Respond to these showcases www. ajplus. co. uk/ajdirect Readers may obtain information about these products by filling in the enquiry numbers on an AJ enquiry card. Advertisers wishing to promote their products on these pages should contact Chris Bond on 020 75056816 For the red-brick elevations of Queens University's David Kerr Building in Belfast, replicas of the beautiful 1940s arched steel windows were created in high-performance aluminium and fabricated by Douglas Architectural Systems. System 11 architectural subframes and System 4 casements were ideal.