diff --git a/hub/city_model_structure/building_demand/thermal_control.py b/hub/city_model_structure/building_demand/thermal_control.py
index ee3de07c..686a4e1d 100644
--- a/hub/city_model_structure/building_demand/thermal_control.py
+++ b/hub/city_model_structure/building_demand/thermal_control.py
@@ -4,6 +4,7 @@ SPDX - License - Identifier: LGPL - 3.0 - or -later
 Copyright © 2022 Concordia CERC group
 Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
+from math import inf
 from typing import Union, List
 from hub.city_model_structure.attributes.schedule import Schedule
 
@@ -22,16 +23,14 @@ class ThermalControl:
 
   @staticmethod
   def _maximum_value(schedules):
-    maximum = -1000
+    maximum = -inf
     for schedule in schedules:
-      for value in schedule.values:
-        if value > maximum:
-          maximum = value
+      maximum = max(maximum, max(schedule.values))
     return maximum
 
   @staticmethod
   def _minimum_value(schedules):
-    minimum = 1000
+    minimum = inf
     for schedule in schedules:
       minimum = min(minimum, min(schedule.values))
     return minimum