St. Mary’s Hospital, Paddington part of the Imperial College Healthcare NHS Trust London, developed a state-of-the-art 16-bed Critical Care Unit which is dedicated to the hospital’s most severely ill adult patients. Selectaglaze was called upon by main contractors, Howard Electrical, to design and install ribbon window secondary units which, in conjunction with the primary windows would help provide the required sterile and controllable environment. This specification included the ability to vary the internal pressure of individual rooms (negative or positive), an important part of combating the spread of infectious diseases, the eradication of dust incursion and the significant reduction of unwanted noise from the busy London environment. Selectaglaze answered the brief with the installation of its Series 45 side hung casements featuring 6mm toughened glass and fitted with special removable key handles, to prevent unauthorised opening of the hospital windows. A total of 62 secondary glazed units were installed.