Open Entry in a Modal
Ajax is probably the easiest way when using something like Fancybox:
&lt;a data-fancybox data-type=&quot;ajax&quot; data-src=&quot;yoursite.com/houses/house-slug&quot; href=&quot;javascript:;&quot;&gt;
    House page
&lt;/a&gt;

If your house page has content you want to hide when viewed in the modal you can detect whether or not Ajax was used to request the page:
{% if not craft.app.request.isAjax %}
    Your header code
{% endif }

You could also just include the house content on the page, but hidden and use fancybox to reveal it. This is possibly more accessible.