An extension to an existing portal framed manufacturing building was completed to increase the productive capability and was part of the initial stages of expansion. As the existing facility remained operational we created a separate site access with haul road. The footprint of the extension was excavated and continuous ring beam foundations constructed and heavily reinforced due to ground conditions. A portal steel frame with associated cold rolled purlins and rails was constructed to height of 15m. Masonry walls were constructed to damp proof course and insulated composite wall cladding and roofing installed along with multiple personnel doors and roller shutter entrance ways. The internal floor slab was laid with a laser screed power float finish to within 3mm. The tolerance was tight as equipment was being installed which required precise levels. The floor slab was also fitted with permanent construction joints to enable expansion and compression, preventing cracking. The extension was connected to the existing building through the removal of the building gable end wall. Works to the existing buildings mezzanine floors were required to facilitate the relocation of escape routes including a spiral stair case. A handrail was installed to the mezzanine to give edge protection and the new offices fitted out and new ribbon windows installed. External surface and foul water drainage was installed and connected into the existing system. ACO drainage was fitted to the roller shutter doors and external aprons. An existing lean to was demolished to provide access into the new extension.