Fore a region to render if it has a template file (region--regionnname.tpl.php) even if it is empty

force-region-render.php

// Implement a page alter to force certain regions to display even if no blocks exist
function THEMENAME_page_alter(&$page) {
  foreach (system_region_list($GLOBALS['theme'], REGIONS_ALL) as $region => $name) {
    if (in_array($region, array('REGIONNAME'))) {
      $page['REGIONNAME'] = array(
                '#region' => 'REGIONNAME',
                '#weight' => '-10',
                '#theme_wrappers' => array('region'),
      );
    }
  }
}

// Don't forget to remove the if content not empty statement in the region tpl