object)):
+      if self._city_object[i] == obj.name and self._sensors[i] in self._sensor_point:
+        building_measures = [self._measures["Date time"], self._measures[self._sensor_point[self._sensors[i]]]]
+        building_headers = ["Date time", "Gas Flow Cumulative Monthly"]
+        building_energy_consumption = pd.concat(building_measures, keys=building_headers, axis=1)
+        sensor = ConcordiaGasFlowSensor(self._sensors[i])
+        sensor_exist = False
+        for j in range(len(obj.sensors)):
+          if obj.sensors[j].name is sensor.name:
+            obj.sensors[j].add_period(building_energy_consumption)
+            sensor_exist = True
+            break
+        if not sensor_exist:
+          sensor.add_period(building_energy_consumption)
+          obj.sensors.append(sensor)
diff --git a/imports/sensors/concordia_temperature.py b/imports/sensors/concordia_temperature.py
index 8cc0c0e5..9f5ccc53 100644
--- a/imports/sensors/concordia_temperature.py
+++ b/imports/sensors/concordia_temperature.py
@@ -13,19 +13,21 @@ class ConcordiaTemperature(ConcordiaFileReport):
   def __init__(self, city, end_point, base_path):
     super().__init__(city, end_point, base_path, 'concordia_temperature_db.json')
     for city_object in city.city_objects:
-      for i in range(len(self._city_object)):
-        if self._city_object[i] == city_object.name and self._sensors[i] in self._sensor_point:
-          building_measures = [self._measures["Date time"], self._measures[self._sensor_point[self._sensors[i]]]]
-          building_headers = ["Date time", "Temperature"]
-          building_temperature = pd.concat(building_measures, keys=building_headers, axis=1)
-          sensor = ConcordiaTemperatureSensor(self._sensors[i])
-          sensor_exist = False
-          for j in range(len(city_object.sensors)):
-            if city_object.sensors[j].name is sensor.name:
-              city_object.sensors[j].add_period(building_temperature)
-              sensor_exist = True
-              break
-          if not sensor_exist:
-            sensor.add_period(building_temperature)
-            city_object.sensors.append(sensor)
+      self._assign_sensor_to_object(city_object)
 
+  def _assign_sensor_to_object(self, obj):
+    for i in range(len(self._city_object)):
+      if self._city_object[i] == obj.name and self._sensors[i] in self._sensor_point:
+        building_measures = [self._measures["Date time"], self._measures[self._sensor_point[self._sensors[i]]]]
+        building_headers = ["Date time", "Temperature"]
+        building_energy_consumption = pd.concat(building_measures, keys=building_headers, axis=1)
+        sensor = ConcordiaTemperatureSensor(self._sensors[i])
+        sensor_exist = False
+        for j in range(len(obj.sensors)):
+          if obj.sensors[j].name is sensor.name:
+            obj.sensors[j].add_period(building_energy_consumption)
+            sensor_exist = True
+            break
+        if not sensor_exist:
+          sensor.add_period(building_energy_consumption)
+          obj.sensors.append(sensor)
diff --git a/imports/sensors_factory.py b/imports/sensors_factory.py
index c94d39b6..962b073b 100644
--- a/imports/sensors_factory.py
+++ b/imports/sensors_factory.py
@@ -31,7 +31,7 @@ class SensorsFactory:
 
   def enrich(self):
     """
-    Enrich the city with the usages information
+    Enrich the city with the usage information
     :return: None
     """
     getattr(self, self._handler, lambda: None)()
diff --git a/imports/usages/data_classes/hft_internal_gains_archetype.py b/imports/usage/data_classes/hft_internal_gains_archetype.py
similarity index 100%
rename from imports/usages/data_classes/hft_internal_gains_archetype.py
rename to imports/usage/data_classes/hft_internal_gains_archetype.py
diff --git a/imports/usages/data_classes/hft_usage_zone_archetype.py b/imports/usage/data_classes/hft_usage_zone_archetype.py
similarity index 85%
rename from imports/usages/data_classes/hft_usage_zone_archetype.py
rename to imports/usage/data_classes/hft_usage_zone_archetype.py
index 1d13a84f..493e26ca 100644
--- a/imports/usages/data_classes/hft_usage_zone_archetype.py
+++ b/imports/usage/data_classes/hft_usage_zone_archetype.py
@@ -1,10 +1,10 @@
 """
-HftUsageZoneArchetype stores usages information by building archetypes
+HftUsageZoneArchetype stores usage information by building archetypes
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Pilar Monsalvete pilar_monsalvete@yahoo.es
 """
 from typing import List
-from imports.usages.data_classes.hft_internal_gains_archetype import HftInternalGainsArchetype
+from imports.usage.data_classes.hft_internal_gains_archetype import HftInternalGainsArchetype
 
 
 class HftUsageZoneArchetype:
@@ -34,7 +34,7 @@ class HftUsageZoneArchetype:
   @property
   def internal_gains(self) -> List[HftInternalGainsArchetype]:
     """
-    Get usages zone internal gains
+    Get usage zone internal gains
     :return: [InternalGains]
     """
     return self._internal_gains
@@ -42,7 +42,7 @@ class HftUsageZoneArchetype:
   @property
   def heating_setpoint(self):
     """
-    Get usages zone heating set point in celsius grads
+    Get usage zone heating set point in celsius grads
     :return: float
     """
     return self._heating_setpoint
@@ -50,7 +50,7 @@ class HftUsageZoneArchetype:
   @property
   def heating_setback(self):
     """
-    Get usages zone heating setback in celsius grads
+    Get usage zone heating setback in celsius grads
     :return: float
     """
     return self._heating_setback
@@ -58,7 +58,7 @@ class HftUsageZoneArchetype:
   @property
   def cooling_setpoint(self):
     """
-    Get usages zone cooling setpoint in celsius grads
+    Get usage zone cooling setpoint in celsius grads
     :return: float
     """
     return self._cooling_setpoint
@@ -66,7 +66,7 @@ class HftUsageZoneArchetype:
   @property
   def hours_day(self):
     """
-    Get usages zone usages hours per day
+    Get usage zone usage hours per day
     :return: float
     """
     return self._hours_day
@@ -74,7 +74,7 @@ class HftUsageZoneArchetype:
   @property
   def days_year(self):
     """
-    Get usages zone usages days per year
+    Get usage zone usage days per year
     :return: float
     """
     return self._days_year
@@ -82,7 +82,7 @@ class HftUsageZoneArchetype:
   @property
   def mechanical_air_change(self):
     """
-    Set usages zone mechanical air change in air change per hour (ACH)
+    Set usage zone mechanical air change in air change per hour (ACH)
     :return: float
     """
     return self._mechanical_air_change
@@ -90,7 +90,7 @@ class HftUsageZoneArchetype:
   @property
   def usage(self):
     """
-    Get usages zone usages
+    Get usage zone usage
     :return: str
     """
     return self._usage
diff --git a/imports/usages/helpers/usage_helper.py b/imports/usage/helpers/usage_helper.py
similarity index 90%
rename from imports/usages/helpers/usage_helper.py
rename to imports/usage/helpers/usage_helper.py
index 43476b6e..e1f27e3a 100644
--- a/imports/usages/helpers/usage_helper.py
+++ b/imports/usage/helpers/usage_helper.py
@@ -23,12 +23,12 @@ class UsageHelper:
   @staticmethod
   def hft_from_usage(usage):
     """
-    Get HfT usages from the given internal usages key
+    Get HfT usage from the given internal usage key
     :param usage: str
     :return: str
     """
     try:
       return UsageHelper.usage_to_hft[usage]
     except KeyError:
-      sys.stderr.write('Error: keyword not found. Returned default HfT usages "residential"\n')
+      sys.stderr.write('Error: keyword not found. Returned default HfT usage "residential"\n')
       return UsageHelper.hft_default_value
diff --git a/imports/usages/hft_usage_interface.py b/imports/usage/hft_usage_interface.py
similarity index 97%
rename from imports/usages/hft_usage_interface.py
rename to imports/usage/hft_usage_interface.py
index 2cd43efb..79a3d26f 100644
--- a/imports/usages/hft_usage_interface.py
+++ b/imports/usage/hft_usage_interface.py
@@ -1,12 +1,12 @@
 """
 Hft-based interface, it reads format defined within the CERC team based on that one used in SimStadt and developed by
-the IAF team at hft-Stuttgart and enriches the city with usages parameters
+the IAF team at hft-Stuttgart and enriches the city with usage parameters
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
 import xmltodict
-from imports.usages.data_classes.hft_usage_zone_archetype import HftUsageZoneArchetype as huza
-from imports.usages.data_classes.hft_internal_gains_archetype import HftInternalGainsArchetype as higa
+from imports.usage.data_classes.hft_usage_zone_archetype import HftUsageZoneArchetype as huza
+from imports.usage.data_classes.hft_internal_gains_archetype import HftInternalGainsArchetype as higa
 
 
 class HftUsageInterface:
diff --git a/imports/usages/hft_usage_parameters.py b/imports/usage/hft_usage_parameters.py
similarity index 92%
rename from imports/usages/hft_usage_parameters.py
rename to imports/usage/hft_usage_parameters.py
index f4dfb924..40b2883b 100644
--- a/imports/usages/hft_usage_parameters.py
+++ b/imports/usage/hft_usage_parameters.py
@@ -1,12 +1,12 @@
 """
-HftUsageParameters model the usages properties
+HftUsageParameters model the usage properties
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
 import sys
 
 from imports.geometry.helpers.geometry_helper import GeometryHelper as gh
-from imports.usages.hft_usage_interface import HftUsageInterface
+from imports.usage.hft_usage_interface import HftUsageInterface
 from city_model_structure.attributes.usage_zone import UsageZone
 from city_model_structure.attributes.internal_gains import InternalGains
 
@@ -25,7 +25,7 @@ class HftUsageParameters(HftUsageInterface):
 
   def enrich_buildings(self):
     """
-    Returns the city with the usages parameters assigned to the buildings
+    Returns the city with the usage parameters assigned to the buildings
     :return:
     """
     city = self._city
@@ -33,10 +33,10 @@ class HftUsageParameters(HftUsageInterface):
       archetype = self._search_archetype(gh.usage_from_function(building.function))
       if archetype is None:
         sys.stderr.write(f'Building {building.name} has unknown archetype for building function:'
-                         f' {building.function}, that assigns building usages as '
+                         f' {building.function}, that assigns building usage as '
                          f'{gh.usage_from_function(building.function)}\n')
         continue
-      # todo: what to do with mix-usages usages from gml?
+      # todo: what to do with mix-usage usage from gml?
       mix_usage = False
       if not mix_usage:
         # just one usage_zone
diff --git a/imports/usage_factory.py b/imports/usage_factory.py
index 90e708b3..190d5bf3 100644
--- a/imports/usage_factory.py
+++ b/imports/usage_factory.py
@@ -1,10 +1,10 @@
 """
-UsageFactory retrieve the specific usages module for the given region
+UsageFactory retrieve the specific usage module for the given region
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Guille Gutierrez guillermo.gutierrezmorote@concordia.ca
 """
 from pathlib import Path
-from imports.usages.hft_usage_parameters import HftUsageParameters
+from imports.usage.hft_usage_parameters import HftUsageParameters
 
 
 class UsageFactory:
@@ -24,7 +24,7 @@ class UsageFactory:
 
   def enrich(self):
     """
-    Enrich the city with the usages information
+    Enrich the city with the usage information
     :return: None
     """
     getattr(self, self._handler, lambda: None)()
diff --git a/imports/weather_factory.py b/imports/weather_factory.py
index 91f30db9..b0f99e65 100644
--- a/imports/weather_factory.py
+++ b/imports/weather_factory.py
@@ -39,7 +39,7 @@ class WeatherFactory:
 
   def enrich(self):
     """
-    Enrich the city with the usages information
+    Enrich the city with the usage information
     :return: None
     """
     getattr(self, self._handler, lambda: None)()
diff --git a/non_functional_tests/test_sensors_factory.py b/non_functional_tests/test_sensors_factory.py
index 50144a6a..cb5a08e3 100644
--- a/non_functional_tests/test_sensors_factory.py
+++ b/non_functional_tests/test_sensors_factory.py
@@ -8,7 +8,7 @@ from unittest import TestCase
 import pandas as pd
 from city_model_structure.city import City
 from city_model_structure.building import Building
-from city_model_structure.city_object import CityObject
+from city_model_structure.buildings_cluster import BuildingsCluster
 from imports.sensors_factory import SensorsFactory
 
 
@@ -39,23 +39,18 @@ class TestSensorsFactory(TestCase):
     city = City(lower_corner, upper_corner, srs_name)
     buildings.append(Building("EV", lod, surfaces, year_of_construction, function, lower_corner))
     buildings.append(Building("GM", lod, surfaces, year_of_construction, function, lower_corner))
+    buildings.append(Building("MB", lod, surfaces, year_of_construction, function, lower_corner))
     for building in buildings:
       city.add_city_object(building)
+    buildings_cluster = BuildingsCluster("GM_MB_EV", buildings)
+    city.add_city_objects_cluster(buildings_cluster)
     return city
-    #virtual_building = CityObject("GM_MB_EV", lod, surfaces, lower_corner)
-    #virtual_building.type = 'Virtual'
-    #city.add_city_object(virtual_building)
 
   def test_city_with_sensors(self):
     SensorsFactory('cec', self._city, self._end_point).enrich()
     SensorsFactory('cgf', self._city, self._end_point).enrich()
     SensorsFactory('ct', self._city, self._end_point).enrich()
     for city_object in self._city.city_objects:
+      print(city_object.name, len(city_object.sensors))
       for sensor in city_object.sensors:
-        # force update last row
-        update = pd.DataFrame([['2020-01-19 23:55:00', '12345.0']], columns=["Date time", "Energy consumption"])
-        update = update.astype({"Date time": 'datetime64', "Energy consumption": 'float64'})
-        sensor.add_period(update)
-
-        row = sensor.measures.loc[sensor.measures["Date time"] == '2020-01-19 23:55:00']['Energy consumption'].iloc[0]
-        self.assertTrue(f'{row}' == '12345.0')
+        print(sensor.name)
diff --git a/non_functional_tests/test_usage_factory.py b/non_functional_tests/test_usage_factory.py
index e46cd50f..2d13d4e5 100644
--- a/non_functional_tests/test_usage_factory.py
+++ b/non_functional_tests/test_usage_factory.py
@@ -1,5 +1,5 @@
 """
-TestUsageFactory test and validate the city model structure usages parameters
+TestUsageFactory test and validate the city model structure usage parameters
 SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2020 Project Author Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
@@ -31,7 +31,7 @@ class TestUsageFactory(TestCase):
 
   def test_city_with_usage(self):
     """
-    Enrich the city with the usages information and verify it
+    Enrich the city with the usage information and verify it
     :return: None
     """
     file = 'pluto_building.gml'
@@ -44,14 +44,14 @@ class TestUsageFactory(TestCase):
     for building in city.buildings:
       self.assertIsNotNone(building.usage_zones, 'usage_zones not created')
       for usage_zone in building.usage_zones:
-        self.assertIsNotNone(usage_zone.usage, 'usages is none')
-        self.assertIsNotNone(usage_zone.internal_gains, 'usages is none')
-        self.assertIsNotNone(usage_zone.cooling_setpoint, 'usages is none')
-        self.assertIsNotNone(usage_zone.heating_setback, 'usages is none')
-        self.assertIsNotNone(usage_zone.heating_setpoint, 'usages is none')
-        self.assertIsNotNone(usage_zone.occupancy_density, 'usages is none')
-        self.assertIsNotNone(usage_zone.hours_day, 'usages is none')
-        self.assertIsNotNone(usage_zone.days_year, 'usages is none')
-        self.assertIsNotNone(usage_zone.dhw_average_volume_pers_day, 'usages is none')
-        self.assertIsNotNone(usage_zone.dhw_preparation_temperature, 'usages is none')
-        self.assertIsNotNone(usage_zone.electrical_app_average_consumption_sqm_year, 'usages is none')
+        self.assertIsNotNone(usage_zone.usage, 'usage is none')
+        self.assertIsNotNone(usage_zone.internal_gains, 'usage is none')
+        self.assertIsNotNone(usage_zone.cooling_setpoint, 'usage is none')
+        self.assertIsNotNone(usage_zone.heating_setback, 'usage is none')
+        self.assertIsNotNone(usage_zone.heating_setpoint, 'usage is none')
+        self.assertIsNotNone(usage_zone.occupancy_density, 'usage is none')
+        self.assertIsNotNone(usage_zone.hours_day, 'usage is none')
+        self.assertIsNotNone(usage_zone.days_year, 'usage is none')
+        self.assertIsNotNone(usage_zone.dhw_average_volume_pers_day, 'usage is none')
+        self.assertIsNotNone(usage_zone.dhw_preparation_temperature, 'usage is none')
+        self.assertIsNotNone(usage_zone.electrical_app_average_consumption_sqm_year, 'usage is none')