You can only do this if you are using a PHP template to display the results. The logic would be to test if a search has been made. If not, show the default houses using a loop for that, or, if a search has been made, use the loop for the search results. As you are using the Post Type Archive, it is possible that you are using a discrete PHP template. Is this the case, or is the theme a framework, where the archive is made from code hidden in the theme?

So, the logic would look something like this (the ID would match that of the search form):

global $searchandfilter;
$sf_current_query = $searchandfilter->get(1234)->current_query();
if ((!$sf_current_query->is_filtered())&&($sf_current_query->get_search_term()=="")) {
  // the code to display the 8-10 default houses
} else {
  // the normal results loop code here
}

But, I am not sure Avada uses traditional templates, so this may be difficult to code. In the past, other Avada users have needed to use a third party grid plugin, such as this method (which does not offer the option to do as you want in this case):

https://searchandfilter.com/documentation/3rd-party/post-grid/