Founded in 1876, South Hampstead High School is situated in Hampstead, North-West London. The girls’ school began a substantial rebuild in 2014 as part of an ambitious 8-year plan, which included the transformation of Waterlow Hall (originally constructed in 1988) into an adaptable performing arts centre. Designed by renowned architects Broadway Malyan and Hilson Moran, and constructed by main contractor, 8build, Waterlow Hall can accommodate up to 12 different layouts and put on professional standard concerts for up to 400 people plus a musical ensemble. An acoustic report showed that the internal noise levels within the hall needed to meet Building Bulletin 93 (BB93) which stipulates that performance rooms and multipurpose halls should not exceed 35dB, and ensemble rooms to be no more than 30dB. Selectaglaze was contacted by 8build to come up with the most sympathetic but practical options of secondary glazing to meet the required acoustic insulation of the large new primary windows, whilst ensuring that they could function properly and look aesthetically pleasing. Five Series 15 2-pane horizontal sliders were installed, along with one Series 15 3-pane horizontal sliding unit for a primary window with a wider opening. The secondary glazing was installed using bespoke timber fixing grounds into which it was fully sealed and secured. Selectaglaze was able to achieve the largest cavity available to maximise the acoustic benefits with a glass-to-glass cavity of around 200mm.