PHP how to build html in class

I am used to procedural PHP. However, I have a piece of code that needs to be repeated a lot. I was thinking of trying my hand at creating a class. All is going well and it is working, but I think it can be done better. Especially the function where I am creating the HTML. At the moment, I have a variable $html and I keep adding data to it. It feels clunky and I wanted to know if anyone knows of a better solution.

I have been spending hours on Google trying to find a better way of doing it. Has anyone got advice or a link to a good tutorial?

Thank you in advance. Here is the class.

class clerksection {
    var $header;
    var $post;
    var $meta;

    function __construct($post, $meta, $header) {
        $this->post = $post;
        $this->meta = $meta;
        $this->header = $header;
    }

    //PHP magic methods to get values
    public function __get($property) {
        if (property_exists($this, $property)) {
            return $this->$property;
        }
    }

    //PHP magic methods to set values
    public function __set($property, $value) {
        if (property_exists($this, $property)) {
            $this->$property = $value;
        }
        return $this;
    }

    function create_html () {
        $repeat_group = get_post_meta( $this->post, $this->meta, true );
        $uid = spl_object_hash($this);
        $html = '<h2><strong>'. $this->header .'</strong></h2>';
        $html .= '<div class="row">';
        $i = 1;
        foreach( (array) $repeat_group as $key => $value ) :
            $html .= '<div class="col-lg-4 pd_left_15">';
            $html .= '<div class="pd_btm_20">';
            if (!empty($value['image'])) :
            $html .= '<img src="' . $value['image'] . '" class="img-responsive"/>';
            endif;
            $html .= '<p class="clerk_thick"><strong>' . $value['title'] . '</strong></p>';
            $html .= '<p class="dark_color clerk_thin"><strong>' . $value['name'] . '</strong>';
            if (!empty($value['notes'])) :
                $html .= '<a role="button" data-toggle="collapse" href="#' . $uid . $i . '" aria-expanded="false" aria-controls="' . $uid . $i . '">(more)</a>';
            endif;
            $html .= '</p>'; //.dark_color .clerk_thin
            if (!empty($value['notes'])) :
                $html .= '<p class="clerk_thin collapse" id="' . $uid . $i . '">' . $value['notes'] .'</p>';
            endif;
            if (!empty($value['phone'])) :
            $html .= '<p class="clerk_thin"><i class="fa fa-phone dark_color"></i> ' . $value['phone'] . '</p>';
            endif;
            if (!empty($value['email'])) :
            $html .= '<p class="clerk_thin"><i class="fa fa-envelope-o dark_color"></i> <a href="mailto:' . $value['email'] . '" target="_top"> ' . $value['email'] . '</a></p>';
            endif;
            $html .= '</div>'; //.pd_btm_20
            $html .= '</div>'; //.col-lg-4 .pd_left_15
            $i++;
        endforeach;
        $html .= '</div>'; //.row

        return $html;
    }
}