diff --git a/src/blenderbim/blenderbim/bim/module/brick/__init__.py b/src/blenderbim/blenderbim/bim/module/brick/__init__.py
index 2b7647dc3c..5e0afa989a 100644
--- a/src/blenderbim/blenderbim/bim/module/brick/__init__.py
+++ b/src/blenderbim/blenderbim/bim/module/brick/__init__.py
@@ -29,6 +29,7 @@ classes = (
     operator.LoadBrickProject,
     operator.NewBrickFile,
     operator.RefreshBrickViewer,
+    operator.RemoveBrick,
     operator.RewindBrickClass,
     operator.ViewBrickClass,
     operator.ViewBrickItem,
diff --git a/src/blenderbim/blenderbim/bim/module/brick/data.py b/src/blenderbim/blenderbim/bim/module/brick/data.py
index 2fc5d38377..072f9b2f70 100644
--- a/src/blenderbim/blenderbim/bim/module/brick/data.py
+++ b/src/blenderbim/blenderbim/bim/module/brick/data.py
@@ -148,7 +148,10 @@ class BrickschemaReferencesData:
     @classmethod
     def libraries(cls):
         results = []
-        for library in tool.Ifc.get().by_type("IfcLibraryInformation"):
+        ifc = tool.Ifc.get()
+        if not ifc:
+            return results
+        for library in ifc.by_type("IfcLibraryInformation"):
             if tool.Ifc.get_schema() == "IFC2X3":
                 results.append((str(library.id()), library.Name or "Unnamed", ""))
             elif ".ttl" in library.Location:
diff --git a/src/blenderbim/blenderbim/bim/module/brick/operator.py b/src/blenderbim/blenderbim/bim/module/brick/operator.py
index 34466f37ad..33d877ebd1 100644
--- a/src/blenderbim/blenderbim/bim/module/brick/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/brick/operator.py
@@ -174,3 +174,18 @@ class RefreshBrickViewer(bpy.types.Operator, Operator):
 
     def _execute(self, context):
         core.refresh_brick_viewer(tool.Brick)
+
+
+class RemoveBrick(bpy.types.Operator, Operator):
+    bl_idname = "bim.remove_brick"
+    bl_label = "Remove Brick"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def _execute(self, context):
+        props = context.scene.BIMBrickProperties
+        core.remove_brick(
+            tool.Ifc,
+            tool.Brick,
+            library=tool.Ifc.get().by_id(int(props.libraries)) if props.libraries else None,
+            brick_uri=props.bricks[props.active_brick_index].uri,
+        )
diff --git a/src/blenderbim/blenderbim/bim/module/brick/ui.py b/src/blenderbim/blenderbim/bim/module/brick/ui.py
index ec9e56b4d1..da3647ab6d 100644
--- a/src/blenderbim/blenderbim/bim/module/brick/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/brick/ui.py
@@ -51,7 +51,11 @@ class BIM_PT_brickschema(Panel):
         row.prop(self.props, "namespace", text="")
         row.prop(self.props, "brick_equipment_class", text="")
         row.operator("bim.add_brick", text="", icon="ADD")
+
+        row = self.layout.row(align=True)
+        row.alignment = "RIGHT"
         row.operator("bim.add_brick_feed", text="", icon="PLUGIN")
+        row.operator("bim.remove_brick", text="", icon="X")
 
         self.layout.template_list("BIM_UL_bricks", "", self.props, "bricks", self.props, "active_brick_index")
 
diff --git a/src/blenderbim/blenderbim/bim/module/patch/operator.py b/src/blenderbim/blenderbim/bim/module/patch/operator.py
index 08fde84fc2..a5c3b19ac6 100644
--- a/src/blenderbim/blenderbim/bim/module/patch/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/patch/operator.py
@@ -121,7 +121,7 @@ class UpdateIfcPatchArguments(bpy.types.Operator):
 
 class RunMigratePatch(bpy.types.Operator):
     bl_idname = "bim.run_migrate_patch"
-    bl_label = "Execute IFCPatch"
+    bl_label = "Run Migrate Patch"
     infile: bpy.props.StringProperty()
     outfile: bpy.props.StringProperty()
     schema: bpy.props.StringProperty()
diff --git a/src/blenderbim/blenderbim/bim/module/pset/ui.py b/src/blenderbim/blenderbim/bim/module/pset/ui.py
index 55df0ec104..9cfca725c7 100644
--- a/src/blenderbim/blenderbim/bim/module/pset/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/pset/ui.py
@@ -192,7 +192,6 @@ class BIM_PT_material_psets(Panel):
     bl_space_type = "PROPERTIES"
     bl_region_type = "WINDOW"
     bl_context = "material"
-    bl_parent_id = "BIM_PT_object_metadata"
 
     @classmethod
     def poll(cls, context):
diff --git a/src/blenderbim/blenderbim/bim/module/system/ui.py b/src/blenderbim/blenderbim/bim/module/system/ui.py
index 594d479e99..b4ce788937 100644
--- a/src/blenderbim/blenderbim/bim/module/system/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/system/ui.py
@@ -121,7 +121,7 @@ class BIM_PT_object_systems(Panel):
             op = row.operator("bim.unassign_system", text="", icon="X")
             op.system = system["id"]
 
-        if not systems_object:
+        if not ObjectSystemData.data["systems"]:
             self.layout.label(text="No System associated with Active Object")
 
 
diff --git a/src/blenderbim/blenderbim/bim/ui.py b/src/blenderbim/blenderbim/bim/ui.py
index cc7f900ba8..23c49c4775 100644
--- a/src/blenderbim/blenderbim/bim/ui.py
+++ b/src/blenderbim/blenderbim/bim/ui.py
@@ -53,7 +53,7 @@ class IFCFileSelector:
                         and filepath[-4:].lower() == ".ifc"
                     ):
                         row = box.row()
-                        op = row.operator("bim.run_migrate_patch")
+                        op = row.operator("bim.run_migrate_patch", text="Upgrade to IFC4")
                         op.infile = filepath
                         op.outfile = filepath[0:-4] + "-IFC4.ifc"
                         op.schema = "IFC4"
diff --git a/src/blenderbim/blenderbim/core/brick.py b/src/blenderbim/blenderbim/core/brick.py
index e5ab6a9bc6..d4df98654e 100644
--- a/src/blenderbim/blenderbim/core/brick.py
+++ b/src/blenderbim/blenderbim/core/brick.py
@@ -100,3 +100,12 @@ def new_brick_file(brick):
 def refresh_brick_viewer(brick):
     brick.run_view_brick_class(brick_class=brick.get_active_brick_class())
     brick.pop_brick_breadcrumb()
+
+
+def remove_brick(ifc, brick, library=None, brick_uri=None):
+    if library:
+        reference = brick.get_library_brick_reference(library, brick_uri)
+        if reference:
+            ifc.run("library.remove_reference", reference=reference)
+    brick.remove_brick(brick_uri)
+    brick.run_refresh_brick_viewer()
diff --git a/src/blenderbim/blenderbim/core/tool.py b/src/blenderbim/blenderbim/core/tool.py
index cdb4c9a651..f3e252f499 100644
--- a/src/blenderbim/blenderbim/core/tool.py
+++ b/src/blenderbim/blenderbim/core/tool.py
@@ -67,6 +67,7 @@ class Brick:
     def load_brick_file(cls, filepath): pass
     def new_brick_file(cls): pass
     def pop_brick_breadcrumb(cls): pass
+    def remove_brick(cls, brick_uri): pass
     def run_assign_brick_reference(cls, element=None, library=None, brick_uri=None): pass
     def run_refresh_brick_viewer(cls): pass
     def run_view_brick_class(cls, brick_class=None): pass
diff --git a/src/blenderbim/blenderbim/tool/brick.py b/src/blenderbim/blenderbim/tool/brick.py
index eb16214b95..8a2cb1d5dd 100644
--- a/src/blenderbim/blenderbim/tool/brick.py
+++ b/src/blenderbim/blenderbim/tool/brick.py
@@ -278,8 +278,9 @@ class Brick(blenderbim.core.tool.Brick):
         return name
 
     @classmethod
-    def run_add_brick_feed(source=None, destination=None):
-        return blenderbim.core.brick.add_brick_feed(tool.Ifc, tool.Brick, source=source, destination=destination)
+    def remove_brick(cls, brick_uri):
+        for triple in BrickStore.graph.triples((URIRef(brick_uri), None, None)):
+            BrickStore.graph.remove(triple)
 
     @classmethod
     def run_assign_brick_reference(cls, element=None, library=None, brick_uri=None):
diff --git a/src/blenderbim/test/bim/feature/brick.feature b/src/blenderbim/test/bim/feature/brick.feature
index 590d6dfbe4..18597c8bdc 100644
--- a/src/blenderbim/test/bim/feature/brick.feature
+++ b/src/blenderbim/test/bim/feature/brick.feature
@@ -50,6 +50,13 @@ Scenario: Assign brick reference
     When I press "bim.assign_brick_reference"
     Then nothing happens
 
+Scenario: Add brick - vanilla brick with no IFC
+    Given an empty Blender session
+    And I press "bim.new_brick_file"
+    And I set "scene.BIMBrickProperties.namespace" to "https://example.org/digitaltwin#"
+    When I press "bim.add_brick"
+    Then nothing happens
+
 Scenario: Add brick - without a brick IFC library
     Given an empty IFC project
     And I add a cube
@@ -58,7 +65,7 @@ Scenario: Add brick - without a brick IFC library
     And I press "bim.assign_class"
     And I press "bim.load_brick_project(filepath='{cwd}/test/files/spaces.ttl')"
     And the object "IfcChiller/Cube" is selected
-    And I set "scene.BIMBrickProperties.namespace" to "http://example.org/digitaltwin#"
+    And I set "scene.BIMBrickProperties.namespace" to "https://example.org/digitaltwin#"
     When I press "bim.add_brick"
     Then nothing happens
 
@@ -71,7 +78,7 @@ Scenario: Add brick - with a brick IFC library
     And I press "bim.load_brick_project(filepath='{cwd}/test/files/spaces.ttl')"
     And I press "bim.convert_brick_project"
     And the object "IfcChiller/Cube" is selected
-    And I set "scene.BIMBrickProperties.namespace" to "http://example.org/digitaltwin#"
+    And I set "scene.BIMBrickProperties.namespace" to "https://example.org/digitaltwin#"
     When I press "bim.add_brick"
     Then nothing happens
 
@@ -79,7 +86,7 @@ Scenario: Add brick feed
     Given an empty IFC project
     And I press "bim.load_brick_project(filepath='{cwd}/test/files/spaces.ttl')"
     And I press "bim.convert_brick_project"
-    And I set "scene.BIMBrickProperties.namespace" to "http://example.org/digitaltwin#"
+    And I set "scene.BIMBrickProperties.namespace" to "https://example.org/digitaltwin#"
     And I add a cube
     And the object "Cube" is selected
     And I set "scene.BIMRootProperties.ifc_class" to "IfcUnitaryEquipment"
@@ -101,7 +108,7 @@ Scenario: Convert IFC to brick
     Given an empty IFC project
     And I press "bim.load_brick_project(filepath='{cwd}/test/files/spaces.ttl')"
     And I press "bim.convert_brick_project"
-    And I set "scene.BIMBrickProperties.namespace" to "http://example.org/digitaltwin#"
+    And I set "scene.BIMBrickProperties.namespace" to "https://example.org/digitaltwin#"
     And I add a cube
     And the object "Cube" is selected
     And I set "scene.BIMRootProperties.ifc_class" to "IfcUnitaryEquipment"
@@ -120,3 +127,16 @@ Scenario: Refresh brick viewer
     And I press "bim.new_brick_file"
     When I press "bim.refresh_brick_viewer"
     Then nothing happens
+
+Scenario: Remove brick - without a brick IFC library
+    Given an empty IFC project
+    And I add a cube
+    And the object "Cube" is selected
+    And I set "scene.BIMRootProperties.ifc_class" to "IfcChiller"
+    And I press "bim.assign_class"
+    And I press "bim.load_brick_project(filepath='{cwd}/test/files/spaces.ttl')"
+    And the object "IfcChiller/Cube" is selected
+    And I set "scene.BIMBrickProperties.namespace" to "https://example.org/digitaltwin#"
+    And I press "bim.add_brick"
+    When I press "bim.remove_brick"
+    Then nothing happens
diff --git a/src/blenderbim/test/core/test_brick.py b/src/blenderbim/test/core/test_brick.py
index 23aa28e9a7..2b5eb70855 100644
--- a/src/blenderbim/test/core/test_brick.py
+++ b/src/blenderbim/test/core/test_brick.py
@@ -165,3 +165,23 @@ class TestRefreshBrickViewer:
         brick.run_view_brick_class(brick_class="class").should_be_called()
         brick.pop_brick_breadcrumb().should_be_called()
         subject.refresh_brick_viewer(brick)
+
+
+class TestRemoveBrick:
+    def test_run(self, ifc, brick):
+        brick.get_library_brick_reference("library", "brick_uri").should_be_called().will_return("reference")
+        ifc.run("library.remove_reference", reference="reference").should_be_called()
+        brick.remove_brick("brick_uri").should_be_called()
+        brick.run_refresh_brick_viewer().should_be_called()
+        subject.remove_brick(ifc, brick, library="library", brick_uri="brick_uri")
+
+    def test_do_not_remove_reference_if_no_reference_exists(self, ifc, brick):
+        brick.get_library_brick_reference("library", "brick_uri").should_be_called().will_return(None)
+        brick.remove_brick("brick_uri").should_be_called()
+        brick.run_refresh_brick_viewer().should_be_called()
+        subject.remove_brick(ifc, brick, library="library", brick_uri="brick_uri")
+
+    def test_do_not_check_references_if_no_library_specified(self, ifc, brick):
+        brick.remove_brick("brick_uri").should_be_called()
+        brick.run_refresh_brick_viewer().should_be_called()
+        subject.remove_brick(ifc, brick, library=None, brick_uri="brick_uri")
diff --git a/src/blenderbim/test/files/spaces.ttl b/src/blenderbim/test/files/spaces.ttl
index 760a53f1bb..32d05bdf3a 100644
--- a/src/blenderbim/test/files/spaces.ttl
+++ b/src/blenderbim/test/files/spaces.ttl
@@ -1,4 +1,4 @@
-@prefix digitaltwin: <http://example.org/digitaltwin#> .
+@prefix digitaltwin: <https://example.org/digitaltwin#> .
 @prefix brick: <https://brickschema.org/schema/Brick#> .
 @prefix unit: <http://qudt.org/vocab/unit/> .
 @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
diff --git a/src/blenderbim/test/tool/test_brick.py b/src/blenderbim/test/tool/test_brick.py
index 65bee9dbc9..855600d27b 100644
--- a/src/blenderbim/test/tool/test_brick.py
+++ b/src/blenderbim/test/tool/test_brick.py
@@ -345,6 +345,18 @@ class TestPopBrickBreadcrumb(NewFile):
         assert bpy.context.scene.BIMBrickProperties.brick_breadcrumbs[0].name == "foo"
 
 
+class TestRemoveBrick(NewFile):
+    def test_run(self):
+        BrickStore.graph = brickschema.Graph()
+        result = subject.add_brick("http://example.org/digitaltwin#", "https://brickschema.org/schema/Brick#Equipment")
+        subject.remove_brick(result)
+        assert not list(
+            BrickStore.graph.triples(
+                (URIRef(result), None, None)
+            )
+        )
+
+
 class TestRunAssignBrickReference(NewFile):
     def test_nothing(self):
         pass
diff --git a/src/ifc4d/README.md b/src/ifc4d/README.md
index c841b270ea..c774d01f07 100644
--- a/src/ifc4d/README.md
+++ b/src/ifc4d/README.md
@@ -3,14 +3,20 @@
 Ifc4D contains a series of utilities for converting to and from various 4D software. Currently supported:
 
  - Microsoft Project to IFC
- - Oracle Primavera 6 (P6) to IFC
+ - Oracle Primavera 6 (P6) XML to IFC
+ - Oracle Primavera 6 (P6) XER to IFC
+ - Asta Powerproject to IFC
 
 Planned (would you like to contribute? Please reach out!):
 
  - IFC to Microsoft Project
  - IFC to Oracle Primavera 6 (P6)
- - Asta Powerproject to IFC
  - IFC to Asta Powerproject
  - LibreProject to IFC
  - IFC to LibreProject
  - IFC to Gantt
+
+
+## Useful links
+
+ - [P6 EPPM XER Import/Export Data Map Guide](https://docs.oracle.com/cd/F12057_01/English/Mapping_and_Schema/xer_import_export_data_map_project/helpmain.htm?toc.htm?97881.htm)