diff --git a/hub/exports/user_factory.py b/hub/exports/user_factory.py
index 0c932418..cb3d5121 100644
--- a/hub/exports/user_factory.py
+++ b/hub/exports/user_factory.py
@@ -4,7 +4,7 @@ SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2022 Concordia CERC group
 Project CoderPeter Yefi peteryefi@gmail.com
 """
-from hub.persistence import UserRepo
+from hub.persistence import User
 
 
 class UserFactory:
@@ -13,19 +13,21 @@ class UserFactory:
   """
 
   def __init__(self, db_name, app_env, dotenv_path):
-    self._user_repo = UserRepo(db_name=db_name, app_env=app_env, dotenv_path=dotenv_path)
+    self._user_repo = User(db_name=db_name, app_env=app_env, dotenv_path=dotenv_path)
 
-  def login_user(self, email: str, password: str):
+  def login_user(self, name: str,  password: str, application_id: int):
     """
     Retrieve a single city from postgres
-    :param email: the email of the user
+    :param name: the email of the user
     :param password: the password of the user
+    :param application_id: the id of the application accessing hub
     """
-    return self._user_repo.get_user_by_email_and_password(email, password)
+    return self._user_repo.get_by_name_application_and_password(name, password, application_id)
 
-  def get_user_by_email(self, email):
+  def get_by_name_and_application(self, name: str, application: int):
     """
     Retrieve a single user
-    :param email: the email of the user to get
+    :param name: user name
+    :param application: application accessing hub
     """
-    return self._user_repo.get_by_email(email)
+    return self._user_repo.get_by_name_and_application(name, application)
diff --git a/hub/hub_logger/__init__.py b/hub/hub_logger/__init__.py
index e4d66f89..4c3dd95c 100644
--- a/hub/hub_logger/__init__.py
+++ b/hub/hub_logger/__init__.py
@@ -6,7 +6,8 @@ log_dir = (Path(__file__).parent.parent / 'logs').resolve()
 log_file = (log_dir / 'hub.log').resolve()
 try:
   if not os.path.isfile(log_file):
-    os.mkdir(log_dir)
+    if not os.path.exists:
+      os.mkdir(log_dir)
     with open(log_file, 'x'):
       pass
   logger.basicConfig(filename=log_file, format="%(asctime)s:%(levelname)s:{%(pathname)s:%(funcName)s:%(lineno)d} "
diff --git a/hub/imports/db_factory.py b/hub/imports/db_factory.py
index 67891f30..e58ce073 100644
--- a/hub/imports/db_factory.py
+++ b/hub/imports/db_factory.py
@@ -7,6 +7,7 @@ Project CoderPeter Yefi peteryefi@gmail.com
 from hub.city_model_structure.city import City
 from hub.persistence import City as CityRepository
 from hub.persistence import SimulationResults
+from hub.persistence import Application
 
 
 class DBFactory:
@@ -17,6 +18,7 @@ class DBFactory:
   def __init__(self, db_name, dotenv_path, app_env):
     self._city_repository = CityRepository(db_name=db_name, dotenv_path=dotenv_path, app_env=app_env)
     self._simulation_results = SimulationResults(db_name=db_name, dotenv_path=dotenv_path, app_env=app_env)
+    self._application = Application(db_name=db_name, dotenv_path=dotenv_path, app_env=app_env)
 
   def persist_city(self, city: City, pickle_path, application_id: int, user_id: int):
     """
@@ -36,6 +38,24 @@ class DBFactory:
     """
     return self._city_repository.update(city_id, city)
 
+  def persist_application(self, name: str, description: str, application_uuid: str):
+    """
+    Creates an application
+   :param name: name of application
+   :param description: the description of the application
+   :param application_uuid: the uuid of the application to be created
+    """
+    return self._application.insert(name, description, application_uuid)
+
+  def update_application(self, name: str, description: str, application_uuid: str):
+    """
+    Update an application
+   :param name: name of application
+   :param description: the description of the application
+   :param application_uuid: the uuid of the application to be created
+    """
+    return self._application.update(application_uuid, name, description)
+
   def delete_city(self, city_id):
     """
     Deletes a single city from postgres
@@ -43,6 +63,13 @@ class DBFactory:
     """
     self._city_repository.delete(city_id)
 
+  def delete_application(self, application_uuid):
+    """
+    Deletes a single application from postgres
+    :param application_uuid: the id of the application to get
+    """
+    self._application.delete(application_uuid)
+
   def add_simulation_results(self, name, values, city_id=None, city_object_id=None):
     """
     Add simulation results to the city or to the city_object
diff --git a/hub/imports/user_factory.py b/hub/imports/user_factory.py
index 3d900c1f..5053a6e6 100644
--- a/hub/imports/user_factory.py
+++ b/hub/imports/user_factory.py
@@ -4,7 +4,7 @@ SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2022 Concordia CERC group
 Project CoderPeter Yefi peteryefi@gmail.com
 """
-from hub.persistence import UserRepo
+from hub.persistence import User as UserRepository
 from hub.persistence import UserRoles
 
 
@@ -14,19 +14,19 @@ class UserFactory:
   """
 
   def __init__(self, db_name, app_env, dotenv_path):
-    self._user_repo = UserRepo(db_name=db_name, app_env=app_env, dotenv_path=dotenv_path)
+    self._user_repo = UserRepository(db_name=db_name, app_env=app_env, dotenv_path=dotenv_path)
 
-  def create_user(self, name: str, email: str, password: str, role: UserRoles):
+  def create_user(self, name: str, application_id: int, password: str, role: UserRoles):
     """
     Creates a new user
     :param name: the name of the user
-    :param email: the email of the user
+    :param application_id: the application id of the user
     :param password: the password of the user
     :param role: the role of the user
     """
-    return self._user_repo.insert(name, email, password, role)
+    return self._user_repo.insert(name, password, role, application_id)
 
-  def update_user(self, user_id: int, name: str, email: str, password: str, role: UserRoles):
+  def update_user(self, user_id: int, name: str, password: str, role: UserRoles):
     """
     Creates a new user
     :param user_id: the id of the user
@@ -35,11 +35,11 @@ class UserFactory:
     :param password: the password of the user
     :param role: the role of the user
     """
-    return self._user_repo.update(user_id, name, email, password, role)
+    return self._user_repo.update(user_id, name, password, role)
 
   def delete_user(self, user_id):
     """
     Retrieve a single user
     :param user_id: the id of the user to delete
     """
-    return self._user_repo.delete_user(user_id)
+    return self._user_repo.delete(user_id)
diff --git a/hub/persistence/models/simulation_results.py b/hub/persistence/models/simulation_results.py
index defc3e7e..d4dea88d 100644
--- a/hub/persistence/models/simulation_results.py
+++ b/hub/persistence/models/simulation_results.py
@@ -12,6 +12,7 @@ from sqlalchemy import DateTime
 from sqlalchemy.dialects.postgresql import JSONB
 from hub.persistence.configuration import Models
 
+
 class SimulationResults(Models):
   """
   A model representation of an application
diff --git a/hub/persistence/repositories/application.py b/hub/persistence/repositories/application.py
index 91d720ec..2aaecd5c 100644
--- a/hub/persistence/repositories/application.py
+++ b/hub/persistence/repositories/application.py
@@ -42,6 +42,7 @@ class Application(Repository):
     if application is None:
       try:
         application = Model(name=name, description=description, application_uuid=application_uuid)
+
         self.session.add(application)
         self.session.commit()
         return application
diff --git a/hub/persistence/repositories/city.py b/hub/persistence/repositories/city.py
index a1459c96..83a42e6d 100644
--- a/hub/persistence/repositories/city.py
+++ b/hub/persistence/repositories/city.py
@@ -6,7 +6,6 @@ Project Coder Peter Yefi peteryefi@gmail.com
 """
 
 import datetime
-import pickle
 from typing import Union, Dict
 
 from sqlalchemy import select
@@ -60,8 +59,9 @@ class City(Repository):
       for building in city.buildings:
         object_usage = ''
         for internal_zone in building.internal_zones:
-          for usage in internal_zone.usages:
-            object_usage = f'{object_usage}{usage.name}_{usage.percentage} '
+          if internal_zone.usages is not None:
+            for usage in internal_zone.usages:
+              object_usage = f'{object_usage}{usage.name}_{usage.percentage} '
         object_usage = object_usage.rstrip()
         db_city_object = CityObject(db_city.id,
                                     building.name,
@@ -101,6 +101,7 @@ class City(Repository):
     :return: a city
     """
     try:
+      self.session.query(CityObject).filter(CityObject.city_id == city_id).delete()
       self.session.query(Model).filter(Model.id == city_id).delete()
       self.session.commit()
     except SQLAlchemyError as err:
diff --git a/hub/unittests/test_db_factory.py b/hub/unittests/test_db_factory.py
index 2a8c0719..a4544a6b 100644
--- a/hub/unittests/test_db_factory.py
+++ b/hub/unittests/test_db_factory.py
@@ -9,12 +9,12 @@ from hub.imports.geometry_factory import GeometryFactory
 from hub.imports.db_factory import DBFactory
 from hub.imports.user_factory import UserFactory
 from hub.exports.db_factory import DBFactory as ExportDBFactory
-from hub.persistence.base_repo import BaseRepo
+from hub.persistence.repository import Repository
 from sqlalchemy import create_engine
-from hub.persistence.models import City
+from hub.persistence.models import City, Application, CityObject
 from hub.persistence.models import User, UserRoles
-from pickle import loads
 from sqlalchemy.exc import ProgrammingError
+import uuid
 
 
 class TestDBFactory(TestCase):
@@ -29,8 +29,8 @@ class TestDBFactory(TestCase):
     :return: None
     """
     # Create test database
-    repo = BaseRepo(db_name='test_db', app_env='TEST', dotenv_path='/usr/local/etc/hub/.env')
-    eng = create_engine(f'postgresql://{repo.config.get_db_user()}@/{repo.config.get_db_user()}')
+    repo = Repository(db_name='test_db', app_env='TEST', dotenv_path='/usr/local/etc/hub/.env')
+    eng = create_engine(f'postgresql://{repo.configuration.get_db_user()}@/{repo.configuration.get_db_user()}')
 
     try:
       # delete test database if it exists
@@ -45,56 +45,58 @@ class TestDBFactory(TestCase):
     cnn.execute('commit')
     cnn.execute("CREATE DATABASE test_db")
     cnn.close()
+
+    Application.__table__.create(bind=repo.engine, checkfirst=True)
     User.__table__.create(bind=repo.engine, checkfirst=True)
     City.__table__.create(bind=repo.engine, checkfirst=True)
+    CityObject.__table__.create(bind=repo.engine, checkfirst=True)
 
     city_file = "tests_data/C40_Final.gml"
     cls.city = GeometryFactory('citygml', city_file).city
     cls._db_factory = DBFactory(db_name='test_db', app_env='TEST', dotenv_path='../.env')
     cls._export_db_factory = ExportDBFactory(db_name='test_db', app_env='TEST', dotenv_path='../.env')
     user_factory = UserFactory(db_name='test_db', app_env='TEST', dotenv_path='../.env')
-    cls._user = user_factory.create_user("Admin", "admin@hub.com", "Admin@123", UserRoles.Admin)
+    cls.unique_id = str(uuid.uuid4())
+    cls.application = cls._db_factory.persist_application("test", "test application", cls.unique_id)
+    cls._user = user_factory.create_user("Admin", cls.application.id, "Admin@123", UserRoles.Admin)
+    cls.pickle_path = 'tests_data/pickle_path.bz2'
+
+  def test_save_application(self):
+    self.assertEqual(self.application.name, "test")
+    self.assertEqual(self.application.description, "test application")
+    self.assertEqual(str(self.application.application_uuid), self.unique_id)
 
   def test_save_city(self):
-    saved_city = self._db_factory.persist_city(self._user.id, self.city)
+    self.city.name = "Montréal"
+    saved_city = self._db_factory.persist_city(self.city, self.pickle_path, self.application.id, self._user.id)
     self.assertEqual(saved_city.name, 'Montréal')
-    pickled_city = loads(saved_city.city)
-    self.assertEqual(len(pickled_city.buildings), 10)
-    self.assertEqual(pickled_city.buildings[0].floor_area, 1990.9913970530033)
+    self.assertEqual(saved_city.pickle_path, self.pickle_path)
+    self.assertEqual(saved_city.level_of_detail, self.city.level_of_detail.geometry)
     self._db_factory.delete_city(saved_city.id)
 
-  def test_save_same_city_with_same_hub_version(self):
-    first_city = self._db_factory.persist_city(self._user.id, self.city)
-    second_city = self._db_factory.persist_city(self._user.id, self.city)
-    self.assertEqual(second_city['message'], f'Same version of {self.city.name} exist')
-    self.assertEqual(first_city.name, 'Montréal')
-    self.assertEqual(first_city.country_code, 'ca')
-    self._db_factory.delete_city(first_city.id)
-
   def test_get_city_by_name(self):
-    city = self._db_factory.persist_city(self._user.id, self.city)
+    city = self._db_factory.persist_city(self.city, self.pickle_path, self.application.id, self._user.id)
     retrieved_city = self._export_db_factory.get_city_by_name(city.name)
-    self.assertEqual(retrieved_city[0].lower_corner[0], 610610.7547462888)
-    self._db_factory.delete_city(city.id)
-
-  def test_get_city_by_user(self):
-    city = self._db_factory.persist_city(self._user.id, self.city)
-    retrieved_city = self._export_db_factory.get_city_by_user(self._user.id)
+    self.assertEqual(retrieved_city[0].application_id, 1)
     self.assertEqual(retrieved_city[0].user_id, self._user.id)
     self._db_factory.delete_city(city.id)
 
+  def test_get_city_by_user(self):
+    city = self._db_factory.persist_city(self.city, self.pickle_path, self.application.id, self._user.id)
+    retrieved_city = self._export_db_factory.get_city_by_user(self._user.id)
+    self.assertEqual(retrieved_city[0].pickle_path, self.pickle_path)
+    self._db_factory.delete_city(city.id)
+
   def test_get_city_by_id(self):
-    city = self._db_factory.persist_city(self._user.id, self.city)
+    city = self._db_factory.persist_city(self.city, self.pickle_path, self.application.id, self._user.id)
     retrieved_city = self._export_db_factory.get_city(city.id)
-    self.assertEqual(retrieved_city.upper_corner[0], 610818.6731258357)
+    self.assertEqual(retrieved_city.level_of_detail, self.city.level_of_detail.geometry)
     self._db_factory.delete_city(city.id)
 
   def test_get_update_city(self):
-    city = self._db_factory.persist_city(self._user.id, self.city)
-    self.city.longitude = 1.43589
-    self.city.latitude = -9.38928339
+    city = self._db_factory.persist_city(self.city, self.pickle_path, self.application.id, self._user.id)
+    self.city.name = "Ottawa"
     self._db_factory.update_city(city.id, self.city)
     updated_city = self._export_db_factory.get_city(city.id)
-    self.assertEqual(updated_city.longitude, 1.43589)
-    self.assertEqual(updated_city.latitude, -9.38928339)
+    self.assertEqual(updated_city.name, self.city.name)
     self._db_factory.delete_city(city.id)
diff --git a/hub/unittests/tests_data/pickle_path.bz2 b/hub/unittests/tests_data/pickle_path.bz2
new file mode 100644
index 00000000..b4916489
Binary files /dev/null and b/hub/unittests/tests_data/pickle_path.bz2 differ