Subterranean termites enter buildings through concealed pathways: slab penetrations, construction joints, and the gap between the slab edge and external walls. Once the home is finished, those entry points are hidden behind concrete, brickwork and cladding. The only time they can be fully protected is during construction.
The National Construction Code requires termite risk management for new homes built in designated termite risk areas, and AS 3660.1 is the Australian Standard that sets out how pre construction termite management systems must be designed and installed. South West Sydney sits within an active subterranean termite region, so your building certifier will expect a compliant system and a certificate of installation before sign off.
Installing protection at the build stage is also significantly cheaper than retrofitting. Once a home is complete, achieving equivalent protection means drilling, trenching and chemical soil treatment around an established structure. And the financial exposure is real: termite damage is generally not covered by standard Australian home insurance policies, so the build stage is the one cheap window you get to deal with the risk properly.