Wrapper with block

/stash_templates/layouts/page.html (wrapper)

<!doctype html>
<html>
<head>
    {snippet:html-head}
</head>
<body>
    <div class="body-container">

        {snippet:header}

        {exp:stash:block name="main"}
        <div>
            <main role="main" class="page-main">
                <header class="page-title">
                    <h1>{layout:title}</h1>
                </header>
 
                <div class="page-main-container">
                    {if layout:breadcrumbs}
                    <nav class="nav-breadcrumb">
                        <ul>
                            {layout:breadcrumbs}
                        </ul>
                    </nav>
                    {/if}
 
                    <section class="page-content">
                        {layout:content}
                    </section>
                </div>
            </main>
 
            {if layout:sidebar}
            <aside class="page-sidebar">
                {layout:sidebar}
            </aside>
            {/if}
        </div>
        {/exp:stash:block}
 
        {snippet:footer}
        {snippet:scripts}
 
    </div>

</body>
</html>

/default_site/site/index.html (homepage)

    {stash:embed:layouts:page}
    {exp:stash:extend name="main" with="partials:home"}

    {!-- capture data here --}

/stash_templates/partials/home.html (wrapper)

    {!-- your custom homepage layout --}

croxton/gist:a5f953dc5da3bfee9a8e