Theme development question regarding layouts

Your consistent/common areas are:

• Header (Including nav)
• Footer
• Sidebar

So you can easily make them accordingly to:

• header.php – get_header();
• footer.php – get_footer();
• sidebar.php – get_sidebar();

And the right content area, as it is inconsistent, so it can be separated into a different page as:

• content.php (general template)
• content-double.php (template 1)
• content-page.php (template 2)
• etc.

And to include them just put the following code accordingly:

<?php get_template_part('content', ''); ?>
<?php get_template_part('content', 'double'); ?>
<?php get_template_part('content', 'page'); ?>

In this way you can part your template into various particles and can include them where necessary. Any question is highly recommended with thanks. 🙂