diff --git a/hub/catalog_factories/construction/nrel_catalog.py b/hub/catalog_factories/construction/nrel_catalog.py
index bf1374af..c9235cfe 100644
--- a/hub/catalog_factories/construction/nrel_catalog.py
+++ b/hub/catalog_factories/construction/nrel_catalog.py
@@ -40,7 +40,7 @@ class NrelCatalog(Catalog):
     _catalog_windows = []
     windows = self._constructions['library']['windows']['window']
     for window in windows:
-      frame_ratio = window['frame_ratio']['#text']
+      frame_ratio = float(window['frame_ratio']['#text'])
       g_value = window['shgc']
       overall_u_value = float(window['conductivity']['#text']) / float(window['thickness']['#text'])
       name = window['@name']
@@ -54,9 +54,9 @@ class NrelCatalog(Catalog):
     for material in materials:
       material_id = material['@id']
       name = material['@name']
-      solar_absorptance = material['solar_absorptance']['#text']
-      thermal_absorptance = material['thermal_absorptance']['#text']
-      visible_absorptance = material['visible_absorptance']['#text']
+      solar_absorptance = float(material['solar_absorptance']['#text'])
+      thermal_absorptance = float(material['thermal_absorptance']['#text'])
+      visible_absorptance = float(material['visible_absorptance']['#text'])
       no_mass = False
       thermal_resistance = None,
       conductivity = None,
@@ -64,11 +64,11 @@ class NrelCatalog(Catalog):
       specific_heat = None
       if 'no_mass' in material and material['no_mass'] == 'true':
         no_mass = True
-        thermal_resistance = material['thermal_resistance']['#text']
+        thermal_resistance = float(material['thermal_resistance']['#text'])
       else:
-        conductivity = material['conductivity']['#text']
-        density = material['density']['#text']
-        specific_heat = material['specific_heat']['#text']
+        conductivity = float(material['conductivity']['#text'])
+        density = float(material['density']['#text'])
+        specific_heat = float(material['specific_heat']['#text'])
       _material = Material(material_id,
                            name,
                            solar_absorptance,
@@ -96,7 +96,7 @@ class NrelCatalog(Catalog):
         material_id = layer['material'][0]
         thickness = 0
         if 'thickness' in layer:
-          thickness = layer['thickness']['#text']
+          thickness = float(layer['thickness']['#text'])
         for material in self._catalog_materials:
           if str(material_id) == str(material.id):
             layers.append(Layer(layer_id, layer_name, material, thickness))
@@ -114,18 +114,20 @@ class NrelCatalog(Catalog):
       climate_zone = archetype['@climate_zone']
       construction_period = \
         ConstructionHelper().reference_standard_to_construction_period[archetype['@reference_standard']]
-      average_storey_height = archetype['average_storey_height']['#text']
-      thermal_capacity = str(float(archetype['thermal_capacity']['#text']) * 1000)
-      extra_loses_due_to_thermal_bridges = archetype['extra_loses_due_to_thermal_bridges']['#text']
-      indirect_heated_ratio = archetype['indirect_heated_ratio']['#text']
-      infiltration_rate_for_ventilation_system_off = archetype['infiltration_rate_for_ventilation_system_off']['#text']
-      infiltration_rate_for_ventilation_system_on = archetype['infiltration_rate_for_ventilation_system_on']['#text']
+      average_storey_height = float(archetype['average_storey_height']['#text'])
+      thermal_capacity = float(archetype['thermal_capacity']['#text']) * 1000
+      extra_loses_due_to_thermal_bridges = float(archetype['extra_loses_due_to_thermal_bridges']['#text'])
+      indirect_heated_ratio = float(archetype['indirect_heated_ratio']['#text'])
+      infiltration_rate_for_ventilation_system_off = \
+        float(archetype['infiltration_rate_for_ventilation_system_off']['#text'])
+      infiltration_rate_for_ventilation_system_on = \
+        float(archetype['infiltration_rate_for_ventilation_system_on']['#text'])
 
       archetype_constructions = []
       for archetype_construction in archetype['constructions']['construction']:
         for construction in self._catalog_constructions:
           if construction.id == archetype_construction['@id']:
-            window_ratio = archetype_construction['window_ratio']['#text']
+            window_ratio = float(archetype_construction['window_ratio']['#text'])
             window_id = archetype_construction['window']
             _construction = None
             _window = None
diff --git a/hub/city_model_structure/attributes/plane.py b/hub/city_model_structure/attributes/plane.py
index 700be8fb..8dc0fa77 100644
--- a/hub/city_model_structure/attributes/plane.py
+++ b/hub/city_model_structure/attributes/plane.py
@@ -55,7 +55,7 @@ class Plane:
       self._equation = (a, b, c, d)
     return self._equation
 
-  def distance(self, point):
+  def distance_to_point(self, point):
     """
     Distance between the given point and the plane
     :return: float
diff --git a/hub/city_model_structure/building.py b/hub/city_model_structure/building.py
index d5129142..e2a30906 100644
--- a/hub/city_model_structure/building.py
+++ b/hub/city_model_structure/building.py
@@ -441,3 +441,26 @@ class Building(CityObject):
       for usage in internal_zone.usages:
         _usage = f'{_usage}{usage.name}_{usage.percentage} '
     return _usage.rstrip()
+
+  def identify_shared_walls(self):
+    """
+    Identifies which building' walls adjoin the neighbouring building and saves that information in the
+    corresponding surfaces
+    """
+    x = int((self.upper_corner[0] - self.lower_corner[0]) / 2)
+    y = int((self.upper_corner[1] - self.lower_corner[1]) / 2)
+    city_map = [['' for _ in range(y+1)] for _ in range(x+1)]
+    city_image = [[0 for _ in range(y+1)] for _ in range(x+1)]
+    for building_name in building_names:
+      building = city.city_object(building_name)
+      for ground in building.grounds:
+        length = len(ground.perimeter_polygon.coordinates) - 1
+        for i, coordinate in enumerate(ground.perimeter_polygon.coordinates):
+          j = i+1
+          if i == length:
+            j = 0
+          next_coordinate = ground.perimeter_polygon.coordinates[j]
+          point_1 = GeometryHelper.coordinate_to_map_point(coordinate, city)
+          point_2 = GeometryHelper.coordinate_to_map_point(next_coordinate, city)
+          for x in range(point_1.x, point_2.x):
+            y = GeometryHelper.point_between_point(point_1, point_2, x).y
diff --git a/hub/city_model_structure/building_demand/thermal_zone.py b/hub/city_model_structure/building_demand/thermal_zone.py
index db873ce4..beb26045 100644
--- a/hub/city_model_structure/building_demand/thermal_zone.py
+++ b/hub/city_model_structure/building_demand/thermal_zone.py
@@ -510,10 +510,14 @@ class ThermalZone:
           _schedule.values = values[:day]
           _schedules.append(_schedule)
 
-      _internal_gain.convective_fraction = _convective_fraction / _average_internal_gain
-      _internal_gain.radiative_fraction = _radiative_fraction / _average_internal_gain
-      _internal_gain.latent_fraction = _latent_fraction / _average_internal_gain
       _internal_gain.average_internal_gain = _average_internal_gain
+      _internal_gain.convective_fraction = 0
+      _internal_gain.radiative_fraction = 0
+      _internal_gain.latent_fraction = 0
+      if _average_internal_gain != 0:
+        _internal_gain.convective_fraction = _convective_fraction / _average_internal_gain
+        _internal_gain.radiative_fraction = _radiative_fraction / _average_internal_gain
+        _internal_gain.latent_fraction = _latent_fraction / _average_internal_gain
       _internal_gain.type = 'mean_value'
       _internal_gain.schedules = _schedules
       self._internal_gains = [_internal_gain]
diff --git a/hub/city_model_structure/building_demand/usage.py b/hub/city_model_structure/building_demand/usage.py
index f623ee91..36240038 100644
--- a/hub/city_model_structure/building_demand/usage.py
+++ b/hub/city_model_structure/building_demand/usage.py
@@ -91,9 +91,13 @@ class Usage:
                               + self.occupancy.sensible_radiative_internal_gain
                               + self.occupancy.latent_internal_gain)
           _internal_gain.average_internal_gain = _total_heat_gain
-          _internal_gain.latent_fraction = self.occupancy.latent_internal_gain / _total_heat_gain
-          _internal_gain.radiative_fraction = self.occupancy.sensible_radiative_internal_gain / _total_heat_gain
-          _internal_gain.convective_fraction = self.occupancy.sensible_convective_internal_gain / _total_heat_gain
+          _internal_gain.latent_fraction = 0
+          _internal_gain.radiative_fraction = 0
+          _internal_gain.convective_fraction = 0
+          if _total_heat_gain != 0:
+            _internal_gain.latent_fraction = self.occupancy.latent_internal_gain / _total_heat_gain
+            _internal_gain.radiative_fraction = self.occupancy.sensible_radiative_internal_gain / _total_heat_gain
+            _internal_gain.convective_fraction = self.occupancy.sensible_convective_internal_gain / _total_heat_gain
           _internal_gain.schedules = self.occupancy.occupancy_schedules
           self._internal_gains = [_internal_gain]
       if self.lighting is not None:
diff --git a/hub/city_model_structure/building_demand/usage_zone.py b/hub/city_model_structure/building_demand/usage_zone.py
index 43a69c20..6357cff8 100644
--- a/hub/city_model_structure/building_demand/usage_zone.py
+++ b/hub/city_model_structure/building_demand/usage_zone.py
@@ -91,9 +91,13 @@ class UsageZone:
                               + self.occupancy.sensible_radiative_internal_gain
                               + self.occupancy.latent_internal_gain)
           _internal_gain.average_internal_gain = _total_heat_gain
-          _internal_gain.latent_fraction = self.occupancy.latent_internal_gain / _total_heat_gain
-          _internal_gain.radiative_fraction = self.occupancy.sensible_radiative_internal_gain / _total_heat_gain
-          _internal_gain.convective_fraction = self.occupancy.sensible_convective_internal_gain / _total_heat_gain
+          _internal_gain.latent_fraction = 0
+          _internal_gain.radiative_fraction = 0
+          _internal_gain.convective_fraction = 0
+          if _total_heat_gain != 0:
+            _internal_gain.latent_fraction = self.occupancy.latent_internal_gain / _total_heat_gain
+            _internal_gain.radiative_fraction = self.occupancy.sensible_radiative_internal_gain / _total_heat_gain
+            _internal_gain.convective_fraction = self.occupancy.sensible_convective_internal_gain / _total_heat_gain
           _internal_gain.schedules = self.occupancy.occupancy_schedules
           self._internal_gains = [_internal_gain]
       if self.lighting is not None:
diff --git a/hub/city_model_structure/city_object.py b/hub/city_model_structure/city_object.py
index b5b84fcc..ab50250c 100644
--- a/hub/city_model_structure/city_object.py
+++ b/hub/city_model_structure/city_object.py
@@ -24,11 +24,15 @@ class CityObject:
     self._surfaces = surfaces
     self._type = None
     self._city_object_lower_corner = None
+    self._city_object_upper_corner = None
     self._detailed_polyhedron = None
     self._simplified_polyhedron = None
     self._min_x = ConfigurationHelper().max_coordinate
     self._min_y = ConfigurationHelper().max_coordinate
     self._min_z = ConfigurationHelper().max_coordinate
+    self._max_x = ConfigurationHelper().min_coordinate
+    self._max_y = ConfigurationHelper().min_coordinate
+    self._max_z = ConfigurationHelper().min_coordinate
     self._centroid = None
     self._external_temperature = dict()
     self._global_horizontal = dict()
@@ -212,6 +216,16 @@ class CityObject:
       self._city_object_lower_corner = [self._min_x, self._min_y, self._min_z]
     return self._city_object_lower_corner
 
+  @property
+  def upper_corner(self):
+    """
+    Get city object upper corner coordinates [x, y, z]
+    :return: [x,y,z]
+    """
+    if self._city_object_upper_corner is None:
+      self._city_object_upper_corner = [self._max_x, self._max_y, self._max_z]
+    return self._city_object_upper_corner
+
   @property
   def sensors(self) -> List[Sensor]:
     """
diff --git a/hub/exports/building_energy/idf.py b/hub/exports/building_energy/idf.py
index e33a6d34..b4a63a7d 100644
--- a/hub/exports/building_energy/idf.py
+++ b/hub/exports/building_energy/idf.py
@@ -130,10 +130,7 @@ class Idf:
       self._idf.newidfobject(self._MATERIAL_NOMASS,
                              Name=layer.material.name,
                              Roughness=self._ROUGHNESS,
-                             Thermal_Resistance=layer.material.thermal_resistance,
-                             Thermal_Absorptance=layer.material.thermal_absorptance,
-                             Solar_Absorptance=layer.material.solar_absorptance,
-                             Visible_Absorptance=layer.material.visible_absorptance
+                             Thermal_Resistance=layer.material.thermal_resistance
                              )
     else:
       self._idf.newidfobject(self._MATERIAL,
@@ -323,9 +320,12 @@ class Idf:
 
   def _add_occupancy(self, thermal_zone, zone_name):
     number_of_people = thermal_zone.occupancy.occupancy_density * thermal_zone.total_floor_area
-    fraction_radiant = thermal_zone.occupancy.sensible_radiative_internal_gain / \
-                       (thermal_zone.occupancy.sensible_radiative_internal_gain +
-                        thermal_zone.occupancy.sensible_convective_internal_gain)
+    fraction_radiant = 0
+    total_sensible = thermal_zone.occupancy.sensible_radiative_internal_gain + \
+                     thermal_zone.occupancy.sensible_convective_internal_gain
+    if total_sensible != 0:
+      fraction_radiant = thermal_zone.occupancy.sensible_radiative_internal_gain / total_sensible
+
     self._idf.newidfobject(self._PEOPLE,
                            Name=f'{zone_name}_occupancy',
                            Zone_or_ZoneList_Name=zone_name,
@@ -377,7 +377,6 @@ class Idf:
     self._rename_building(self._city.name)
     self._lod = self._city.level_of_detail.geometry
     for building in self._city.buildings:
-
       for internal_zone in building.internal_zones:
         for thermal_zone in internal_zone.thermal_zones:
           for thermal_boundary in thermal_zone.thermal_boundaries:
diff --git a/hub/exports/building_energy/insel/insel_monthly_energy_balance.py b/hub/exports/building_energy/insel/insel_monthly_energy_balance.py
index 6f831ac4..47e0bff9 100644
--- a/hub/exports/building_energy/insel/insel_monthly_energy_balance.py
+++ b/hub/exports/building_energy/insel/insel_monthly_energy_balance.py
@@ -117,7 +117,9 @@ class InselMonthlyEnergyBalance(Insel):
 
     for thermal_boundary in thermal_zone.thermal_boundaries:
       type_code = _CONSTRUCTION_CODE[thermal_boundary.type]
-      window_area = thermal_boundary.opaque_area * thermal_boundary.window_ratio / (1 - thermal_boundary.window_ratio)
+      window_area = 0
+      if thermal_boundary.window_ratio < 1:
+        window_area = thermal_boundary.opaque_area * thermal_boundary.window_ratio / (1 - thermal_boundary.window_ratio)
 
       parameters.append(type_code)
       if thermal_boundary.type != cte.GROUND:
diff --git a/hub/helpers/geometry_helper.py b/hub/helpers/geometry_helper.py
index 0327f97b..d650eefd 100644
--- a/hub/helpers/geometry_helper.py
+++ b/hub/helpers/geometry_helper.py
@@ -49,6 +49,7 @@ class GeometryHelper:
   """
   Geometry helper class
   """
+  # todo: complete dictionary
   srs_transformations = {
     'urn:adv:crs:ETRS89_UTM32*DE_DHHN92_NH': 'epsg:25832'
   }
@@ -63,15 +64,25 @@ class GeometryHelper:
 
   @staticmethod
   def city_mapping(city, building_names=None, plot=False):
+    """
+    Returns a shared_information dictionary like
+
+    {
+     "building_name" : [{line: 0 coordinate_1: [x,y,z], coordinate_2:[x, y, z], points: 0}]
+    }
+    """
+    shared_information = {}
     if building_names is None:
       building_names = [b.name for b in city.buildings]
     x = int((city.upper_corner[0] - city.lower_corner[0]) * 0.5) + 1
     y = int((city.upper_corner[1] - city.lower_corner[1]) * 0.5) + 1
-    city_map = [['' for _ in range(y + 1)] for _ in range(x + 1)]
+    city_map = [[{} for _ in range(y + 1)] for _ in range(x + 1)]
     img = Image.new('RGB', (x + 1, y + 1), "black")  # create a new black image
     city_image = img.load()  # create the pixel map
     for building_name in building_names:
       building = city.city_object(building_name)
+      shared_information[building_name]: []
+      line = 0
       for ground in building.grounds:
         length = len(ground.perimeter_polygon.coordinates) - 1
         for i, coordinate in enumerate(ground.perimeter_polygon.coordinates):
@@ -79,6 +90,8 @@ class GeometryHelper:
           if i == length:
             j = 0
           next_coordinate = ground.perimeter_polygon.coordinates[j]
+          line_dictionary = {"line": line, "coordinate_1": coordinate, "coordinate_2":next_coordinate, "points": 0}
+          print(line_dictionary)
           point = GeometryHelper.coordinate_to_map_point(coordinate, city)
           distance = GeometryHelper.distance_between_points(coordinate, next_coordinate)
           if distance == 0:
@@ -101,6 +114,7 @@ class GeometryHelper:
                 neighbour.neighbours = [building]
               elif building not in neighbour.neighbours:
                 neighbour.neighbours.append(building)
+          line += 1
     if plot:
       img.show()
 
diff --git a/hub/imports/construction/nrcan_physics_parameters.py b/hub/imports/construction/nrcan_physics_parameters.py
index eb499080..4ceb4e57 100644
--- a/hub/imports/construction/nrcan_physics_parameters.py
+++ b/hub/imports/construction/nrcan_physics_parameters.py
@@ -51,7 +51,7 @@ class NrcanPhysicsParameters:
             for thermal_zone in internal_zone.thermal_zones:
               thermal_zone.total_floor_area = thermal_zone.footprint_area
         else:
-          number_of_storeys = int(float(building.eave_height) / float(building.average_storey_height))
+          number_of_storeys = int(building.eave_height / building.average_storey_height)
           thermal_zone = building.internal_zones[0].thermal_zones[0]
           thermal_zone.total_floor_area = thermal_zone.footprint_area * number_of_storeys
       else:
@@ -69,7 +69,7 @@ class NrcanPhysicsParameters:
     nrcan_archetypes = nrcan_catalog.entries('archetypes')
     for building_archetype in nrcan_archetypes:
       construction_period_limits = building_archetype.construction_period.split('_')
-      if int(construction_period_limits[0]) <= int(year_of_construction) < int(construction_period_limits[1]):
+      if int(construction_period_limits[0]) <= year_of_construction < int(construction_period_limits[1]):
         if (str(function) == str(building_archetype.function)) and \
            (climate_zone == str(building_archetype.climate_zone)):
           return building_archetype
@@ -135,12 +135,12 @@ class NrcanPhysicsParameters:
         # The agreement is that the layers are defined from outside to inside
         external_layer = construction_archetype.layers[0]
         external_surface = thermal_boundary.parent_surface
-        external_surface.short_wave_reflectance = 1 - float(external_layer.material.solar_absorptance)
-        external_surface.long_wave_emittance = 1 - float(external_layer.material.solar_absorptance)
+        external_surface.short_wave_reflectance = 1 - external_layer.material.solar_absorptance
+        external_surface.long_wave_emittance = 1 - external_layer.material.solar_absorptance
         internal_layer = construction_archetype.layers[len(construction_archetype.layers) - 1]
         internal_surface = thermal_boundary.internal_surface
-        internal_surface.short_wave_reflectance = 1 - float(internal_layer.material.solar_absorptance)
-        internal_surface.long_wave_emittance = 1 - float(internal_layer.material.solar_absorptance)
+        internal_surface.short_wave_reflectance = 1 - internal_layer.material.solar_absorptance
+        internal_surface.long_wave_emittance = 1 - internal_layer.material.solar_absorptance
 
         for thermal_opening in thermal_boundary.thermal_openings:
           if construction_archetype.window is not None:
diff --git a/hub/imports/construction/nrel_physics_parameters.py b/hub/imports/construction/nrel_physics_parameters.py
index 6de4771a..e1e3fa06 100644
--- a/hub/imports/construction/nrel_physics_parameters.py
+++ b/hub/imports/construction/nrel_physics_parameters.py
@@ -58,7 +58,7 @@ class NrelPhysicsParameters:
             for thermal_zone in internal_zone.thermal_zones:
               thermal_zone.total_floor_area = thermal_zone.footprint_area
         else:
-          number_of_storeys = int(float(building.eave_height) / float(building.average_storey_height))
+          number_of_storeys = int(building.eave_height / building.average_storey_height)
           thermal_zone = building.internal_zones[0].thermal_zones[0]
           thermal_zone.total_floor_area = thermal_zone.footprint_area * number_of_storeys
       else:
@@ -78,7 +78,7 @@ class NrelPhysicsParameters:
       construction_period_limits = building_archetype.construction_period.split(' - ')
       if construction_period_limits[1] == 'PRESENT':
         construction_period_limits[1] = 3000
-      if int(construction_period_limits[0]) <= int(year_of_construction) < int(construction_period_limits[1]):
+      if int(construction_period_limits[0]) <= year_of_constructionF < int(construction_period_limits[1]):
         if (str(function) == str(building_archetype.function)) and \
            (climate_zone == str(building_archetype.climate_zone)):
           return building_archetype
@@ -130,12 +130,12 @@ class NrelPhysicsParameters:
         # The agreement is that the layers are defined from outside to inside
         external_layer = construction_archetype.layers[0]
         external_surface = thermal_boundary.parent_surface
-        external_surface.short_wave_reflectance = 1 - float(external_layer.material.solar_absorptance)
-        external_surface.long_wave_emittance = 1 - float(external_layer.material.solar_absorptance)
+        external_surface.short_wave_reflectance = 1 - external_layer.material.solar_absorptance
+        external_surface.long_wave_emittance = 1 - external_layer.material.solar_absorptance
         internal_layer = construction_archetype.layers[len(construction_archetype.layers) - 1]
         internal_surface = thermal_boundary.internal_surface
-        internal_surface.short_wave_reflectance = 1 - float(internal_layer.material.solar_absorptance)
-        internal_surface.long_wave_emittance = 1 - float(internal_layer.material.solar_absorptance)
+        internal_surface.short_wave_reflectance = 1 - internal_layer.material.solar_absorptance
+        internal_surface.long_wave_emittance = 1 - internal_layer.material.solar_absorptance
 
         for thermal_opening in thermal_boundary.thermal_openings:
           if construction_archetype.window is not None:
diff --git a/hub/imports/geometry/rhino.py b/hub/imports/geometry/rhino.py
index dab5cd2e..c4bf354d 100644
--- a/hub/imports/geometry/rhino.py
+++ b/hub/imports/geometry/rhino.py
@@ -124,7 +124,7 @@ class Rhino:
           # todo: this is a hack for dompark project it should not be done this way windows should be correctly modeled
           # if the distance between the wall plane and the window is less than 2m
           # and the window Z coordinate it's between the wall Z, it's a window of that wall
-          if plane.distance(corner) <= 2:
+          if plane.distance_to_point(corner) <= 2:
             # check if the window is in the right high.
             if surface.upper_corner[2] >= corner[2] >= surface.lower_corner[2]:
               if surface.holes_polygons is None:
diff --git a/hub/imports/usage/comnet_usage_parameters.py b/hub/imports/usage/comnet_usage_parameters.py
index 7c6c137e..6dcab450 100644
--- a/hub/imports/usage/comnet_usage_parameters.py
+++ b/hub/imports/usage/comnet_usage_parameters.py
@@ -189,10 +189,15 @@ class ComnetUsageParameters:
         _schedule_values[v, day] += value * archetype.appliances.density
         _sum += value * archetype.appliances.density * _number_of_days_per_type[day]
 
-    _latent_fraction = _latent_heat_gain / _total_heat_gain
-    _radiative_fraction = _radiative_heat_gain / _total_heat_gain
-    _convective_fraction = _convective_heat_gain / _total_heat_gain
-    _average_internal_gain = _sum / _total_heat_gain
+    _latent_fraction = 0
+    _radiative_fraction = 0
+    _convective_fraction = 0
+    _average_internal_gain = 0
+    if _total_heat_gain != 0:
+      _latent_fraction = _latent_heat_gain / _total_heat_gain
+      _radiative_fraction = _radiative_heat_gain / _total_heat_gain
+      _convective_fraction = _convective_heat_gain / _total_heat_gain
+      _average_internal_gain = _sum / _total_heat_gain
 
     _schedules = []
     for day in range(0, len(_DAYS)):