Motivated to give back to their long-time gym trainer and friend, Mark, dance superstar-siblings Derek and Julianne Hough pop and pivot to complete a surprise renovation on Celebrity IOU. After a decade of renting his condo in Southern California, Mark was finally able to purchase it for himself — only to have the pandemic shutter the doors of his gym. Now, Mark trains clients out of his home. Derek and Julianne knew Mark needed a space that fits his aesthetic and his lifestyle, so they turned to Property Brothers Drew and Jonathan Scott.