With lighting key to the building's atrium refurbishment, our task was to design a bespoke luminaire connected to photocell and timer controls to make full use of the natural daylight. Our solution was to create dramatic 3m-high lightboxes to fit perfectly within the window mullions. To retain the window manufacturer's guarantee we had to devise an ingenious system to clamp the lightboxes into place without altering the light effect within the atrium.