You can now unload BCF projects to load another one.

src/blenderbim/blenderbim/bim/module/bcf/__init__.py

@@ -57,6 +57,7 @@ classes = (
     operator.SelectBcfBimSnippetReference,
     operator.SelectBcfDocumentReference,
     operator.SelectBcfHeaderFile,
+    operator.UnloadBcfProject,
     operator.ViewBcfTopic,
     prop.BcfReferenceLink,
     prop.BcfLabel,

src/blenderbim/blenderbim/bim/module/bcf/operator.py

@@ -58,7 +58,6 @@ class LoadBcfProject(bpy.types.Operator):
     filter_glob: bpy.props.StringProperty(default="*.bcf;*.bcfzip", options={"HIDDEN"})
 
     def execute(self, context):
-        context.scene.BCFProperties.is_loaded = False
         if self.filepath:
             bcfstore.BcfStore.bcfxml = bcf.bcfxml.load(self.filepath)
         bcfxml = bcfstore.BcfStore.get_bcfxml()
@@ -72,6 +71,17 @@ class LoadBcfProject(bpy.types.Operator):
         return {"RUNNING_MODAL"}
 
 
+class UnloadBcfProject(bpy.types.Operator):
+    bl_idname = "bim.unload_bcf_project"
+    bl_label = "Unload BCF Project"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def execute(self, context):
+        bcfstore.BcfStore.set(None)
+        context.scene.BCFProperties.is_loaded = False
+        return {"FINISHED"}
+
+
 class LoadBcfTopics(bpy.types.Operator):
     bl_idname = "bim.load_bcf_topics"
     bl_label = "Load BCF Topics"

src/blenderbim/blenderbim/bim/module/bcf/ui.py

@@ -39,14 +39,16 @@ class BIM_PT_bcf(Panel):
         scene = context.scene
         props = scene.BCFProperties
 
-        row = layout.row(align=True)
-        row.operator("bim.new_bcf_project", text="New Project")
-        row.operator("bim.load_bcf_project", text="Load Project")
 
         if not props.is_loaded:
+            row = layout.row(align=True)
+            row.operator("bim.new_bcf_project", text="New Project")
+            row.operator("bim.load_bcf_project", text="Load Project")
             return
 
-        row.operator("bim.save_bcf_project", text="Save Project")
+        row = layout.row(align=True)
+        row.operator("bim.save_bcf_project", icon="EXPORT", text="Save Project")
+        row.operator("bim.unload_bcf_project", text="", icon="CANCEL")
 
         row = layout.row()
         row.prop(props, "name")

src/blenderbim/blenderbim/bim/module/project/ui.py

@@ -164,7 +164,7 @@ class BIM_PT_project(Panel):
         op.should_save_as = False
         op = row.operator("export_ifc.bim", icon="FILE_TICK", text="Save As")
         op.should_save_as = True
-        row.operator("bim.unload_project", text="", icon="X")
+        row.operator("bim.unload_project", text="", icon="CANCEL")
 
     def draw_create_project_ui(self, context):
         props = context.scene.BIMProperties