diff --git a/src/Mod/BIM/ArchWindow.py b/src/Mod/BIM/ArchWindow.py
index 42d68f642f..54af545600 100644
--- a/src/Mod/BIM/ArchWindow.py
+++ b/src/Mod/BIM/ArchWindow.py
@@ -188,6 +188,13 @@ class _Window(ArchComponent.Component):
         # Add features in the SketchArch External Add-on
         self.addSketchArchFeatures(obj, mode='ODR')
 
+        # Need to restore 'initial' settings as corresponding codes in onChanged() does upon object creation
+        self.baseSill = obj.Sill.Value
+        self.basePos = obj.Base.Placement.Base
+        self.atthOff = None
+        if hasattr(obj, 'AttachmentOffsetXyzAndRotation'):
+            self.atthOff = obj.AttachmentOffsetXyzAndRotation.Base
+
     def onBeforeChange(self,obj,prop):
 
         if prop in ["Base","WindowParts","Placement","HoleDepth","Height","Width","Hosts"]:
@@ -200,12 +207,36 @@ class _Window(ArchComponent.Component):
         self.hideSubobjects(obj,prop)
         if prop == "Sill":
             val = getattr(obj,prop).Value
-            if getattr(self, 'baseSill', None) is None and getattr(self, 'basePos', None) is None:
+
+            if (getattr(self, 'baseSill', None) is None and
+                getattr(self, 'basePos', None) is None and
+                getattr(self, 'atthOff', None) is None):  # TODO Any cases only 1 or 2 are not None?
                 self.baseSill = val
                 self.basePos = obj.Base.Placement.Base
+                self.atthOff = None
+                if hasattr(obj, 'AttachmentOffsetXyzAndRotation'):
+                    self.atthOff = obj.AttachmentOffsetXyzAndRotation.Base
                 return
 
-            obj.Base.Placement.Base.z = self.basePos.z + (obj.Sill.Value - self.baseSill)
+            import ArchSketchObject  # Need to import per method
+            host = None
+            if obj.Hosts:
+                host = obj.Hosts[0]
+            if (hasattr(obj, 'AttachToAxisOrSketch') and
+                obj.AttachToAxisOrSketch == "Host" and
+                host and Draft.getType(host.Base) == "ArchSketch" and
+                hasattr(ArchSketchObject, 'updateAttachmentOffset')):
+                SketchArch = True
+            else:
+                SketchArch = False
+
+            if SketchArch:
+                objAttOff = obj.AttachmentOffsetXyzAndRotation
+                objAttOff.Base.z = self.atthOff.z + (obj.Sill.Value - self.baseSill)
+                obj.AttachmentOffsetXyzAndRotation = objAttOff
+            else:
+                obj.Base.Placement.Base.z = self.basePos.z + (obj.Sill.Value - self.baseSill)
+
         elif not "Restore" in obj.State:
             if prop in ["Base","WindowParts","Placement","HoleDepth","Height","Width","Hosts","Shape"]:
                 # anti-recursive loops, bc the base sketch will touch the Placement all the time
diff --git a/src/Mod/BIM/bimcommands/BimWindow.py b/src/Mod/BIM/bimcommands/BimWindow.py
index 451d97b566..05ab3d0e00 100644
--- a/src/Mod/BIM/bimcommands/BimWindow.py
+++ b/src/Mod/BIM/bimcommands/BimWindow.py
@@ -210,7 +210,6 @@ class Arch_Window:
                         break
                     FreeCADGui.doCommand("win = FreeCAD.ActiveDocument.getObject('" + o.Name + "')")
                     FreeCADGui.doCommand("win.Base.Placement = pl")
-                    # 2025.5.25
                     # Historically, this normal was deduced by the orientation of the Base Sketch and hardcoded in the Normal property.
                     # Now with the new AutoNormalReversed property/flag, set True as default, the auto Normal previously in opposite direction to is now consistent with that previously hardcoded.
                     # With the normal set to 'auto', window object would not suffer weird shape if the Base Sketch is rotated by some reason.
@@ -240,7 +239,11 @@ class Arch_Window:
                 FreeCAD.ArchSketchLock):
                 if self.Include:
                     # Window base sketch's placement stay at orgin is good if addon exists and self.Include
-                    FreeCADGui.doCommand("win = Arch.makeWindowPreset('" + WindowPresets[self.Preset] + "' " + wp + ", window_sill=" + str(self.Sill.Value) + ")")
+                    # Window object triggers onChanged() upon setting/changing Window.Sill to move Window's z position
+                    # For Window with SketchArch add-on, attachToHost() is to be run below below to set the 'initial' Window's placement first before triggering onChanged() below,
+                    # so window_sill parameter is not used here at the moment, see 'if self.Include' below.
+                    #FreeCADGui.doCommand("win = Arch.makeWindowPreset('" + WindowPresets[self.Preset] + "' " + wp + ", window_sill=" + str(self.Sill.Value) + ")")
+                    FreeCADGui.doCommand("win = Arch.makeWindowPreset('" + WindowPresets[self.Preset] + "' " + wp + ")")
                 else:
                     # Window base sketch's placement follow getPoint placement if addon exists but NOT self.Include
                     FreeCADGui.doCommand("win = Arch.makeWindowPreset('" + WindowPresets[self.Preset] + "' " + wp + ", placement=pl, window_sill=" + str(self.Sill.Value) + ")")
@@ -262,6 +265,8 @@ class Arch_Window:
                     FreeCADGui.doCommand("win.Hosts = win.Hosts + [FreeCAD.ActiveDocument." + sibling.Name + "]")
                 if SketchArch:
                     ArchSketchObject.attachToHost(w, target=host, pl=wPl)
+                    # Trigger onChanged() in the window object by setting Window.Sill, after setting the Window's 'initial' placement by attachToHost() above
+                    FreeCADGui.doCommand("win.Sill = "  + str(self.Sill.Value))
 
         self.doc.commitTransaction()
         self.doc.recompute()