When is the NBN coming to Chirnside Park?

It was being installed along Grandvalley Drv today out the front of our place today. Not sure how long it will be before it is usable. Time will tell!

Depends.
The current Govt/NBN 3 year plan only lists Chirnside Park as a NBN/HFC area to "begin construction" in 2016H2.
However there are significant parts of Chirnside Park that do not have HFC.
When contacting the local MP's office (Tony Smith), the staff inquired with the Dept of Communications to find out about the Non HFC areas of Chirnside Park. The reply was that the Non HFC area would be done with FTTN during the 3 year plan.
Yet, no public document supporting this answer has been released and it is difficult to know if FTTN for Non HFC in Chirnside Park is actually being planned for.

The reason why I believe that FTTN is not being planned for the Non HFC areas of Chirnside Park is that the Govt website https://www.mybroadband.communications.gov.au/ shows that HFC is available for addresses in the Non HFC part of Chirnside Park.
Therefore it is reasonable to assume that the Dept of Communications actually believes that all of Chirnside Park is covered by HFC when the reality is that approx 800 homes do not have access to HFC.

Based on this, I believe that the Govt and NBN do not have any plan in place for many addresses in Chirnside Park Vic.