diff --git a/topologie/models.py b/topologie/models.py
index 2eaa3364..954fa9c4 100644
--- a/topologie/models.py
+++ b/topologie/models.py
@@ -611,16 +611,19 @@ class Building(AclMixin, RevMixin, models.Model):
         """Returns all ap of the building"""
         return AccessPoint.all_ap_in(self)
 
-    @cached_property
-    def cached_name(self):
-        return self.__str__()
-
-    def __str__(self):
+    def get_name(self):
         if Dormitory.objects.count() > 1:
             return self.dormitory.name + " : " + self.name
         else:
             return self.name
 
+    @cached_property
+    def cached_name(self):
+        return self.get_name() 
+
+    def __str__(self):
+        return self.cached_name
+
 
 class Port(AclMixin, RevMixin, models.Model):
     """ Definition d'un port. Relié à un switch(foreign_key),
diff --git a/topologie/views.py b/topologie/views.py
index c8be33b7..9781a7d2 100644
--- a/topologie/views.py
+++ b/topologie/views.py
@@ -217,7 +217,7 @@ def index_port(request, switch, switchid):
 @can_view_all(Room)
 def index_room(request):
     """ Affichage de l'ensemble des chambres"""
-    room_list = Room.objects
+    room_list = Room.objects.select_related('building__dormitory')
     room_list = SortTable.sort(
         room_list,
         request.GET.get('col'),