Wynyard, Castle Hill and St Leonards are among 44 suburbs and towns in NSW where National Broadband Network construction work will be rolled out next year.
NBN Co updated its $42 billion rollout contruction plan on Wednesday, announcing that by September 2016, work will begin to add 158,000 homes and businesses in NSW to the network.
It takes one year for construction work to be completed. Once a suburb is connected, its residents and businesses have about 18 months to swap to NBN-enabled phone and internet deals before the old copper connections are switched off.
"Our job is to ensure that all Australians can have access to very fast broadband as soon and as cost-effectively as possible," said NBN Co spokesman Darren Rudd.
"The addition of a further 158,000 homes and businesses to the NSW construction schedule demonstrates the continued momentum of the rollout."
In Sydney, construction work will begin in Castle Hill, City South, Circular Quay, Wynyard and St Leonards, covering 26,660 premises.
Work will also begin in Erina, Bathurst, Albury, Coonabarabran, Jindabyne and Gundagai.
 
The announcement comes as the Australian Bureau of Statistics revealed average broadband downloads jumped 33 per cent in the year to December.
"Our appetite for smart devices and online content continues to grow at an exponential rate. The NBN is designed to provide a fast and reliable broadband network to help Aussie households keep up with their insatiable demand for connectivity," said NBN Co's principal technology officer Tony Cross.
The Australian Competition and Consumer Commission urged the public to understand how the NBN rollout in their area will affect their phone and internet services.
The watchdog said Telstra will soon be disconnecting telephone and internet services in NBN-connected areas, and some consumers were at risk of being left behind.
"Connecting to the NBN is not automatic and you will need to take action ahead of disconnection date," said ACCC Commissioner Cristina Cifuentes.
"If you want to keep your landline phone and internet services, you should place an order for an NBN service by the disconnection date for your region or your current services will eventually be permanently disconnected."
The quarterly construction plan provides an indicative schedule that includes work already underway or in plan to commence before the end of September 2016 and in total covers more than 890,000 NSW homes and businesses.
In March, about 8800 homes and businesses in Blacktown, Homebush and Riverstone joined properties in Penrith and had existing landline services replaced by the NBN.
NBN Co said the expansion of the rollout reflected the company's new, flexible multi-technology approach, adding that it was an important step towards reaching its goal of connecting 8 million premises by 2020.
The NBN Co website offers a "Check Your Address" function, allowing users to find out if the NBN is available at their home or business.
NBN MYTHS BUSTED
1. "It's just for broadband": The NBN is for both internet and telephone services. So everyone using a fixed-line copper telephone line must move to the NBN to avoid disconnection.
2. "The transfer is automatic": The move to an NBN-enabled service is not automatic. Customers must contact their internet and telephone service provider and organise the switch to an NBN plan.
3. "It's just for people in rural and regional Australia": The NBN rollout began in regional Australia, but it will spread to all cities. NBN Co aims to connect 8 million homes by 2020.
4. "NBN plans are going to rip us off": Internet or telephone services providers set the prices which can then be easily compared online. NBN Co says consumers are likely to get more services for the same price.
