This answer, elsewhere on this forum, helped:
Hi,
add this line
<div class="control-group">
<div class="control-label"><?php echo $this->form->getLabel('contact_subject'); ?></div>
<div class="controls"><?php echo $this->form->getInput('contact_subject'); ?></div>
</div>
in /templates/jf_calla-exteriors/html/com_contact/contact/default_form.php
The lay-out is still a problem: there is
no blank line before "subject" and the
field is bigger then the other fields. I didn't find how to fix this. Any hints?