diff --git a/cara/apps/templates/base/calculator.form.html.j2 b/cara/apps/templates/base/calculator.form.html.j2
index 5880730e..3872475e 100644
--- a/cara/apps/templates/base/calculator.form.html.j2
+++ b/cara/apps/templates/base/calculator.form.html.j2
@@ -77,9 +77,11 @@
     <hr width="80%">
 
     <b>Room data:</b>
+    {% block room_data %}
     <div data-tooltip="The area you wish to study (choose one of the 2 options). Indicate if a central (radiator-type) heating system is in use.">
         <span class="tooltip_text">?</span>
     </div>
+    {% endblock room_data %}
     
     <br>