You miss a paranthesis. The whole if-statement should be within one paranthesis:
if (($row_owners['status'] == "1") && ($row_owners['display_address'] == "YES"))
{
echo $row_owners['houseno'];
}
else
{
echo "Restricted by owner";
}
I added { and } as well since I always use them. It have saved me from problem when I have changed something in the if-statement, for example adding a echo to debug it.