diff --git a/teaser/data/output/aixlib_output.py b/teaser/data/output/aixlib_output.py
index 0a7a4ad79..f1d434cc8 100644
--- a/teaser/data/output/aixlib_output.py
+++ b/teaser/data/output/aixlib_output.py
@@ -47,7 +47,7 @@ def export_aixlib(prj,
     assert corG in [None, True, False]
 
     uses = ['Modelica(version = "3.2.1")',
-            "AixLib(version=\"0.3.0\")"]
+            "AixLib(version=\"0.3.1\")"]
 
     # use the same zone templates for all exports
     zone_template = Template(
diff --git a/teaser/logic/simulation/aixlib.py b/teaser/logic/simulation/aixlib.py
index f4a295036..f4d26cea4 100644
--- a/teaser/logic/simulation/aixlib.py
+++ b/teaser/logic/simulation/aixlib.py
@@ -25,6 +25,9 @@ def compare_orientation(bldg):
     """
 
     orient_tilt_help = []
+    bldg.orient_tilt = []
+    bldg.orientation_bldg = []
+    bldg.tilt_bldg = []
 
     for zone in bldg.thermal_zones:
         for wall in zone.outer_walls:
diff --git a/teaser/logic/simulation/annex.py b/teaser/logic/simulation/annex.py
index 42070c4bb..f3c2c02ef 100644
--- a/teaser/logic/simulation/annex.py
+++ b/teaser/logic/simulation/annex.py
@@ -34,6 +34,9 @@ def compare_orientation(bldg, number_of_elements=3):
 
     orient_tilt_help1 = []
     orient_tilt_help2 = []
+    bldg.orientation_bldg = []
+    bldg.tilt_bldg = []
+
     for zone in bldg.thermal_zones:
         for wall in zone.outer_walls:
             if wall.orientation != -2:
diff --git a/teaser/project.py b/teaser/project.py
index f7af26e15..255f6d867 100644
--- a/teaser/project.py
+++ b/teaser/project.py
@@ -143,18 +143,14 @@ def calc_all_buildings(self,
         self._used_library_calc = used_library
         for bldg in reversed(self.buildings):
             try:
-                bldg.calc_building_parameter()
+                bldg.calc_building_parameter(
+                    number_of_elements=self._number_of_elements_calc,
+                    merge_windows=self._merge_windows_calc,
+                    used_library=self._used_library_calc)
             except:
                 print(bldg.name)
                 self.buildings.remove(bldg)
 
-        for bldg in self.buildings:
-
-            bldg.calc_building_parameter(
-                number_of_elements=self._number_of_elements_calc,
-                merge_windows=self._merge_windows_calc,
-                used_library=self._used_library_calc)
-
     def retrofit_all_buildings(self,
                                year_of_retrofit,
                                window_type=None,