What are the NCC requirements for acoustic separation in multi-storey residential buildings in Australia?

The National Construction Code (NCC) specifies stringent acoustic separation requirements for multi-storey residential buildings in Australia. Volume Two, specifically P2.4.6, details minimum Sound Transmission Class (STC) ratings for airborne sound and Weighted Standardised Impact Sound Pressure Level (Ln,w) ratings for impact sound. Floors separating sole-occupancy units must achieve an STC of at least 50 and an Ln,w of no more than 62. Walls separating units typically require an STC of 50. These provisions aim to minimise noise transfer, ensuring occupant amenity and wellbeing, and are crucial for compliance in Australian residential development.