Mandatory house number in address

add_action('woocommerce_checkout_process', 'custom_validation_process');

function custom_validation_process()
{
    global $woocommerce;

    if(isset($_POST['billing_address_1']) and $_POST['billing_address_1'] != '')
    {
        if (!preg_match('/([0-9]+)/Uis', $_POST['billing_address_1']))
        {
            if(function_exists('wc_add_notice'))
                wc_add_notice( __('You must enter your house number for the billing address'), 'error' );
            else
                $woocommerce->add_error( __('You must enter your house number for the billing address') );
        }
    }

    if(isset($_POST['ship_to_different_address']))
    {
        if(isset($_POST['shipping_address_1']) and $_POST['shipping_address_1'] != '')
        {
            if (!preg_match('/([0-9]+)/Uis', $_POST['shipping_address_1']))
            {
                if(function_exists('wc_add_notice'))
                    wc_add_notice( __('You must enter your house number for the shipping address'), 'error' );
                else
                    $woocommerce->add_error( __('You must enter your house number for the shipping address') );
            }
        }
    }
}