275 George Street

The project at 275 George Street in Sydney's bustling Central Business District involved the complex demolition of a 16-storey high-rise building, including a two-level plant room. The building, a conventionally reinforced concrete-framed structure, required careful planning and execution due to its location in the CBD and the presence of hazardous materials. DECC was engaged as the Principal Contractor to oversee the demolition, hazardous materials removal, site retention, and bulk excavation.

Our ability to manage hazardous materials, coordinate with stakeholders, and execute precise demolition and excavation works ensured the project’s success, contributing to the ongoing development and transformation of Sydney’s CBD.

Demolition of High Rise Building: The demolition involved the complete dismantling of a 57-meter-tall building, including a two-level plant room. The structure consisted of approximately 25,000 tonnes of reinforced concrete, which was systematically demolished using heavy machinery such as 70-tonne excavators equipped with hydraulic hammers and shears. The demolition was conducted while ensuring minimal disruption to surrounding structures and businesses.

Hazardous Materials Removal: The project required the removal of approximately 1,500m² of hazardous materials, including asbestos, synthetic mineral fibres (SMF), and polychlorinated biphenyls (PCBs). These materials were safely removed following rigorous safety protocols, ensuring compliance with all environmental and safety regulations. The process was certified by clearance certificates issued by a licensed hygienist.

Site Retention and Stabilisation: Comprehensive site retention measures were implemented, including the installation of 150 anchors, 1,000m² of shotcrete, and whalers to stabilise the site during and after demolition. These measures were critical to maintaining the structural integrity of the site, especially given its proximity to other high-rise buildings in the CBD.

Excavation in Class 1 Sandstone: The project involved the bulk excavation of two basement levels, which required the removal of approximately 12,000m³ of material, including excavation through Class 1 sandstone. The excavation was managed using specialised equipment, including 48-tonne excavators with rock-breaking attachments, to ensure precision and prevent damage to surrounding infrastructure.

Materials Handling and Waste Management: Waste generated from the demolition, including concrete, steel, and hazardous materials, was carefully separated and processed. Approximately 10,000 tonnes of concrete and 2,500 tonnes of steel were sent to recyclers, while asbestos-contaminated materials were disposed of at a licensed landfill. A materials handling chute was set up within the building to safely transport debris to ground level for processing.