diff --git a/city_model_structure/building.py b/city_model_structure/building.py
index ae14ad05..d99b8a9b 100644
--- a/city_model_structure/building.py
+++ b/city_model_structure/building.py
@@ -10,6 +10,7 @@ import numpy as np
 from matplotlib import pylab
 from shapely import ops
 from shapely.geometry import MultiPolygon
+import pandas as pd
 
 from city_model_structure.surface import Surface
 from city_model_structure.thermal_boundary import ThermalBoundary
@@ -38,8 +39,10 @@ class Building(CityObject):
     self._usage_zones = []
     self._building_units = []
     self._type = 'building'
-    self._monthly_heating = []
-    self._monthly_cooling = []
+    self._monthly_heating = pd.DataFrame()
+    self._monthly_cooling = pd.DataFrame()
+    self._hourly_heating = pd.DataFrame()
+    self._hourly_cooling = pd.DataFrame()
 
     # ToDo: Check this for LOD4
     self._thermal_zones = []
@@ -272,33 +275,65 @@ class Building(CityObject):
     self._building_units = value
 
   @property
-  def monthly_heating(self) -> [float]:
+  def monthly_heating(self) -> pd.DataFrame:
     """
     building monthly heating values in Watts-hour
-    :return: List of float (12 values)
+    :return: DataFrame with 12 values and a header with the source of those
     """
     return self._monthly_heating
 
   @monthly_heating.setter
   def monthly_heating(self, value):
     """
-    building monthly heating values in Watts-hour
-    :param value: [heating demand]
+    building monthly heating values in Watts-hour and a header with the source
+    :param value: DataFrame(heating demand)
     """
-    self._monthly_heating = value
+    self._monthly_heating.append(value)
 
   @property
-  def monthly_cooling(self) -> [float]:
+  def monthly_cooling(self) -> pd.DataFrame:
     """
     building monthly cooling values in Watts-hour
-    :return: List of float (12 values)
+    :return: DataFrame with 12 values and a header with the source of those
     """
     return self._monthly_cooling
 
   @monthly_cooling.setter
   def monthly_cooling(self, value):
     """
-    building monthly cooling values in Watts-hour
-    :param value: [heating demand]
+    building monthly cooling values in Watts-hour and a header with the source
+    :param value: DataFrame(cooling demand)
     """
-    self._monthly_cooling = value
+    self._monthly_cooling.append(value)
+
+  @property
+  def hourly_heating(self) -> pd.DataFrame:
+    """
+    building hourly heating values in Watts-hour
+    :return: DataFrame with 8760 values and a header with the source of those
+    """
+    return self._hourly_heating
+
+  @hourly_heating.setter
+  def hourly_heating(self, value):
+    """
+    building hourly heating values in Watts-hour and a header with the source
+    :param value: DataFrame(heating demand)
+    """
+    self._hourly_heating.append(value)
+
+  @property
+  def hourly_cooling(self) -> pd.DataFrame:
+    """
+    building hourly cooling values in Watts-hour
+    :return: DataFrame with 8760 values and a header with the source of those
+    """
+    return self._hourly_cooling
+
+  @hourly_cooling.setter
+  def hourly_cooling(self, value):
+    """
+    building hourly cooling values in Watts-hour and a header with the source
+    :param value: DataFrame(cooling demand)
+    """
+    self._hourly_cooling.append(value)