diff --git a/webviz_config/templates/webviz_template.py.jinja2 b/webviz_config/templates/webviz_template.py.jinja2
index 32f994f7..1e256fea 100644
--- a/webviz_config/templates/webviz_template.py.jinja2
+++ b/webviz_config/templates/webviz_template.py.jinja2
@@ -72,37 +72,46 @@ WEBVIZ_STORAGE.storage_folder = path.join(path.dirname(path.realpath(__file__)),
 WEBVIZ_ASSETS.portable = {{ portable }}
 {{ 'WEBVIZ_ASSETS.register_app(app)' if not portable else ''}}
 
-app.layout = dcc.Tabs(parent_className="layoutWrapper",
-                      content_className='pageWrapper',
-                      vertical=True, children=[
-   {% for page in pages %}
-    dcc.Tab(
-        {%- if loop.first -%}
-            id='logo',
-            className='styledLogo',
-        {%- else -%}
-            {%- if loop.last -%}
-                id='last_page',
-            {%- else -%}
-                id='{{page.id}}',
-            {%- endif -%}
-            label='{{page.title}}',
-            selected_className='selectedButton',
-            className='styledButton',
-        {%- endif -%}
-            children=[
-                 {% for content in page.content -%}
-                  {%- if content is string -%}
+if {{ not portable }} and not webviz_config.is_reload_process():
+    # When Dash/Flask is started on localhost with hot module reload activated,
+    # we do not want the main process to call expensive component functions in
+    # the layout tree, as the layout tree used on initialization will anyway be called
+    # from the child/restart/reload process.
+    app.layout = html.Div()
+else:
+    app.layout = dcc.Tabs(
+        parent_className="layoutWrapper",
+        content_className='pageWrapper',
+        vertical=True,
+        children=[
+            {% for page in pages %}
+            dcc.Tab(
+                {%- if loop.first -%}
+                id='logo',
+                className='styledLogo',
+                {%- else -%}
+                {%- if loop.last -%}
+                    id='last_page',
+                {%- else -%}
+                    id='{{page.id}}',
+                {%- endif -%}
+                label='{{page.title}}',
+                selected_className='selectedButton',
+                className='styledButton',
+                {%- endif -%}
+                children=[
+                    {% for content in page.content -%}
+                    {%- if content is string -%}
                     dcc.Markdown(r'''{{ content }}''')
-                  {%- else -%}
+                    {%- else -%}
                     {{ content._call_signature[0] }}.{{ content._call_signature[1] }}
-                  {%- endif -%}
-                  {{- '' if loop.last else ','}}
-                 {% endfor -%}
-                 ]
-    ){{- '' if loop.last else ',' -}}
-  {% endfor %}]
-)
+                    {%- endif -%}
+                    {{- '' if loop.last else ','}}
+                    {% endfor -%}
+                ]
+            ){{- '' if loop.last else ',' -}}
+        {% endfor %}]
+    )
 
 if __name__ == '__main__':
     # This part is ignored when the webviz app is started