In 2016 Imperial College London acquired the neighbouring disused Royal Mail Post Sorting Office. Architects Pascall+Watson specified secondary glazing to improve their performance. Over seven different types were installed to match the varying styles; large sweeping curved headed casements were treated with matching sightline Series 41 side hung casements, tall traditional box sash windows were treated with Series 20 and 25 vertical sliding units. Obscurity glass was specified, to prevent distractions for the researchers and staff. The windows overlooking the busy thoroughfares of Exhibition Road and Imperial College Road were fitted with a cavity to provide added noise insulation. With lots of new and costly equipment in the labs and teaching rooms, it was decided to enhance the ground floor window security with Secured By Design accredited units, the Police Preferred Specification. These were manufactured with specialist locking systems and key locking handles. The new secondary glazing in this state-of-the-art engineering facility, sits perfectly in this repurposed former sorting office. The rooms are now quiet and warm, retaining the elegance of the original architectural features.