if (!is_front_page()) {
echo '';
else {
?> <div id="innerwrapper">
<?php }
}


// SECOND SNIPPET

if (!is_front_page()) {
echo '';
else {
?></div> <!--closing inner wrapper -->
<?php }
}

First snippet would go in before everything, second snippet in after everything hook.

conditional php to display DIV in easy hook

PHP