diff --git a/scripts/ep_workflow.py b/scripts/ep_workflow.py
index 41996aac..4f103af9 100644
--- a/scripts/ep_workflow.py
+++ b/scripts/ep_workflow.py
@@ -1,3 +1,5 @@
+import glob
+import os
 import sys
 from pathlib import Path
 import csv
@@ -21,6 +23,11 @@ try:
     value = argument[1]
     if option == '-g':
       gml = value
+  out_path = (Path(__file__).parent.parent / 'out_files')
+  files = glob.glob(f'{out_path}/*')
+  for file in files:
+    if file != '.gitignore':
+      os.remove(file)
 
   print('[simulation start]')
   city = GeometryFactory('citygml', gml).city
@@ -45,7 +52,7 @@ try:
       area += ground.perimeter_polygon.area
 
   print('exporting:')
-  out_path = (Path(__file__).parent.parent / 'out_files')
+
   ExportsFactory('obj', city, out_path).export()
   print('    geometry exported...')
   # todo: _idf exporter does not catch errors in exporting