added thermal_zones to the building

hub/city_model_structure/building.py

@@ -14,6 +14,7 @@ import hub.helpers.constants as cte
 from hub.city_model_structure.attributes.polyhedron import Polyhedron
 from hub.city_model_structure.building_demand.household import Household
 from hub.city_model_structure.building_demand.internal_zone import InternalZone
+from hub.city_model_structure.building_demand.thermal_zone import ThermalZone
 from hub.city_model_structure.building_demand.surface import Surface
 from hub.city_model_structure.city_object import CityObject
 from hub.city_model_structure.energy_systems.energy_system import EnergySystem
@@ -40,6 +41,7 @@ class Building(CityObject):
     self._floor_area = None
     self._roof_type = None
     self._internal_zones = None
+    self._thermal_zones = None
     self._shell = None
     self._aliases = []
     self._type = 'building'
@@ -115,6 +117,24 @@ class Building(CityObject):
       self._internal_zones = [InternalZone(self.surfaces, self.floor_area)]
     return self._internal_zones
 
+  @property
+  def thermal_zones(self) -> Union[None, List[ThermalZone]]:
+    """
+    Get building thermal zones
+    For Lod up to 3, there can be more than one thermal zone per internal zone.
+    In LoD 4, there can be more than one internal zone, and therefore, only one thermal zone per internal zone
+    :return: [ThermalZone]
+    """
+    if self._thermal_zones is None:
+      self._thermal_zones = []
+      for internal_zone in self.internal_zones:
+        if internal_zone.thermal_zones is None:
+          self._thermal_zones = None
+          return self._thermal_zones
+        for thermal_zone in internal_zone.thermal_zones:
+          self._thermal_zones.append(thermal_zone)
+    return self._thermal_zones
+
   @property
   def grounds(self) -> List[Surface]:
     """