extend #6777 to have elevation print out as well.

src/bonsai/bonsai/bim/module/drawing/decoration.py

@@ -1205,22 +1205,11 @@ class PlanLevelDecorator(BaseDecorator):
 
             def get_text():
                 abs_z = verts[0].z
-                z = abs_z
-
-                if element:
-                    spatial_container = ifcopenshell.util.element.get_container(element)
-
-                    if spatial_container:
-                        container_obj = tool.Ifc.get_object(spatial_container)
-
-                        if container_obj:
-                            spatial_container_z = container_obj.matrix_world.translation.z
-                            z = abs_z - spatial_container_z
+                z = helper.get_relative_z(obj, element, abs_z)
 
                 rl = self.format_value(context, z)
                 text = "{}{}".format("" if z < 0 else "+", rl)
                 return text
-
             self.draw_dimension_text(
                 context,
                 get_text,

src/bonsai/bonsai/bim/module/drawing/helper.py

@@ -539,3 +539,26 @@ def add_newline_between_words(text: str, newline_at: int) -> str:
         start = space_index + 1  # Skip the space itself
 
     return "\n".join(result)
+
+
+def get_relative_z(obj: bpy.types.Object, element, abs_z: float) -> float:
+    """Return relative Z of an element, accounting for its spatial container.
+
+    Args:
+        obj: The Blender object representing the element.
+        element: The IFC entity for the object.
+        abs_z: The absolute Z value in world coordinates.
+
+    Returns:
+        Relative Z value if the element is inside a spatial container,
+        otherwise the absolute Z.
+    """
+    z = abs_z
+    if element:
+        spatial_container = ifcopenshell.util.element.get_container(element)
+        if spatial_container:
+            container_obj = tool.Ifc.get_object(spatial_container)
+            if container_obj:
+                spatial_container_z = container_obj.matrix_world.translation.z
+                z = abs_z - spatial_container_z
+    return z

src/bonsai/bonsai/bim/module/drawing/svgwriter.py

@@ -1012,7 +1012,9 @@ class SvgWriter:
 
             # TODO: allow metric to be configurable
             def get_text():
-                z = (matrix_world @ points[0].co.xyz).z
+                abs_z = (matrix_world @ points[0].co.xyz).z
+                z = helper.get_relative_z(obj, element, abs_z)
+
                 rl = helper.format_distance(
                     z,
                     precision=self.precision,