A Duratherm curtain-wall system achieves the pavilion/belvedere effect. Hidden frame detailing on the windows minimizes vertical mullions. Large multi-panel lift/slide doors, set at 90 degrees to each other, stack in their respective pockets for a column-free open corner. After one custom window manufacturer proved unequal to the task, recalls the project architect, “we turned to Duratherm and they made our design work.”