diff --git a/src/blenderbim/blenderbim/bim/module/qto/helper.py b/src/blenderbim/blenderbim/bim/module/qto/helper.py
index 80dd27b565..09908fb6a8 100644
--- a/src/blenderbim/blenderbim/bim/module/qto/helper.py
+++ b/src/blenderbim/blenderbim/bim/module/qto/helper.py
@@ -67,26 +67,27 @@ def calculate_formwork_area(objs, context):
     copied_objs = []
     result = 0
 
-    for obj in objs:
-        new_obj = obj.copy()
-        new_obj.data = obj.data.copy()
-        new_obj.animation_data_clear()
-        context.collection.objects.link(new_obj)
-        copied_objs.append(new_obj)
+    copied_obj = objs[0].copy()
+    copied_obj.data = objs[0].data.copy()
+    copied_obj.animation_data_clear()
+    context.collection.objects.link(copied_obj)
 
     if len(objs) > 1:
-        context_override = {}
-        context_override["object"] = context_override["active_object"] = copied_objs[0]
-        context_override["selected_objects"] = context_override["selected_editable_objects"] = copied_objs
-        bpy.ops.object.join(context_override)
+        for i, obj in enumerate(objs):
+            if i == 0:
+                continue
+            modifier = copied_obj.modifiers.new(type="BOOLEAN", name="Boolean")
+            modifier.operation = "UNION"
+            modifier.object = obj
+            bpy.ops.object.modifier_apply({"object": copied_obj}, modifier="Boolean")
 
-    copied_objs[0].name = "Formwork"
-    copied_objs[0].BIMObjectProperties.ifc_definition_id = 0
-    modifier = copied_objs[0].modifiers.new("Formwork", "REMESH")
+    copied_obj.name = "Formwork"
+    copied_obj.BIMObjectProperties.ifc_definition_id = 0
+    modifier = copied_obj.modifiers.new("Formwork", "REMESH")
     modifier.mode = "SHARP"
     # This hardcoded value may be optimised through a better understanding of the octree division.
     # These values are based off some trial and error heuristics I've learned through experience.
-    max_dim = max(copied_objs[0].dimensions)
+    max_dim = max(copied_obj.dimensions)
     if max_dim > 45:
         modifier.octree_depth = 9
     elif max_dim > 35:
@@ -98,7 +99,7 @@ def calculate_formwork_area(objs, context):
     else:
         modifier.octree_depth = 5
 
-    mesh = copied_objs[0].evaluated_get(context.evaluated_depsgraph_get()).to_mesh()
+    mesh = copied_obj.evaluated_get(context.evaluated_depsgraph_get()).to_mesh()
     for polygon in mesh.polygons:
         if polygon.normal.z > 0.5:
             continue
diff --git a/src/blenderbim/test/bim/feature/qto.feature b/src/blenderbim/test/bim/feature/qto.feature
index 3f2a737489..9fa0e005ff 100644
--- a/src/blenderbim/test/bim/feature/qto.feature
+++ b/src/blenderbim/test/bim/feature/qto.feature
@@ -28,3 +28,13 @@ Scenario: Calculate object volumes
     And the object "Cube" is selected
     When I press "bim.calculate_object_volumes"
     Then "scene.BIMQtoProperties.qto_result" is "8.0"
+
+Scenario: Calculate formwork areas
+    Given an empty Blender session
+    And I add a cube
+    And I add a cube of size "1" at "1,0,0"
+    And the object "Cube" is selected
+    And additionally the object "Cube.001" is selected
+    When I set "scene.BIMQtoProperties.qto_methods" to "FORMWORK"
+    And I press "bim.execute_qto_method"
+    Then "scene.BIMQtoProperties.qto_result" is "21.5"
diff --git a/src/blenderbim/test/bim/test_feature.py b/src/blenderbim/test/bim/test_feature.py
index 7a547c66e8..3687f7efd2 100644
--- a/src/blenderbim/test/bim/test_feature.py
+++ b/src/blenderbim/test/bim/test_feature.py
@@ -99,6 +99,7 @@ def i_add_a_cube():
     bpy.ops.object.modifier_add(type="ARRAY")
 
 
+@given(parsers.parse('I add a cube of size "{size}" at "{location}"'))
 @when(parsers.parse('I add a cube of size "{size}" at "{location}"'))
 def i_add_a_cube_of_size_size_at_location(size, location):
     bpy.ops.mesh.primitive_cube_add(size=float(size), location=[float(co) for co in location.split(",")])