Do you mean a class that lets you wrap html elements? Or classes that generates the data for the header/body/footer/navbar?
I usually create a public function called show in all my classes to produce output.
wrapper.php
$strResult
|-- <---class_header->show();
|---<---class_body->show();
|---<---class_footer->show();
|---<---class_navbar->show();
wrapper.php::echo($strResult);
Or you could use a template to compile all these together.