diff --git a/src/Mod/BIM/Arch.py b/src/Mod/BIM/Arch.py
index 577ce7ef2b..bc9b98358d 100644
--- a/src/Mod/BIM/Arch.py
+++ b/src/Mod/BIM/Arch.py
@@ -1703,6 +1703,7 @@ def makeWindow(baseobj=None, width=None, height=None, parts=None, name=None):
     1. If baseobj is not a closed shape, the tool may not create a proper solid figure.
     """
     import Draft
+    import DraftGeomUtils
     from draftutils import todo
 
     if baseobj and Draft.getType(baseobj) == "Window" and FreeCAD.ActiveDocument:
@@ -1730,8 +1731,12 @@ def makeWindow(baseobj=None, width=None, height=None, parts=None, name=None):
         window.WindowParts = parts
     else:
         if baseobj:
-            if baseobj.getLinkedObject().isDerivedFrom("Part::Part2DObject"):
-                # Base object is a 2D object (sketch or wire)
+            linked_obj = baseobj.getLinkedObject(True)
+            if (linked_obj.isDerivedFrom("Part::Part2DObject")
+                or Draft.getType(linked_obj) in ["BezCurve", "BSpline", "Wire"]) \
+                    and DraftGeomUtils.isPlanar(baseobj.Shape):
+                # "BezCurve", "BSpline" and "Wire" objects created with < v1.1 are "Part::Part2DObject" objects.
+                # In all versions these objects need not be planar.
                 if baseobj.Shape.Wires:
                     part_type = "Frame"
                     if len(baseobj.Shape.Wires) == 1:
diff --git a/src/Mod/BIM/ArchCommands.py b/src/Mod/BIM/ArchCommands.py
index a446f7b722..8db79ecd2b 100644
--- a/src/Mod/BIM/ArchCommands.py
+++ b/src/Mod/BIM/ArchCommands.py
@@ -768,11 +768,14 @@ def pruneIncluded(objectslist,strict=False,silent=False):
                 for parent in obj.InList:
                     if not parent.isDerivedFrom("Part::Feature"):
                         pass
-                    elif Draft.getType(parent) in ["Space","Facebinder","Window","Roof","Clone","Site","Project"]:
-                        pass
                     elif parent.isDerivedFrom("Part::Part2DObject"):
                         # don't consider 2D objects based on arch elements
                         pass
+                    elif Draft.getType(parent) in [
+                            "BezCurve", "BSpline", "Clone", "Facebinder", "Wire",
+                            "Project", "Roof", "Site", "Space", "Window"
+                        ]:
+                        pass
                     elif parent.isDerivedFrom("PartDesign::FeatureBase"):
                         # don't consider a PartDesign_Clone that references obj
                         pass
diff --git a/src/Mod/BIM/ArchSectionPlane.py b/src/Mod/BIM/ArchSectionPlane.py
index 8d77f04bbd..bc2526d8ab 100644
--- a/src/Mod/BIM/ArchSectionPlane.py
+++ b/src/Mod/BIM/ArchSectionPlane.py
@@ -577,7 +577,16 @@ def getDXF(obj):
         return result
     if not allOn:
             objs = Draft.removeHidden(objs)
-    objs = [o for o in objs if ((not(Draft.getType(o) in ["Space","Dimension","Annotation"])) and (not (o.isDerivedFrom("Part::Part2DObject"))))]
+    objs = [
+        obj
+        for obj in objs
+        if (
+            not obj.isDerivedFrom("Part::Part2DObject")
+            and Draft.getType(obj) not in [
+                "BezCurve", "BSpline", "Wire", "Annotation", "Dimension", "Space"
+            ]
+        )
+    ]
     vshapes,hshapes,sshapes,cutface,cutvolume,invcutvolume = getCutShapes(objs,cutplane,onlySolids,clip,False,showHidden)
     if vshapes:
         result.append(TechDraw.projectToDXF(Part.makeCompound(vshapes),direction))
diff --git a/src/Mod/BIM/bimcommands/BimPreflight.py b/src/Mod/BIM/bimcommands/BimPreflight.py
index 734d6a80aa..5f29d28b3a 100644
--- a/src/Mod/BIM/bimcommands/BimPreflight.py
+++ b/src/Mod/BIM/bimcommands/BimPreflight.py
@@ -256,28 +256,20 @@ class BIM_Preflight_TaskPanel:
             objs = FreeCADGui.Selection.getSelection()
         # clean objects list of unwanted types
         objs = Draft.get_group_contents(objs, walls=True, addgroups=True)
-        objs = [obj for obj in objs if not obj.isDerivedFrom("Part::Part2DObject")]
-        objs = [obj for obj in objs if not obj.isDerivedFrom("App::Annotation")]
         objs = [
             obj
             for obj in objs
             if (
-                hasattr(obj, "Shape")
+                not obj.isDerivedFrom("App::DocumentObjectGroup")
+                and not obj.isDerivedFrom("App::Annotation")
+                and not obj.isDerivedFrom("Part::Part2DObject")
+                and Draft.getType(obj) not in ["BezCurve", "BSpline", "Wire", "WorkingPlaneProxy"]
+                and hasattr(obj, "Shape")
                 and obj.Shape
                 and not (obj.Shape.Edges and (not obj.Shape.Faces))
             )
         ]
-        objs = Arch.pruneIncluded(objs)
-        objs = [
-            obj for obj in objs if not obj.isDerivedFrom("App::DocumentObjectGroup")
-        ]
-        objs = [
-            obj
-            for obj in objs
-            if Draft.getType(obj)
-            not in ["DraftText", "Material", "MaterialContainer", "WorkingPlaneProxy"]
-        ]
-        return objs
+        return Arch.pruneIncluded(objs)
 
     def getToolTip(self, test):
         "gets the toolTip text from the ui file"
diff --git a/src/Mod/BIM/importers/exportIFC.py b/src/Mod/BIM/importers/exportIFC.py
index a12fbda457..43740f8805 100644
--- a/src/Mod/BIM/importers/exportIFC.py
+++ b/src/Mod/BIM/importers/exportIFC.py
@@ -282,9 +282,12 @@ def export(exportList, filename, colors=None, preferences=None):
     annotations = []
     specials = []
     for obj in objectslist:
-        if obj.isDerivedFrom("Part::Part2DObject"):
-            annotations.append(obj)
-        elif obj.isDerivedFrom("App::Annotation") or (Draft.getType(obj) in ["DraftText","Text","Dimension","LinearDimension","AngularDimension"]):
+        if obj.isDerivedFrom("Part::Part2DObject") \
+                or obj.isDerivedFrom("App::Annotation") \
+                or Draft.getType(obj) in [
+                        "BezCurve", "BSpline", "Wire",
+                        "DraftText", "Text", "Dimension", "LinearDimension", "AngularDimension"
+                    ]:
             annotations.append(obj)
         elif hasattr(obj, "Proxy") and hasattr(obj.Proxy, "export_ifc"):
             specials.append(obj)
diff --git a/src/Mod/BIM/nativeifc/ifc_export.py b/src/Mod/BIM/nativeifc/ifc_export.py
index 211f56ff79..ec9288de75 100644
--- a/src/Mod/BIM/nativeifc/ifc_export.py
+++ b/src/Mod/BIM/nativeifc/ifc_export.py
@@ -215,7 +215,10 @@ def is_annotation(obj):
         return True
     elif obj.isDerivedFrom("App::Annotation"):
         return True
-    elif Draft.getType(obj) in ["DraftText",
+    elif Draft.getType(obj) in ["BezCurve",
+                                "BSpline",
+                                "Wire",
+                                "DraftText",
                                 "Text",
                                 "Dimension",
                                 "LinearDimension",
diff --git a/src/Mod/Draft/draftfunctions/fuse.py b/src/Mod/Draft/draftfunctions/fuse.py
index 899aa3880d..152baaf6b8 100644
--- a/src/Mod/Draft/draftfunctions/fuse.py
+++ b/src/Mod/Draft/draftfunctions/fuse.py
@@ -57,7 +57,7 @@ def fuse(object1, object2):
         if len(f.Wires) > 1:
             holes = True
     if DraftGeomUtils.isCoplanar(object1.Shape.fuse(object2.Shape).Faces) and not holes:
-        obj = App.ActiveDocument.addObject("Part::Part2DObjectPython","Fusion")
+        obj = App.ActiveDocument.addObject("Part::FeaturePython", "Fusion")
         Wire(obj)
         if App.GuiUp:
             ViewProviderWire(obj.ViewObject)
@@ -65,10 +65,10 @@ def fuse(object1, object2):
         obj.Tool = object2
     elif holes:
         # temporary hack, since Part::Fuse objects don't remove splitters
-        obj = App.ActiveDocument.addObject("Part::Feature","Fusion")
+        obj = App.ActiveDocument.addObject("Part::Feature", "Fusion")
         obj.Shape = fshape
     else:
-        obj = App.ActiveDocument.addObject("Part::Fuse","Fusion")
+        obj = App.ActiveDocument.addObject("Part::Fuse", "Fusion")
         obj.Base = object1
         obj.Tool = object2
     if App.GuiUp:
diff --git a/src/Mod/Draft/draftfunctions/upgrade.py b/src/Mod/Draft/draftfunctions/upgrade.py
index 3c9ce544a8..132af193f8 100644
--- a/src/Mod/Draft/draftfunctions/upgrade.py
+++ b/src/Mod/Draft/draftfunctions/upgrade.py
@@ -563,7 +563,9 @@ def upgrade(objects, delete=False, force=None):
                     _msg(translate("draft", "Found object with several coplanar faces: refining them"))
 
             # only one object: if not parametric, we "draftify" it
-            elif len(objects) == 1 and not objects[0].isDerivedFrom("Part::Part2DObjectPython"):
+            elif len(objects) == 1 \
+                    and not objects[0].isDerivedFrom("Part::Part2DObjectPython") \
+                    and not utils.get_type(objects[0]) in ["BezCurve", "BSpline", "Wire"]:
                 result = _draftify(objects[0])
                 if result:
                     _msg(translate("draft", "Found 1 non-parametric object: draftifying it"))
@@ -603,7 +605,8 @@ def upgrade(objects, delete=False, force=None):
             # only one object: if not parametric, we "draftify" it
             elif len(objects) == 1 \
                     and len(edges) == 1 \
-                    and not objects[0].isDerivedFrom("Part::Part2DObjectPython"):
+                    and not objects[0].isDerivedFrom("Part::Part2DObjectPython") \
+                    and not utils.get_type(objects[0]) in ["BezCurve", "BSpline", "Wire"]:
                 edge_type = DraftGeomUtils.geomType(objects[0].Shape.Edges[0])
                 # currently only support Line and Circle
                 if edge_type in ("Line", "Circle"):
diff --git a/src/Mod/Draft/draftguitools/gui_subelements.py b/src/Mod/Draft/draftguitools/gui_subelements.py
index b84020637e..a3b933c23d 100644
--- a/src/Mod/Draft/draftguitools/gui_subelements.py
+++ b/src/Mod/Draft/draftguitools/gui_subelements.py
@@ -39,6 +39,7 @@ from PySide.QtCore import QT_TRANSLATE_NOOP
 import FreeCADGui as Gui
 from draftguitools import gui_base_original
 from draftguitools import gui_tool_utils
+from draftutils import utils
 from draftutils import gui_utils
 from draftutils.messages import _msg
 from draftutils.translate import translate
@@ -115,10 +116,12 @@ class SubelementHighlight(gui_base_original.Modifier):
     def get_editable_objects_from_selection(self):
         """Get editable Draft objects for the selection."""
         for obj in Gui.Selection.getSelection():
-            if obj.isDerivedFrom("Part::Part2DObject"):
+            if (obj.isDerivedFrom("Part::Part2DObject")
+                or utils.get_type(obj) in ["BezCurve", "BSpline", "Wire"]):
                 self.editable_objects.append(obj)
             elif (hasattr(obj, "Base")
-                  and obj.Base.isDerivedFrom("Part::Part2DObject")):
+                  and (obj.Base.isDerivedFrom("Part::Part2DObject")
+                       or utils.get_type(obj.Base) in ["BezCurve", "BSpline", "Wire"])):
                 self.editable_objects.append(obj.Base)
 
     def highlight_editable_objects(self):
diff --git a/src/Mod/Draft/draftmake/make_bezcurve.py b/src/Mod/Draft/draftmake/make_bezcurve.py
index b6cb58200b..9337104932 100644
--- a/src/Mod/Draft/draftmake/make_bezcurve.py
+++ b/src/Mod/Draft/draftmake/make_bezcurve.py
@@ -81,7 +81,8 @@ def make_bezcurve(pointslist,
         utils.type_check([(placement,App.Placement)], "make_bezcurve")
     if len(pointslist) == 2: fname = "Line"
     else: fname = "BezCurve"
-    obj = App.ActiveDocument.addObject("Part::Part2DObjectPython",fname)
+    obj = App.ActiveDocument.addObject("Part::FeaturePython", fname)
+    obj.addExtension("Part::AttachExtensionPython")
     BezCurve(obj)
     obj.Points = pointslist
     if degree:
diff --git a/src/Mod/Draft/draftmake/make_block.py b/src/Mod/Draft/draftmake/make_block.py
index 2ca91d1dd1..3d2e563a7a 100644
--- a/src/Mod/Draft/draftmake/make_block.py
+++ b/src/Mod/Draft/draftmake/make_block.py
@@ -50,7 +50,8 @@ def make_block(objectslist):
     if not App.ActiveDocument:
         App.Console.PrintError("No active document. Aborting\n")
         return
-    obj = App.ActiveDocument.addObject("Part::Part2DObjectPython","Block")
+    obj = App.ActiveDocument.addObject("Part::FeaturePython", "Block")
+    obj.addExtension("Part::AttachExtensionPython")
     Block(obj)
     obj.Components = objectslist
     if App.GuiUp:
diff --git a/src/Mod/Draft/draftmake/make_bspline.py b/src/Mod/Draft/draftmake/make_bspline.py
index d5c6b4e4fa..fba96813d2 100644
--- a/src/Mod/Draft/draftmake/make_bspline.py
+++ b/src/Mod/Draft/draftmake/make_bspline.py
@@ -92,7 +92,8 @@ def make_bspline(pointslist, closed=False, placement=None, face=None, support=No
         utils.type_check([(placement,App.Placement)], "make_bspline")
     if len(pointslist) == 2: fname = "Line"
     else: fname = "BSpline"
-    obj = App.ActiveDocument.addObject("Part::Part2DObjectPython",fname)
+    obj = App.ActiveDocument.addObject("Part::FeaturePython", fname)
+    obj.addExtension("Part::AttachExtensionPython")
     BSpline(obj)
     obj.Closed = closed
     obj.Points = pointslist
diff --git a/src/Mod/Draft/draftmake/make_clone.py b/src/Mod/Draft/draftmake/make_clone.py
index 8fe82ee1df..2c5bf5c9eb 100644
--- a/src/Mod/Draft/draftmake/make_clone.py
+++ b/src/Mod/Draft/draftmake/make_clone.py
@@ -67,10 +67,16 @@ def make_clone(obj, delta=None, forcedraft=False):
     if not isinstance(obj,list):
         obj = [obj]
 
-    if (len(obj) == 1) and obj[0].isDerivedFrom("Part::Part2DObject"):
-        cl = App.ActiveDocument.addObject("Part::Part2DObjectPython","Clone2D")
+    if len(obj) == 1 \
+            and obj[0].isDerivedFrom("Part::Part2DObject") \
+            and utils.get_type(obj[0]) not in ["BezCurve", "BSpline", "Wire"]:
+        # "BezCurve", "BSpline" and "Wire" objects created with < v1.1
+        # are "Part::Part2DObject" objects but they need not be 2D.
+        cl = App.ActiveDocument.addObject("Part::Part2DObjectPython", "Clone2D")
         cl.Label = prefix + obj[0].Label + " (2D)"
-    elif (len(obj) == 1) and (hasattr(obj[0],"CloneOf") or (utils.get_type(obj[0]) == "BuildingPart")) and (not forcedraft):
+    elif len(obj) == 1 \
+            and (hasattr(obj[0], "CloneOf") or utils.get_type(obj[0]) == "BuildingPart") \
+            and not forcedraft:
         # arch objects can be clones
         try:
             import Arch
@@ -106,7 +112,7 @@ def make_clone(obj, delta=None, forcedraft=False):
 
     # fall back to Draft clone mode
     if not cl:
-        cl = App.ActiveDocument.addObject("Part::FeaturePython","Clone")
+        cl = App.ActiveDocument.addObject("Part::FeaturePython", "Clone")
         cl.addExtension("Part::AttachExtensionPython")
         cl.Label = prefix + obj[0].Label
     Clone(cl)
diff --git a/src/Mod/Draft/draftmake/make_wire.py b/src/Mod/Draft/draftmake/make_wire.py
index bd82bdf04f..d650e431d4 100644
--- a/src/Mod/Draft/draftmake/make_wire.py
+++ b/src/Mod/Draft/draftmake/make_wire.py
@@ -108,7 +108,8 @@ def make_wire(pointslist, closed=False, placement=None, face=None, support=None,
     else:
         fname = "Wire"
 
-    obj = App.ActiveDocument.addObject("Part::Part2DObjectPython", fname)
+    obj = App.ActiveDocument.addObject("Part::FeaturePython", fname)
+    obj.addExtension("Part::AttachExtensionPython")
     Wire(obj)
     obj.Points = pointslist
     obj.Closed = closed
diff --git a/src/Mod/Draft/draftobjects/base.py b/src/Mod/Draft/draftobjects/base.py
index ca3860987d..507a92fec1 100644
--- a/src/Mod/Draft/draftobjects/base.py
+++ b/src/Mod/Draft/draftobjects/base.py
@@ -66,9 +66,7 @@ class DraftObject(object):
         allows distinguishing among various types of objects
         derived from the same C++ class.
 
-            >>> print(A.TypeId, "->", A.Proxy.Type)
-            Part::Part2DObjectPython -> Wire
-            >>> print(B.TypeId, "->", B.Proxy.Type)
+            >>> print(obj.TypeId, "->", obj.Proxy.Type)
             Part::Part2DObjectPython -> Circle
 
     This class attribute is accessible through the `Proxy` object:
diff --git a/src/Mod/Draft/importAirfoilDAT.py b/src/Mod/Draft/importAirfoilDAT.py
index 9380975ff4..4ad1f0de17 100644
--- a/src/Mod/Draft/importAirfoilDAT.py
+++ b/src/Mod/Draft/importAirfoilDAT.py
@@ -121,8 +121,8 @@ def process(filename):
 
     Returns
     -------
-    Part::Part2DObject or None.
-        The created Draft Wire object or None if the file contains less
+    Part::Feature or None.
+        The created object or None if the file contains fewer
         than 3 points.
     """
     # Regex to identify data rows and throw away unused metadata
diff --git a/src/Mod/Draft/importDXF.py b/src/Mod/Draft/importDXF.py
index eb58ad9586..2f458b7ab6 100644
--- a/src/Mod/Draft/importDXF.py
+++ b/src/Mod/Draft/importDXF.py
@@ -795,7 +795,7 @@ def drawLine(line, forceShape=False):
 
     Returns
     -------
-    Part::Part2DObject or Part::TopoShape ('Edge')
+    Part::Feature or Part::TopoShape ('Edge')
         The returned object is normally a `Wire`, if the global
         variables `dxfCreateDraft` or `dxfCreateSketch` are set,
         and `forceShape` is `False`.
@@ -847,7 +847,7 @@ def drawPolyline(polyline, forceShape=False, num=None):
 
     Returns
     -------
-    Part::Part2DObject or Part::TopoShape ('Wire', 'Face', 'Shell')
+    Part::Feature or Part::TopoShape ('Wire', 'Face', 'Shell')
         It returns `None` if it fails producing a shape.
 
     If the polyline has a `width` and the global variable
@@ -1292,7 +1292,7 @@ def drawSplineIterpolation(verts, closed=False, forceShape=False,
 
     Returns
     -------
-    Part::Part2DObject or Part::TopoShape ('Edge', 'Face')
+    Part::Feature or Part::TopoShape ('Edge', 'Face')
         The returned object is normally a `Draft Wire` or `Draft BSpline`,
         if the global variables `dxfCreateDraft` or `dxfCreateSketch` are set,
         and `forceShape` is `False`.
@@ -1350,7 +1350,7 @@ def drawSplineOld(spline, forceShape=False):
 
     Returns
     -------
-    Part::Part2DObject or Part::TopoShape ('Edge', 'Face')
+    Part::Feature or Part::TopoShape ('Edge', 'Face')
         The returned object is normally a `Draft Wire` or `Draft BSpline`
         as returned from `drawSplineIterpolation()`.
 
@@ -1409,7 +1409,7 @@ def drawSpline(spline, forceShape=False):
 
     Returns
     -------
-    Part::Part2DObject or Part::TopoShape ('Edge', 'Face')
+    Part::Feature or Part::TopoShape ('Edge', 'Face')
         The returned object is normally a `Draft BezCurve`
         created with `Draft.make_bezcurve(controlpoints, degree=degree)`,
         if `forceShape` is `False` and there are no weights.
@@ -1813,7 +1813,7 @@ def drawLayerBlock(objlist, name="LayerBlock"):
 
     Returns
     -------
-    Part::Part2DObject or Part::TopoShape ('Compound')
+    Part::Feature or Part::TopoShape ('Compound')
         If the global variables `dxfCreateDraft` or `dxfCreateSketch` are set,
         and no element in `objlist` is a `Part.Shape`,
         it will try to return a `Draft Block`.
@@ -1910,9 +1910,8 @@ def addObject(shape, name="Shape", layer=None):
     -------
     Part::Feature or Part::Part2DObject
         If the `shape` is a simple `Part.Shape`, it will be encapsulated
-        inside a `Part::Feature` object and this will be returned.
-        Otherwise, it is assumed it is already a Draft object
-        (`Part::Part2DObject`) and will just return this.
+        inside a `Part::Feature` object and this will be returned. Otherwise,
+        it is assumed it is already a Draft object which will just be returned.
 
         It applies the text and line color by calling `formatObject()`
         before returning the new object.
@@ -1941,8 +1940,6 @@ def addObject(shape, name="Shape", layer=None):
                 l = layerObjects[lay]
             l.append(newob)
 
-
-
     formatObject(newob)
     return newob