Maintain breadcrumbs region even when blank?

This is soooo petty and of no real consequence other than minor cosmetics, but...

How can I maintain a blank space in 'home' i.e., when no breadcrumb will be displayed?
At present the space collapses, then the left sidebar drops to accommodate it when moving away from 'home'. (I do hope that makes sense!)

I'm pretty sure it's going to be something simple in 'page.tpl.php' around:

      <?php if ($header || $breadcrumb): ?>

      <div id="header-region"> <?php print $breadcrumb; ?>

      </div>

      <?php endif; ?>
      <?php if ($header || $breadcrumb): ?>

      <div id="header-region"> <?php print $breadcrumb; ?>

      </div>

      <?php endif; ?>

... but I can't quite figure what part :-)