diff --git a/ifc_observer.py b/ifc_observer.py
index 31ea792..43332c2 100644
--- a/ifc_observer.py
+++ b/ifc_observer.py
@@ -139,17 +139,18 @@ def save(self):
             return
         doc = FreeCAD.getDocument(self.docname)
         del self.docname
-        objs = []
+        projects = []
         if hasattr(doc, "IfcFilePath") and hasattr(doc, "Modified"):
             if doc.Modified:
-                objs.append(doc)
+                projects.append(doc)
         else:
             for obj in doc.findObjects(Type="Part::FeaturePython"):
                 if hasattr(obj, "IfcFilePath") and hasattr(obj, "Modified"):
                     if obj.Modified:
-                        objs.append(obj)
-        if objs:
+                        projects.append(obj)
+        if projects:
             import ifc_tools  # lazy loading
+            import ifc_viewproviders
 
             ask = params.GetBool("AskBeforeSaving", True)
             if ask and FreeCAD.GuiUp:
@@ -164,11 +165,13 @@ def save(self):
                 ask = dlg.checkAskBeforeSaving.isChecked()
                 params.SetBool("AskBeforeSaving", ask)
 
-            for obj in objs:
-                if obj.IfcFilePath and getattr(obj.Proxy, "ifcfile", None):
-                    obj.ViewObject.Proxy.save()
-                else:
-                    obj.ViewObject.Proxy.save_as()
+            for project in projects:
+                if getattr(project.Proxy, "ifcfile", None):
+                    if project.IfcFilePath:
+                        ifc_tools.save(project)
+                    else:
+                        ifc_viewproviders.get_filepath(project)
+                        ifc_tools.save(project)
 
     def convert(self):
         """Converts an object to IFC"""
diff --git a/ifc_status.py b/ifc_status.py
index 083becd..1b59d13 100644
--- a/ifc_status.py
+++ b/ifc_status.py
@@ -108,6 +108,7 @@ def unlock_document():
         props += [p for p in doc.PropertiesList if doc.getGroupOfProperty(p) == "IFC"]
         for prop in props:
             doc.removeProperty(prop)
+        project.Modified = True
         doc.commitTransaction()
         doc.recompute()
 
@@ -153,6 +154,7 @@ def lock_document():
                 # 1a all objects are already inside a project
                 pass
             doc.removeObject(project.Name)
+            doc.Modified = True
             doc.commitTransaction()
             doc.recompute()
         elif len(projects) > 1:
@@ -165,10 +167,12 @@ def lock_document():
             ifc_tools.convert_document(doc, silent=True)
             ifcfile = doc.Proxy.ifcfile
             objs = find_toplevel(doc.Objects)
-            exportIFC.export(objs, ifcfile)
+            prefs, context = ifc_tools.get_export_preferences(ifcfile)
+            exportIFC.export(objs, ifcfile, preferences=prefs)
             for n in [o.Name for o in doc.Objects]:
                 doc.removeObject(n)
             ifc_tools.create_children(doc, ifcfile, recursive=True)
+            doc.Modified = True
             doc.commitTransaction()
             doc.recompute()
         else:
diff --git a/ifc_tools.py b/ifc_tools.py
index 1124463..787d68d 100644
--- a/ifc_tools.py
+++ b/ifc_tools.py
@@ -167,6 +167,7 @@ def setup_project(proj, filename, shapemode, silent):
     project = ifcfile.by_type("IfcProject")[0]
     # TODO configure version history
     # https://blenderbim.org/docs-python/autoapi/ifcopenshell/api/owner/create_owner_history/index.html
+    # In IFC4, history is optional. What should we do here?
     proj.Proxy.ifcfile = ifcfile
     add_properties(proj, ifcfile, project, shapemode=shapemode)
     if not "Schema" in proj.PropertiesList:
@@ -1030,8 +1031,8 @@ def get_export_preferences(ifcfile):
     # the above lines yields meter -> file unit scale factor. We need mm
     prefs["SCALE_FACTOR"] = 0.001 / s
     context = ifcfile[
-        get_body_context_ids(ifcfile)[-1]
-    ]  # TODO should this be different?
+        get_body_context_ids(ifcfile)[0]
+    ]  # we take the first one (first found subcontext)
     return prefs, context
 
 
diff --git a/ifc_viewproviders.py b/ifc_viewproviders.py
index 274c8a4..c86ddac 100644
--- a/ifc_viewproviders.py
+++ b/ifc_viewproviders.py
@@ -417,29 +417,18 @@ def save(self):
 
         import ifc_tools  # lazy import
 
-        ifc_tools.save_ifc(self.Object)
-        self.Object.Modified = False
+        ifc_tools.save(self.Object)
         self.Object.Document.recompute()
 
     def saveas(self):
         """Saves the associated IFC file to another file"""
 
         import ifc_tools  # lazy import
-        from PySide import QtCore, QtGui  # lazy import
 
-        sf = QtGui.QFileDialog.getSaveFileName(
-            None,
-            "Save an IFC file",
-            self.Object.IfcFilePath,
-            "Industry Foundation Classes (*.ifc)",
-        )
-        if sf and sf[0]:
-            sf = sf[0]
-            if not sf.lower().endswith(".ifc"):
-                sf += ".ifc"
-            ifc_tools.save_ifc(self.Object, sf)
-            self.replace_file(self.Object, sf)
-            self.Object.Document.recompute()
+        get_filepath(self.Object)
+        ifc_tools.save(self.Object)
+        self.replace_file(self.Object, sf)
+        self.Object.Document.recompute()
 
     def replace_file(self, obj, newfile):
         """Asks the user if the attached file path needs to be replaced"""
@@ -626,3 +615,22 @@ def overlay(icon1, icon2):
     b.open(QtCore.QIODevice.WriteOnly)
     baseicon.save(b, "XPM")
     return ba.data().decode("latin1")
+
+
+def get_filepath(project):
+    """Saves the associated IFC file to another file"""
+
+    import ifc_tools  # lazy import
+    from PySide import QtCore, QtGui  # lazy import
+
+    sf = QtGui.QFileDialog.getSaveFileName(
+        None,
+        "Save an IFC file",
+        project.IfcFilePath,
+        "Industry Foundation Classes (*.ifc)",
+    )
+    if sf and sf[0]:
+        sf = sf[0]
+        if not sf.lower().endswith(".ifc"):
+            sf += ".ifc"
+        project.IfcFilePath = sf