Adding a new layout for genesis

I have attempted answering my own question with the following code:

// Added to layout.php in /genesis/lib/structure.php

add_action('genesis_before', 'modalwindow_layout_logic');

    function modalwindow_layout_logic() {

        $site_layout = genesis_site_layout();

        if ( $site_layout == 'modalwindow' ) {
            // Remove default genesis sidebars
            remove_action( 'genesis_after_content', 'genesis_get_sidebar' );
            remove_action( 'genesis_after_content_sidebar_wrap', 'genesis_get_sidebar_alt');
            remove_action( 'genesis_footer', 'genesis_do_footer' );  
            remove_action( 'genesis_header', 'genesis_do_header' );  
            // Remove layout specific sidebars
            remove_action('genesis_before_header', 'genesis_do_nav');
            remove_action('genesis_after_header', 'genesis_do_subnav');
            remove_action('genesis_header', 'genesis_do_nav');
            remove_action('genesis_footer','themedy_footer_menu');
            remove_action('genesis_before_loop', 'genesis_do_breadcrumbs'); // Remove Breadcrumbs by default
            remove_action('genesis_after_header','themedy_secondary_area');
        }
    }

There seems to be more that needs removing- any idea?
Thanks