Substratum acquisition - An acquisition of substratum land is where an Acquiring Authority has compulsorily acquired or proposes to compulsorily acquire land or an interest in land below the surface for the purpose of underground facilities.

Property Condition Survey (PCS) - A property condition survey is an inspection of a building or property to assess and document its general condition. The survey is offered before major construction or tunnelling begins in your area. A post-construction property condition survey will also be offered after completion of construction or tunnelling, if a pre-condition survey was carried out.

Cross passages - Regularly spaced passages that connect traffic tunnels to provide emergency access and contain electrical equipment.

Ventilation and operational equipment tunnels - Ventilation and operational equipment - permanent tunnels required for ventilation, electrical and other services within the interchange. E.g. Ventilation facilities, electrical substations, ventilation and service passages.

Temporary tunnel - Passages required to construct the tunnels efficiently. These tunnels will be backfilled at the end of the project.

Western Harbour Tunnel (WHT) - The Rozelle Interchange project has been contracted to construct the initial section of the WHT from the Rozelle Rail Yards to Emily Street. For any questions about the WHT past Emily Street, please contact Transport for NSW via the community information line at 1800 931 189.