Aspiring home owners in south-west Sydney are weeks away from losing their land to developers, as they continue to wait for a sewerage connection.

The owners at the Torana estate in Austral were sold on a dream block of land, where prices began at about $600,000. 

But, three years on, construction has yet to start.

Darlene Dixon said purchasing the land had turned into a nightmare.

"Every day it makes me sick in the stomach that this is the worst decision I ever made," she said.

The estate has started to take shape; the streets are named, light posts installed, and the wi-fi is working.  

Ms Dixon is just one of 35 owners who may lose their property in weeks.

She purchased the land in September 2020, with the goal of building a "dream home" with her two children. 

Land owners signed a three-year sunset clause with developer Kitron.

The developer can choose to refund the deposits and re-sell the land, an outcome that would devastate families who have already spent thousands in contractor fees due to the delays.

Kitron did not respond to ABC requests for comment.

NSW Opposition leader Chris Minns said it is time for the problem to be resolved.

"I feel terrible for these families who have put their life savings into the family home. We need to get this infrastructure into these communities so these families can get on with their lives," Mr Minns said.

"We're going to raise it in parliament we're going to shine the spotlight on this issue."

Buyers need to have the land registered in their name with NSW Land Registry Services to get permission to build on it, after all the utilities like water, sewerage, gas, and electricity have been connected.

In a statement, Sydney Water said a solution is likely by early 2023.

"Sydney Water has been actively working with the developer and its Water Servicing Coordinator (WSC) to fast track a solution for land purchasers.

"A proposed interim solution was submitted by the developer's WSC to Sydney Water. Some design issues have been identified and need to be rectified."

Land owner Lisa Hodge said the extended time frame has made it hard to apply for home building grants and her plea to extend her development clause has been denied.

"They cannot issue an extension because it wouldn't be in the best interest for them," she said.

"I should be sitting in my house, but instead I am now faced with having to go and rent. It's just killing me emotionally, I don't even know how much longer it's going to go on.

"I don't even know how much it will cost to build, I don't even know if I can afford to build my house."