diff --git a/src/nav2_turtlebot_simulator/launch/simulator.launch.py b/src/nav2_turtlebot_simulator/launch/simulator.launch.py
index 2ac775e..32e6caa 100644
--- a/src/nav2_turtlebot_simulator/launch/simulator.launch.py
+++ b/src/nav2_turtlebot_simulator/launch/simulator.launch.py
@@ -12,8 +12,39 @@ from launch.substitutions import LaunchConfiguration
 from launch_ros.actions import Node
 
 
+HOUSE_FURNITURE_BOXES = {
+    # mailbox.dae uses inch units and an internal transform. These values preserve
+    # its rendered bounds while keeping the visual box upright on the floor.
+    'mailbox/': ('0.133 0.355 1.067', '0.002 0.017 0.533 0 0 0'),
+    'cafe_table/': ('0.94 0.94 0.78', None),
+    'first_2015_trash_can/': ('0.44 0.44 0.76', None),
+    'table_marble/': ('1.40 0.86 0.76', None),
+}
+
+
+def replace_house_visual_meshes_with_boxes(house_model):
+    """Keep physical mesh collisions, but render furniture as inexpensive boxes."""
+    for visual in house_model.findall('.//visual'):
+        geometry = visual.find('geometry')
+        mesh = geometry.find('mesh') if geometry is not None else None
+        uri = mesh.findtext('uri', default='') if mesh is not None else ''
+        box_config = next((value for key, value in HOUSE_FURNITURE_BOXES.items() if key in uri), None)
+        if box_config is None:
+            continue
+
+        size, pose = box_config
+        geometry.remove(mesh)
+        box = ET.SubElement(geometry, 'box')
+        ET.SubElement(box, 'size').text = size
+        if pose is not None:
+            visual_pose = visual.find('pose')
+            if visual_pose is None:
+                visual_pose = ET.SubElement(visual, 'pose')
+            visual_pose.text = pose
+
+
 def create_flat_house_world(gazebo_dir):
-    """Create a texture-free copy of the house model while retaining its mesh hierarchy."""
+    """Create a texture-free house copy with box-rendered furniture."""
     world_path = os.path.join(gazebo_dir, 'worlds', 'turtlebot3_house.world')
     model_path = os.path.join(gazebo_dir, 'models', 'turtlebot3_house', 'model.sdf')
     flat_models_dir = os.path.join(tempfile.gettempdir(), 'nav2_flat_models')
@@ -23,6 +54,7 @@ def create_flat_house_world(gazebo_dir):
     house_model_tree = ET.parse(model_path)
     house_model = house_model_tree.getroot()
     house_model.attrib['name'] = 'turtlebot3_house_flat'
+    replace_house_visual_meshes_with_boxes(house_model)
 
     for visual in house_model.findall('.//visual'):
         material = visual.find('material')
@@ -47,6 +79,11 @@ def create_flat_house_world(gazebo_dir):
             shadows = ET.SubElement(visual, 'cast_shadows')
         shadows.text = 'false'
 
+        lighting = visual.find('lighting')
+        if lighting is None:
+            lighting = ET.SubElement(visual, 'lighting')
+        lighting.text = 'false'
+
     # ElementTree serializes Gazebo's frame='' as frame="", which is invalid SDF.
     for element in house_model.iter():
         if element.attrib.get('frame') == '':