You can do this by overriding theme, There are many way to do this.
but here is simple one:
function body()
{
$this->output('<body');
$this->body_tags();
$this->output('>');
$this->body_script();
if( strlen(qa_request()) == 0){
///function for your home page style
$this-> my_home();
}else{
// this portion will load if not home
$this->body_header();
$this->body_content();
$this->body_footer();
$this->body_hidden();
}
$this->output('</body>');
}
function my_home(){
//your layout here
}
Please let me know, if anything is worng