diff --git a/src/bonsai/bonsai/bim/module/model/opening.py b/src/bonsai/bonsai/bim/module/model/opening.py
index f50f57bb03..5d147fe520 100644
--- a/src/bonsai/bonsai/bim/module/model/opening.py
+++ b/src/bonsai/bonsai/bim/module/model/opening.py
@@ -26,7 +26,7 @@ import numpy as np
 import ifcopenshell
 import ifcopenshell.api
 import ifcopenshell.api.geometry
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.geom
 import ifcopenshell.util.shape
 import ifcopenshell.util.element
@@ -69,7 +69,7 @@ class FilledOpeningGenerator:
         assert filling and element
         if filling.FillsVoids:
             ifcopenshell.api.run(
-                "void.remove_opening", tool.Ifc.get(), opening=filling.FillsVoids[0].RelatingOpeningElement
+                "feature.remove_feature", tool.Ifc.get(), feature=filling.FillsVoids[0].RelatingOpeningElement
             )
 
         if target is None:
@@ -156,8 +156,8 @@ class FilledOpeningGenerator:
             "geometry.assign_representation", tool.Ifc.get(), product=opening, representation=mapped_representation
         )
 
-        ifcopenshell.api.run("void.add_opening", tool.Ifc.get(), opening=opening, element=element)
-        ifcopenshell.api.run("void.add_filling", tool.Ifc.get(), opening=opening, element=filling)
+        ifcopenshell.api.run("feature.add_feature", tool.Ifc.get(), feature=opening, element=element)
+        ifcopenshell.api.run("feature.add_filling", tool.Ifc.get(), opening=opening, element=filling)
 
         voided_objs = [voided_obj]
         # Openings affect all subelements of an aggregate
@@ -826,7 +826,7 @@ class CloneOpening(Operator, tool.Ifc.Operator):
         new_opening = ifcopenshell.api.run("root.create_entity", tool.Ifc.get(), ifc_class="IfcOpeningElement")
         new_opening.Representation = opening_representation
 
-        ifcopenshell.api.void.add_opening(ifc_file, opening=new_opening, element=voided_element)
+        ifcopenshell.api.feature.add_feature(ifc_file, feature=new_opening, element=voided_element)
         new_opening.ObjectPlacement = opening_placement
 
         # Update affected representations.
diff --git a/src/bonsai/bonsai/bim/module/model/wall.py b/src/bonsai/bonsai/bim/module/model/wall.py
index b848a23f5d..8f776a0b36 100644
--- a/src/bonsai/bonsai/bim/module/model/wall.py
+++ b/src/bonsai/bonsai/bim/module/model/wall.py
@@ -984,7 +984,7 @@ class DumbWallJoiner:
             _, opening_position = mathutils.geometry.intersect_point_line(opening_location.to_2d(), *axis1["reference"])
             if opening_position > cut_percentage:
                 # The opening should be removed from element1.
-                ifcopenshell.api.run("void.remove_opening", tool.Ifc.get(), opening=opening)
+                ifcopenshell.api.run("feature.remove_feature", tool.Ifc.get(), feature=opening)
 
         # Now let's check element2.
         for opening in [
@@ -996,7 +996,7 @@ class DumbWallJoiner:
             _, opening_position = mathutils.geometry.intersect_point_line(opening_location.to_2d(), *axis1["reference"])
             if opening_position < cut_percentage:
                 # The opening should be removed from element2.
-                ifcopenshell.api.run("void.remove_opening", tool.Ifc.get(), opening=opening)
+                ifcopenshell.api.run("feature.remove_feature", tool.Ifc.get(), feature=opening)
 
         # During the duplication process, filled voids are not copied. So we
         # only need to check fillings on the original element1.
diff --git a/src/bonsai/bonsai/bim/module/void/operator.py b/src/bonsai/bonsai/bim/module/void/operator.py
index e592b58810..067dc91332 100644
--- a/src/bonsai/bonsai/bim/module/void/operator.py
+++ b/src/bonsai/bonsai/bim/module/void/operator.py
@@ -87,7 +87,7 @@ class AddOpening(bpy.types.Operator, tool.Ifc.Operator):
                 self.report({"INFO"}, f"An {element1.is_a()} is not allowed to have an opening.")
                 continue
 
-            # Sync placement before void.add_opening.
+            # Sync placement before feature.add_feature.
             if tool.Ifc.is_moved(obj1):
                 bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj1)
 
@@ -109,7 +109,7 @@ class AddOpening(bpy.types.Operator, tool.Ifc.Operator):
                     should_add_representation=True,
                     context=body_context,
                 )
-            ifcopenshell.api.run("void.add_opening", tool.Ifc.get(), opening=element2, element=element1)
+            ifcopenshell.api.run("feature.add_feature", tool.Ifc.get(), feature=element2, element=element1)
 
             if tool.Ifc.is_moved(obj2):
                 bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj2)
@@ -178,7 +178,7 @@ class RemoveOpening(bpy.types.Operator, tool.Ifc.Operator):
             opening_obj.name = "/".join(opening_obj.name.split("/")[1:])
             tool.Ifc.unlink(element=opening)
 
-        ifcopenshell.api.run("void.remove_opening", tool.Ifc.get(), opening=opening)
+        ifcopenshell.api.run("feature.remove_feature", tool.Ifc.get(), feature=opening)
 
         decomposed_building_elements = {element}
         decomposed_building_elements.update(tool.Aggregate.get_parts_recursively(element))
@@ -220,7 +220,7 @@ class AddFilling(bpy.types.Operator, tool.Ifc.Operator):
         if not element_id or not opening_id or element_id == opening_id:
             return {"FINISHED"}
         ifcopenshell.api.run(
-            "void.add_filling", self.file, opening=self.file.by_id(opening_id), element=self.file.by_id(element_id)
+            "feature.add_filling", self.file, opening=self.file.by_id(opening_id), element=self.file.by_id(element_id)
         )
         return {"FINISHED"}
 
@@ -233,10 +233,9 @@ class RemoveFilling(bpy.types.Operator, tool.Ifc.Operator):
 
     def _execute(self, context):
         filling = tool.Ifc.get().by_id(self.filling)
-        filling_obj = tool.Ifc.get_object(filling)
         for rel in filling.FillsVoids:
             bpy.ops.bim.remove_opening(opening_id=rel.RelatingOpeningElement.id())
-        ifcopenshell.api.run("void.remove_filling", tool.Ifc.get(), element=filling)
+        ifcopenshell.api.run("feature.remove_filling", tool.Ifc.get(), element=filling)
         return {"FINISHED"}
 
 
diff --git a/src/bonsai/bonsai/tool/feature.py b/src/bonsai/bonsai/tool/feature.py
index d8bcbfb162..e9a4d9f779 100644
--- a/src/bonsai/bonsai/tool/feature.py
+++ b/src/bonsai/bonsai/tool/feature.py
@@ -40,13 +40,13 @@ class Feature(bonsai.core.tool.Feature):
         for feature_obj in feature_objs:
             feature_element = tool.Ifc.get_entity(feature_obj)
 
-            # Sync placement before void.add_opening.
+            # Sync placement before feature.add_feature.
             if tool.Ifc.is_moved(featured_obj):
                 bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=featured_obj)
 
             element_had_openings = tool.Geometry.has_openings(featured_element)
             body_context = ifcopenshell.util.representation.get_context(tool.Ifc.get(), "Model", "Body")
-            ifcopenshell.api.run("void.add_opening", tool.Ifc.get(), opening=feature_element, element=featured_element)
+            ifcopenshell.api.run("feature.add_feature", tool.Ifc.get(), feature=feature_element, element=featured_element)
 
             if tool.Ifc.is_moved(feature_obj):
                 bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=feature_obj)
diff --git a/src/bonsai/bonsai/tool/root.py b/src/bonsai/bonsai/tool/root.py
index 7b64e173af..7d91716e08 100644
--- a/src/bonsai/bonsai/tool/root.py
+++ b/src/bonsai/bonsai/tool/root.py
@@ -290,8 +290,8 @@ class Root(bonsai.core.tool.Root):
                         product=opening,
                         representation=mapped_representation,
                     )
-                    ifcopenshell.api.run("void.add_opening", tool.Ifc.get(), opening=opening, element=element)
-                    ifcopenshell.api.run("void.add_filling", tool.Ifc.get(), opening=opening, element=filling)
+                    ifcopenshell.api.run("feature.add_feature", tool.Ifc.get(), feature=opening, element=element)
+                    ifcopenshell.api.run("feature.add_filling", tool.Ifc.get(), opening=opening, element=filling)
 
                     voided_objs = [voided_obj]
                     # Openings affect all subelements of an aggregate
diff --git a/src/bonsai/test/tool/test_root.py b/src/bonsai/test/tool/test_root.py
index 79b773d256..0d0e1fdce2 100644
--- a/src/bonsai/test/tool/test_root.py
+++ b/src/bonsai/test/tool/test_root.py
@@ -74,8 +74,8 @@ class TestGetDecompositionRelationships(NewFile):
         element = ifc.createIfcWall()
         opening = ifc.createIfcOpeningElement()
         fill = ifc.createIfcWindow()
-        ifcopenshell.api.run("void.add_opening", ifc, opening=opening, element=element)
-        ifcopenshell.api.run("void.add_filling", ifc, opening=opening, element=fill)
+        ifcopenshell.api.run("feature.add_feature", ifc, feature=opening, element=element)
+        ifcopenshell.api.run("feature.add_filling", ifc, opening=opening, element=fill)
 
         obj = bpy.data.objects.new("Object", None)
         tool.Ifc.link(fill, obj)
diff --git a/src/ifcopenshell-python/ifcopenshell/api/void/__init__.py b/src/ifcopenshell-python/ifcopenshell/api/feature/__init__.py
similarity index 71%
rename from src/ifcopenshell-python/ifcopenshell/api/void/__init__.py
rename to src/ifcopenshell-python/ifcopenshell/api/feature/__init__.py
index 0c5306e46f..41c7c27a6c 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/void/__init__.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/feature/__init__.py
@@ -16,25 +16,26 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
-"""Create void relationships between openings and physical elements
+"""Create relationships between features (e.g. openings) and physical elements
 
-An opening is a special element (created using
+A feature is a special element (created using
 :func:`ifcopenshell.api.root.create_entity`) that may then be used to create
-voids in other elements (such as walls and slabs). These voids may then be
-filled with doors, trapdoors, skylights, and so on.
+geometric changes in other elements (such as walls and slabs). Most commonly, a
+feature would be an opening void. These voids may then be filled with doors,
+trapdoors, skylights, and so on.
 """
 
 from .. import wrap_usecases
+from .add_feature import add_feature
 from .add_filling import add_filling
-from .add_opening import add_opening
+from .remove_feature import remove_feature
 from .remove_filling import remove_filling
-from .remove_opening import remove_opening
 
 wrap_usecases(__path__, __name__)
 
 __all__ = [
+    "add_feature",
     "add_filling",
-    "add_opening",
+    "remove_feature",
     "remove_filling",
-    "remove_opening",
 ]
diff --git a/src/ifcopenshell-python/ifcopenshell/api/feature/add_feature.py b/src/ifcopenshell-python/ifcopenshell/api/feature/add_feature.py
new file mode 100644
index 0000000000..4eb3693d19
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/api/feature/add_feature.py
@@ -0,0 +1,152 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.owner
+import ifcopenshell.api.geometry
+import ifcopenshell.api.aggregate
+import ifcopenshell.guid
+import ifcopenshell.util.element
+import ifcopenshell.util.placement
+
+
+def add_feature(
+    file: ifcopenshell.file, feature: ifcopenshell.entity_instance, element: ifcopenshell.entity_instance
+) -> ifcopenshell.entity_instance:
+    """Create a projecting, voiding, or surface feature in an element
+
+    There are three main types of features: those that add, remove, or
+    influence geometry of a parent object.
+
+    The most common of these is an opening. For example, it is often necessary
+    to cut out openings in elements like walls and slabs to make space to
+    insert doors, windows, and other services that go through these
+    penetrations.
+
+    Whereas it is possible to simply draw the wall as a rectangle with a
+    hole in it for the opening, often these openings have specific meanings.
+    For example, an opening might be filled with a window, and so when the
+    window moves, the opening should move with it. Alternatively, the
+    opening itself might have fire or acoustic requirements, such that any
+    service or equipment passing through that space must also comply with
+    those requirements. For these types of semantic openings, you should
+    have a distinct opening element which voids your regular element. For
+    example, your wall will still be a rectangular prism with no hole in it,
+    and a separate opening element will have a box representing the extents
+    of the opening for a window. The opening element will automatically
+    perform a geometric boolean operation to cut out the wall's geometry.
+
+    Whenever you have an opening in you project, you should determine
+    whether or not the opening is semantic (i.e. should be represented by a
+    distinct opening object) or non-semantic (i.e. should simply be
+    booleaned or be part of the shape of the object).
+
+    :param feature: The IfcFeatureElement to affect the element.
+    :type feature: ifcopenshell.entity_instance
+    :param element: The IfcElement to add the feature to.
+    :type element: ifcopenshell.entity_instance
+    :return: The new IfcRelVoidsElement relationship
+    :rtype: ifcopenshell.entity_instance
+
+    Example:
+
+    .. code:: python
+
+        # A bit of preparation, let's create some geometric contexts since
+        # we want to create some geometry for our wall and opening.
+        model3d = ifcopenshell.api.context.add_context(model, context_type="Model")
+        body = ifcopenshell.api.context.add_context(model,
+            context_type="Model", context_identifier="Body", target_view="MODEL_VIEW", parent=model3d)
+
+        # Create a wall
+        wall = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
+
+        # Let's use the "3D Body" representation we created earlier to add a
+        # new wall-like body geometry, 5 meters long, 3 meters high, and
+        # 200mm thick
+        representation = ifcopenshell.api.geometry.add_wall_representation(model,
+            context=body, length=5, height=3, thickness=0.2)
+        ifcopenshell.api.geometry.assign_representation(model,
+            product=wall, representation=representation)
+
+        # Place our wall at the origin
+        ifcopenshell.api.geometry.edit_object_placement(model, product=wall)
+
+        # Create an opening, such as for a service penetration with fire and
+        # acoustic requirements.
+        opening = ifcopenshell.api.root.create_entity(model, ifc_class="IfcOpeningElement")
+
+        # Let's create an opening representation of a 950mm x 2100mm door.
+        # Notice how the thickness is greater than the wall thickness, this
+        # helps resolve floating point resolution errors in 3D.
+        representation = ifcopenshell.api.geometry.add_wall_representation(model,
+            context=body, length=.95, height=2.1, thickness=0.4)
+        ifcopenshell.api.geometry.assign_representation(model,
+            product=opening, representation=representation)
+
+        # Let's shift our door 1 meter along the wall and 100mm along the
+        # wall, to create a nice overlap for the opening boolean.
+        matrix = np.identity(4)
+        matrix[:,3] = [1, -.1, 0, 0]
+        ifcopenshell.api.geometry.edit_object_placement(model, product=opening, matrix=matrix)
+
+        # The opening will now void the wall.
+        ifcopenshell.api.feature.add_feature(model, feature=opening, element=wall)
+    """
+    if feature.is_a("IfcFeatureElementSubtraction"):
+        rels = feature.VoidsElements
+        ifc_class = "IfcRelVoidsElement"
+    elif feature.is_a("IfcFeatureElementAddition"):
+        rels = feature.ProjectsElements
+        ifc_class = "IfcRelProjectsElement"
+    elif feature.is_a("IfcSurfaceFeature"):
+        if file.schema == "IFC4":
+            return ifcopenshell.api.aggregate.assign_object(file, [feature], element)
+        rels = feature.AdheresToElement
+        ifc_class = "IfcRelAdheresToElement"
+
+    if rels:
+        if rels[0][4] == element:
+            return rels[0]
+        elif ifc_class == "IfcRelAdheresToElement" and len(rels[0].RelatedSurfaceFeatures) != 1:
+            rels[0].RelatedSurfaceFeatures = list(set(rels[0].RelatedSurfaceFeatures) - {feature})
+        else:
+            history = rels[0].OwnerHistory
+            file.remove(rels[0])
+            if history:
+                ifcopenshell.util.element.remove_deep2(file, history)
+
+    rel = file.create_entity(
+        ifc_class,
+        ifcopenshell.guid.new(),
+        ifcopenshell.api.owner.create_owner_history(file),
+        None,
+        None,
+        element,
+        [feature] if ifc_class == "IfcRelAdheresToElement" else feature,
+    )
+
+    if (placement := feature.ObjectPlacement) and placement.is_a("IfcLocalPlacement"):
+        ifcopenshell.api.geometry.edit_object_placement(
+            file,
+            product=feature,
+            matrix=ifcopenshell.util.placement.get_local_placement(placement),
+            is_si=False,
+        )
+
+    return rel
diff --git a/src/ifcopenshell-python/ifcopenshell/api/void/add_filling.py b/src/ifcopenshell-python/ifcopenshell/api/feature/add_filling.py
similarity index 96%
rename from src/ifcopenshell-python/ifcopenshell/api/void/add_filling.py
rename to src/ifcopenshell-python/ifcopenshell/api/feature/add_filling.py
index 0fb7d2e906..7f59d65ec8 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/void/add_filling.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/feature/add_filling.py
@@ -82,7 +82,7 @@ def add_filling(
         ifcopenshell.api.geometry.edit_object_placement(model, product=opening, matrix=matrix)
 
         # The opening will now void the wall.
-        ifcopenshell.api.void.add_opening(model, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(model, feature=opening, element=wall)
 
         # Create a door
         door = ifcopenshell.api.root.create_entity(model, ifc_class="IfcDoor")
@@ -100,7 +100,7 @@ def add_filling(
         ifcopenshell.api.geometry.edit_object_placement(model, product=door, matrix=matrix)
 
         # The door will now fill the opening.
-        ifcopenshell.api.void.add_filling(model, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(model, opening=opening, element=door)
     """
     settings = {"opening": opening, "element": element}
 
diff --git a/src/ifcopenshell-python/ifcopenshell/api/void/remove_opening.py b/src/ifcopenshell-python/ifcopenshell/api/feature/remove_feature.py
similarity index 55%
rename from src/ifcopenshell-python/ifcopenshell/api/void/remove_opening.py
rename to src/ifcopenshell-python/ifcopenshell/api/feature/remove_feature.py
index 21883bcec4..6a1d5e5610 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/void/remove_opening.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/feature/remove_feature.py
@@ -17,44 +17,50 @@
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
 import ifcopenshell.api.root
+import ifcopenshell.api.aggregate
 import ifcopenshell.util.element
 
 
-def remove_opening(file: ifcopenshell.file, opening: ifcopenshell.entity_instance) -> None:
-    """Remove an opening
+def remove_feature(file: ifcopenshell.file, feature: ifcopenshell.entity_instance) -> None:
+    """Remove a feature
 
-    Fillings are retained as orphans. Voided elements remain. Openings
-    cannot exist by themselves, so not only is the opening relationship
-    removed, the opening is also removed.
+    Fillings are retained as orphans. Featured elements remain. Features
+    cannot exist by themselves, so not only is the relationship removed, the
+    feature is also removed.
 
-    :param opening: The IfcOpeningElement to remove.
-    :type opening: ifcopenshell.entity_instance
-    :return: None
-    :rtype: None
+    :param feature: The IfcFeatureElement to remove.
 
     Example:
 
     .. code:: python
 
-        # Create an oprhaned opening. Note that an orphaned opening is
+        # Create an orphaned opening. Note that an orphaned opening is
         # invalid, as an opening can only exist when voiding another
         # element.
-        opening = ifcopenshell.api.root.create_entity(model, ifc_class="IfcOpeningElement")
+        feature = ifcopenshell.api.root.create_entity(model, ifc_class="IfcOpeningElement")
 
         # Remove it. This brings us back to a valid model.
-        ifcopenshell.api.void.remove_opening(model, opening=opening)
+        ifcopenshell.api.feature.remove_feature(model, feature=feature)
     """
-    settings = {"opening": opening}
-
-    for rel in settings["opening"].VoidsElements:
+    if feature.is_a("IfcFeatureElementSubtraction"):
+        rels = feature.VoidsElements
+    elif feature.is_a("IfcFeatureElementAddition"):
+        rels = feature.ProjectsElements
+    elif feature.is_a("IfcSurfaceFeature"):
+        if file.schema == "IFC4":
+            ifcopenshell.api.aggregate.unassign_object(file, products=[feature])
+            rels = []
+        else:
+            rels = feature.ProjectsElements
+    for rel in rels:
         history = rel.OwnerHistory
         file.remove(rel)
         if history:
             ifcopenshell.util.element.remove_deep2(file, history)
-    if settings["opening"].is_a("IfcOpeningElement"):
-        for rel in settings["opening"].HasFillings:
+    if feature.is_a("IfcOpeningElement"):
+        for rel in feature.HasFillings:
             history = rel.OwnerHistory
             file.remove(rel)
             if history:
                 ifcopenshell.util.element.remove_deep2(file, history)
-    ifcopenshell.api.root.remove_product(file, product=settings["opening"])
+    ifcopenshell.api.root.remove_product(file, product=feature)
diff --git a/src/ifcopenshell-python/ifcopenshell/api/void/remove_filling.py b/src/ifcopenshell-python/ifcopenshell/api/feature/remove_filling.py
similarity index 93%
rename from src/ifcopenshell-python/ifcopenshell/api/void/remove_filling.py
rename to src/ifcopenshell-python/ifcopenshell/api/feature/remove_filling.py
index af6d28fc6d..f6931b4f9d 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/void/remove_filling.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/feature/remove_filling.py
@@ -47,10 +47,10 @@ def remove_filling(file: ifcopenshell.file, element: ifcopenshell.entity_instanc
         door = ifcopenshell.api.root.create_entity(model, ifc_class="IfcDoor")
 
         # The door will now fill the opening.
-        ifcopenshell.api.void.add_filling(model, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(model, opening=opening, element=door)
 
         # Not anymore!
-        ifcopenshell.api.void.remove_filling(model, element=door)
+        ifcopenshell.api.feature.remove_filling(model, element=door)
     """
     settings = {"element": element}
 
diff --git a/src/ifcopenshell-python/ifcopenshell/api/root/remove_product.py b/src/ifcopenshell-python/ifcopenshell/api/root/remove_product.py
index 77fbc4264d..2df1b4eaa5 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/root/remove_product.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/root/remove_product.py
@@ -18,7 +18,7 @@
 
 import ifcopenshell.api.type
 import ifcopenshell.api.grid
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.root
 import ifcopenshell.api.pset
 import ifcopenshell.api.boundary
@@ -94,7 +94,7 @@ def remove_product(file: ifcopenshell.file, product: ifcopenshell.entity_instanc
         )
         ifcopenshell.api.geometry.remove_representation(file, **{"representation": representation})
     for opening in getattr(settings["product"], "HasOpenings", []) or []:
-        ifcopenshell.api.void.remove_opening(file, opening=opening.RelatedOpeningElement)
+        ifcopenshell.api.feature.remove_feature(file, feature=opening.RelatedOpeningElement)
 
     if settings["product"].is_a("IfcGrid"):
         for axis in settings["product"].UAxes + settings["product"].VAxes + (settings["product"].WAxes or ()):
diff --git a/src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py b/src/ifcopenshell-python/ifcopenshell/api/void/add_feature.py
similarity index 69%
rename from src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py
rename to src/ifcopenshell-python/ifcopenshell/api/void/add_feature.py
index 8c739ff0e4..7edc696fae 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/void/add_feature.py
@@ -19,19 +19,24 @@
 import ifcopenshell
 import ifcopenshell.api.owner
 import ifcopenshell.api.geometry
+import ifcopenshell.api.aggregate
 import ifcopenshell.guid
 import ifcopenshell.util.element
 import ifcopenshell.util.placement
 
 
-def add_opening(
-    file: ifcopenshell.file, opening: ifcopenshell.entity_instance, element: ifcopenshell.entity_instance
+def add_feature(
+    file: ifcopenshell.file, feature: ifcopenshell.entity_instance, element: ifcopenshell.entity_instance
 ) -> ifcopenshell.entity_instance:
-    """Create an opening in an element
+    """Create a projecting, voiding, or surface feature in an element
 
-    It is often necessary to cut out openings in elements like walls and
-    slabs to make space to insert doors, windows, and other services that go
-    through these penetrations.
+    There are three main types of features: those that add, remove, or
+    influence geometry of a parent object.
+
+    The most common of these is an opening. For example, it is often necessary
+    to cut out openings in elements like walls and slabs to make space to
+    insert doors, windows, and other services that go through these
+    penetrations.
 
     Whereas it is possible to simply draw the wall as a rectangle with a
     hole in it for the opening, often these openings have specific meanings.
@@ -51,9 +56,9 @@ def add_opening(
     distinct opening object) or non-semantic (i.e. should simply be
     booleaned or be part of the shape of the object).
 
-    :param opening: The IfcOpeningElement to cut out the element.
-    :type opening: ifcopenshell.entity_instance
-    :param element: The IfcElement to insert the opening into.
+    :param feature: The IfcFeatureElement to affect the element.
+    :type feature: ifcopenshell.entity_instance
+    :param element: The IfcElement to add the feature to.
     :type element: ifcopenshell.entity_instance
     :return: The new IfcRelVoidsElement relationship
     :rtype: ifcopenshell.entity_instance
@@ -101,36 +106,46 @@ def add_opening(
         ifcopenshell.api.geometry.edit_object_placement(model, product=opening, matrix=matrix)
 
         # The opening will now void the wall.
-        ifcopenshell.api.void.add_opening(model, opening=opening, element=wall)
+        ifcopenshell.api.void.add_feature(model, feature=opening, element=wall)
     """
-    settings = {"opening": opening, "element": element}
+    if feature.is_a("IfcFeatureElementSubtraction"):
+        rels = feature.VoidsElements
+        ifc_class = "IfcRelVoidsElement"
+    elif feature.is_a("IfcFeatureElementAddition"):
+        rels = feature.ProjectsElements
+        ifc_class = "IfcRelProjectsElement"
+    elif feature.is_a("IfcSurfaceFeature"):
+        if file.schema == "IFC4":
+            return ifcopenshell.api.aggregate.assign_object(file, [feature], element)
+        rels = feature.AdheresToElement
+        ifc_class = "IfcRelAdheresToElement"
 
-    voids_elements = settings["opening"].VoidsElements
-
-    if voids_elements:
-        if voids_elements[0].RelatingBuildingElement == settings["element"]:
-            return voids_elements[0]
-        history = voids_elements[0].OwnerHistory
-        file.remove(voids_elements[0])
-        if history:
-            ifcopenshell.util.element.remove_deep2(file, history)
+    if rels:
+        if rels[0][4] == element:
+            return rels[0]
+        elif ifc_class == "IfcRelAdheresToElement" and len(rels[0].RelatedSurfaceFeatures) != 1:
+            rels[0].RelatedSurfaceFeatures = list(set(rels[0].RelatedSurfaceFeatures) - {feature})
+        else:
+            history = rels[0].OwnerHistory
+            file.remove(rels[0])
+            if history:
+                ifcopenshell.util.element.remove_deep2(file, history)
 
     rel = file.create_entity(
-        "IfcRelVoidsElement",
-        **{
-            "GlobalId": ifcopenshell.guid.new(),
-            "OwnerHistory": ifcopenshell.api.owner.create_owner_history(file),
-            "RelatingBuildingElement": settings["element"],
-            "RelatedOpeningElement": settings["opening"],
-        }
+        ifc_class,
+        ifcopenshell.guid.new(),
+        ifcopenshell.api.owner.create_owner_history(file),
+        None,
+        None,
+        element,
+        [feature] if ifc_class == "IfcRelAdheresToElement" else feature,
     )
 
-    placement = getattr(settings["opening"], "ObjectPlacement", None)
-    if placement and placement.is_a("IfcLocalPlacement"):
+    if (placement := feature.ObjectPlacement) and placement.is_a("IfcLocalPlacement"):
         ifcopenshell.api.geometry.edit_object_placement(
             file,
-            product=settings["opening"],
-            matrix=ifcopenshell.util.placement.get_local_placement(settings["opening"].ObjectPlacement),
+            product=feature,
+            matrix=ifcopenshell.util.placement.get_local_placement(placement),
             is_si=False,
         )
 
diff --git a/src/ifcopenshell-python/test/api/void/__init__.py b/src/ifcopenshell-python/test/api/feature/__init__.py
similarity index 100%
rename from src/ifcopenshell-python/test/api/void/__init__.py
rename to src/ifcopenshell-python/test/api/feature/__init__.py
diff --git a/src/ifcopenshell-python/test/api/void/test_add_opening.py b/src/ifcopenshell-python/test/api/feature/test_add_feature.py
similarity index 63%
rename from src/ifcopenshell-python/test/api/void/test_add_opening.py
rename to src/ifcopenshell-python/test/api/feature/test_add_feature.py
index d1abe2aeea..81ed56ff19 100644
--- a/src/ifcopenshell-python/test/api/void/test_add_opening.py
+++ b/src/ifcopenshell-python/test/api/feature/test_add_feature.py
@@ -18,24 +18,44 @@
 
 import numpy
 import test.bootstrap
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.root
 import ifcopenshell.api.unit
 import ifcopenshell.api.geometry
 
 
-class TestAddOpening(test.bootstrap.IFC4):
+class TestAddFeature(test.bootstrap.IFC4X3):
+    def test_adding_a_surface_feature(self):
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        feature = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcSurfaceFeature")
+        ifcopenshell.api.feature.add_feature(self.file, feature=feature, element=wall)
+        assert wall.HasSurfaceFeatures[0].RelatedSurfaceFeatures == (feature,)
+
+
+class TestAddFeature(test.bootstrap.IFC4):
     def test_adding_an_opening(self):
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         assert wall.HasOpenings[0].RelatedOpeningElement == opening
 
+    def test_adding_a_projection(self):
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        projection = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcProjectionElement")
+        ifcopenshell.api.feature.add_feature(self.file, feature=projection, element=wall)
+        assert wall.HasProjections[0].RelatedFeatureElement == projection
+
+    def test_adding_a_surface_feature(self):
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        feature = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcSurfaceFeature")
+        ifcopenshell.api.feature.add_feature(self.file, feature=feature, element=wall)
+        assert wall.IsDecomposedBy[0].RelatedObjects == (feature,)
+
     def test_adding_an_opening_twice(self):
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         assert wall.HasOpenings[0].RelatedOpeningElement == opening
         assert len(wall.HasOpenings) == 1
 
@@ -43,8 +63,8 @@ class TestAddOpening(test.bootstrap.IFC4):
         slab = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcSlab")
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=slab)
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=slab)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         assert not slab.HasOpenings
         assert wall.HasOpenings[0].RelatedOpeningElement == opening
 
@@ -63,7 +83,7 @@ class TestAddOpening(test.bootstrap.IFC4):
         )
         ifcopenshell.api.geometry.edit_object_placement(self.file, product=wall, matrix=matrix1.copy(), is_si=False)
         ifcopenshell.api.geometry.edit_object_placement(self.file, product=opening, matrix=matrix1.copy(), is_si=False)
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         assert opening.ObjectPlacement.PlacementRelTo.PlacesObject[0] == wall
         assert numpy.array_equal(ifcopenshell.util.placement.get_local_placement(opening.ObjectPlacement), matrix1)
 
@@ -74,9 +94,10 @@ class TestAddOpening(test.bootstrap.IFC4):
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         placement = self.file.createIfcGridPlacement()
         opening.ObjectPlacement = placement
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         assert opening.ObjectPlacement == placement
 
 
-class TestAddOpeningIFC2X3(test.bootstrap.IFC2X3, TestAddOpening):
-    pass
+class TestAddFeatureIFC2X3(test.bootstrap.IFC2X3, TestAddFeature):
+    def test_adding_a_surface_feature(self):
+        pass
diff --git a/src/ifcopenshell-python/test/api/void/test_add_filling.py b/src/ifcopenshell-python/test/api/feature/test_add_filling.py
similarity index 81%
rename from src/ifcopenshell-python/test/api/void/test_add_filling.py
rename to src/ifcopenshell-python/test/api/feature/test_add_filling.py
index 7e0e2edabe..49259d75ab 100644
--- a/src/ifcopenshell-python/test/api/void/test_add_filling.py
+++ b/src/ifcopenshell-python/test/api/feature/test_add_filling.py
@@ -17,7 +17,7 @@
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
 import test.bootstrap
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.root
 
 
@@ -25,14 +25,14 @@ class TestAddFilling(test.bootstrap.IFC4):
     def test_adding_a_filling(self):
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         door = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=door)
         assert door.FillsVoids[0].RelatingOpeningElement == opening
 
     def test_adding_a_filling_twice(self):
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         door = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=door)
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=door)
         assert door.FillsVoids[0].RelatingOpeningElement == opening
         assert len(opening.HasFillings) == 1
 
@@ -40,8 +40,8 @@ class TestAddFilling(test.bootstrap.IFC4):
         door = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
         opening1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         opening2 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_filling(self.file, opening=opening1, element=door)
-        ifcopenshell.api.void.add_filling(self.file, opening=opening2, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening1, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening2, element=door)
         assert not opening1.HasFillings
         assert opening2.HasFillings[0].RelatedBuildingElement == door
 
diff --git a/src/ifcopenshell-python/test/api/void/test_remove_opening.py b/src/ifcopenshell-python/test/api/feature/test_remove_feature.py
similarity index 71%
rename from src/ifcopenshell-python/test/api/void/test_remove_opening.py
rename to src/ifcopenshell-python/test/api/feature/test_remove_feature.py
index 02beb80b23..5275639525 100644
--- a/src/ifcopenshell-python/test/api/void/test_remove_opening.py
+++ b/src/ifcopenshell-python/test/api/feature/test_remove_feature.py
@@ -17,21 +17,21 @@
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
 import test.bootstrap
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.root
 
 
-class TestRemoveOpening(test.bootstrap.IFC4):
-    def test_removing_a_simple_opening(self):
-        opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.remove_opening(self.file, opening=opening)
+class TestRemoveFeature(test.bootstrap.IFC4):
+    def test_removing_a_simple_feature(self):
+        feature = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
+        ifcopenshell.api.feature.remove_feature(self.file, feature=feature)
         assert len(list(self.file)) == 0
 
     def test_removing_an_opening_voiding_a_wall(self):
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
-        ifcopenshell.api.void.remove_opening(self.file, opening=opening)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
+        ifcopenshell.api.feature.remove_feature(self.file, feature=opening)
         assert len(self.file.by_type("IfcOpeningElement")) == 0
         assert len(self.file.by_type("IfcRelVoidsElement")) == 0
         assert wall
@@ -40,9 +40,9 @@ class TestRemoveOpening(test.bootstrap.IFC4):
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         door = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=door)
-        ifcopenshell.api.void.remove_opening(self.file, opening=opening)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=door)
+        ifcopenshell.api.feature.remove_feature(self.file, feature=opening)
         assert len(self.file.by_type("IfcOpeningElement")) == 0
         assert len(self.file.by_type("IfcRelVoidsElement")) == 0
         assert len(self.file.by_type("IfcRelFillsElement")) == 0
@@ -50,5 +50,5 @@ class TestRemoveOpening(test.bootstrap.IFC4):
         assert door
 
 
-class TestRemoveOpeningIFC2X3(test.bootstrap.IFC2X3, TestRemoveOpening):
+class TestRemoveFeatureIFC2X3(test.bootstrap.IFC2X3, TestRemoveFeature):
     pass
diff --git a/src/ifcopenshell-python/test/api/geometry/test_edit_object_placement.py b/src/ifcopenshell-python/test/api/geometry/test_edit_object_placement.py
index 7c6bb46b60..70dcbf7285 100644
--- a/src/ifcopenshell-python/test/api/geometry/test_edit_object_placement.py
+++ b/src/ifcopenshell-python/test/api/geometry/test_edit_object_placement.py
@@ -19,7 +19,7 @@
 import numpy
 import pytest
 import test.bootstrap
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.root
 import ifcopenshell.api.unit
 import ifcopenshell.api.system
@@ -303,7 +303,7 @@ class TestEditObjectPlacement(test.bootstrap.IFC4):
                 (0.0, 0.0, 0.0, 1.0),
             )
         )
-        ifcopenshell.api.void.add_opening(self.file, opening=subelement, element=element)
+        ifcopenshell.api.feature.add_feature(self.file, feature=subelement, element=element)
         ifcopenshell.api.geometry.edit_object_placement(self.file, product=element, matrix=matrix.copy(), is_si=False)
         ifcopenshell.api.geometry.edit_object_placement(
             self.file, product=subelement, matrix=submatrix.copy(), is_si=False
@@ -337,8 +337,8 @@ class TestEditObjectPlacement(test.bootstrap.IFC4):
                 (0.0, 0.0, 0.0, 1.0),
             )
         )
-        ifcopenshell.api.void.add_opening(self.file, opening=element, element=wall)
-        ifcopenshell.api.void.add_filling(self.file, element=subelement, opening=element)
+        ifcopenshell.api.feature.add_feature(self.file, feature=element, element=wall)
+        ifcopenshell.api.feature.add_filling(self.file, element=subelement, opening=element)
         ifcopenshell.api.geometry.edit_object_placement(self.file, product=site, matrix=numpy.eye(4), is_si=False)
         ifcopenshell.api.geometry.edit_object_placement(self.file, product=wall, matrix=numpy.eye(4), is_si=False)
         ifcopenshell.api.geometry.edit_object_placement(self.file, product=element, matrix=matrix.copy(), is_si=False)
@@ -564,8 +564,8 @@ class TestEditObjectPlacement(test.bootstrap.IFC4):
         shifted_submatrix = numpy.eye(4)
         shifted_submatrix[:3, 3] = (1, 3, 5)
 
-        ifcopenshell.api.void.add_opening(self.file, opening=subelement, element=element)
-        ifcopenshell.api.void.add_filling(self.file, opening=subelement, element=subsubelement)
+        ifcopenshell.api.feature.add_feature(self.file, feature=subelement, element=element)
+        ifcopenshell.api.feature.add_filling(self.file, opening=subelement, element=subsubelement)
         previous_placement_id = ifcopenshell.api.geometry.edit_object_placement(
             self.file, product=element, matrix=matrix.copy(), is_si=False
         ).id()
diff --git a/src/ifcopenshell-python/test/api/root/test_copy_class.py b/src/ifcopenshell-python/test/api/root/test_copy_class.py
index 01175eb762..66ba27ec06 100644
--- a/src/ifcopenshell-python/test/api/root/test_copy_class.py
+++ b/src/ifcopenshell-python/test/api/root/test_copy_class.py
@@ -21,7 +21,7 @@ import test.bootstrap
 import ifcopenshell.api.unit
 import ifcopenshell.api.type
 import ifcopenshell.api.root
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.pset
 import ifcopenshell.api.group
 import ifcopenshell.api.system
@@ -134,7 +134,7 @@ class TestCopyClass(test.bootstrap.IFC4):
         # IfcOpeningElement opening
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         new = ifcopenshell.api.root.copy_class(self.file, product=wall)
         assert wall.HasOpenings[0] != new.HasOpenings[0]
         assert wall.HasOpenings[0].RelatedOpeningElement == opening
@@ -144,7 +144,7 @@ class TestCopyClass(test.bootstrap.IFC4):
         # IfcVoidingFeature opening
         plate = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcPlate")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcVoidingFeature")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=plate)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=plate)
         new = ifcopenshell.api.root.copy_class(self.file, product=plate)
         assert plate.HasOpenings[0] != new.HasOpenings[0]
         assert plate.HasOpenings[0].RelatedOpeningElement == opening
@@ -155,15 +155,15 @@ class TestCopyClass(test.bootstrap.IFC4):
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         window = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWindow")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=window)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=window)
         new = ifcopenshell.api.root.copy_class(self.file, product=wall)
         assert not new.HasOpenings
 
     def test_copying_an_opening_voiding_an_element(self):
         wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=wall)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=wall)
         new = ifcopenshell.api.root.copy_class(self.file, product=opening)
         assert opening.VoidsElements[0] != new.VoidsElements[0]
         assert new.VoidsElements[0].RelatingBuildingElement == wall
@@ -171,14 +171,14 @@ class TestCopyClass(test.bootstrap.IFC4):
     def test_copying_an_opening_with_a_filling(self):
         door = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=door)
         new = ifcopenshell.api.root.copy_class(self.file, product=opening)
         assert not new.HasFillings
 
     def test_copying_a_filling(self):
         door = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=door)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=door)
         new = ifcopenshell.api.root.copy_class(self.file, product=door)
         assert not new.FillsVoids
 
diff --git a/src/ifcopenshell-python/test/api/root/test_remove_product.py b/src/ifcopenshell-python/test/api/root/test_remove_product.py
index 7b6cef8295..da9b46dbe5 100644
--- a/src/ifcopenshell-python/test/api/root/test_remove_product.py
+++ b/src/ifcopenshell-python/test/api/root/test_remove_product.py
@@ -20,7 +20,7 @@ import test.bootstrap
 import ifcopenshell.api.unit
 import ifcopenshell.api.nest
 import ifcopenshell.api.root
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.grid
 import ifcopenshell.api.type
 import ifcopenshell.api.pset
@@ -159,7 +159,7 @@ class TestRemoveProduct(test.bootstrap.IFC4):
     def test_removing_all_openings_of_an_element(self):
         element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=element)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=element)
         ifcopenshell.api.root.remove_product(self.file, product=element)
         assert len(list(self.file)) == 0
         assert len(self.file.by_type("IfcWall")) == 0
@@ -180,7 +180,7 @@ class TestRemoveProduct(test.bootstrap.IFC4):
         element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         total_entities = len(list(self.file))
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=element)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=element)
         ifcopenshell.api.root.remove_product(self.file, product=opening)
         assert len(list(self.file)) == total_entities
         assert len(self.file.by_type("IfcOpeningElement")) == 0
@@ -191,8 +191,8 @@ class TestRemoveProduct(test.bootstrap.IFC4):
         opening = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         filling = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcDoor")
         total_entities = len(list(self.file))
-        ifcopenshell.api.void.add_opening(self.file, opening=opening, element=element)
-        ifcopenshell.api.void.add_filling(self.file, opening=opening, element=filling)
+        ifcopenshell.api.feature.add_feature(self.file, feature=opening, element=element)
+        ifcopenshell.api.feature.add_filling(self.file, opening=opening, element=filling)
         ifcopenshell.api.root.remove_product(self.file, product=filling)
         assert len(list(self.file)) == total_entities
         assert len(self.file.by_type("IfcDoor")) == 0
diff --git a/src/ifcopenshell-python/test/util/test_element.py b/src/ifcopenshell-python/test/util/test_element.py
index 6ebba1b82a..1ab002f7b0 100644
--- a/src/ifcopenshell-python/test/util/test_element.py
+++ b/src/ifcopenshell-python/test/util/test_element.py
@@ -19,7 +19,7 @@
 import ifcopenshell.api.profile
 import pytest
 import test.bootstrap
-import ifcopenshell.api.void
+import ifcopenshell.api.feature
 import ifcopenshell.api.pset
 import ifcopenshell.api.root
 import ifcopenshell.api.type
@@ -841,8 +841,8 @@ class TestGetDecompositionIFC4(test.bootstrap.IFC4):
         element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
         subelement = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcOpeningElement")
         subsubelement = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWindow")
-        ifcopenshell.api.void.add_opening(self.file, element=element, opening=subelement)
-        ifcopenshell.api.void.add_filling(self.file, element=subsubelement, opening=subelement)
+        ifcopenshell.api.feature.add_feature(self.file, element=element, feature=subelement)
+        ifcopenshell.api.feature.add_filling(self.file, element=subsubelement, opening=subelement)
         results = subject.get_decomposition(element)
         assert subelement in results
         assert subsubelement in results