Planning Minister Anthony Roberts has announced the government will assume responsibility for three planning proposals which he says could improve the safety for endangered koalas in the Macarthur Region, while also providing much-needed new housing.

"Setting up koala corridors is a key part of our conservation efforts to make sure koalas can safely move around, and these proposals could help secure and implement koala plans identified in the Cumberland Plain Conservation Plan," he said on Wednesday.

Koala corridors are green areas that allow the native marsupials to move between habitats.

The koala population is thriving in the town of Appin and surrounds, according to the Wollondilly Shire Council, and includes some of the only ones in NSW that remain free of disease.

The three proposals are a 876-hectare site in Gilead from Lendlease for 3300 homes and several koala corridors, a 300ha site in Appin from Ingham Property Group (3000 homes, one koala corridor), and a 1284ha site at North Appin from Walker Corporation (12,900 homes and new koala corridors).

While planning proposals usually require local council approval, the state government has taken carriage of the projects citing their potential to deliver housing and environmental benefits.

The government says it will continue to work with councils throughout the approval process.

"Nothing about the assessment process changes including the important need for community consultation," Mr Roberts said.

The plan is part of the NSW government's $2.8 billion package to improve the supply of housing.

Shadow treasurer Daniel Mookhey said Labor will scrutinise the proposals to ensure western Sydney residents have supportive infrastructure.

"We've seen this pattern emerge over the last 12 years where the housing arrives before the schools, before the hospitals, before the police stations, before the fire stations," he said.

"The people of western Sydney are entitled to feel sceptical that nothing is going to change with this government.

"They've had 12 years to deliver housing at the same time as they deliver infrastructure and they failed."

The decision to do away with council-led decision-making is a backflip from the position held by former planning minister Rob Stokes, and was praised by the property developer advocate Urban Taskforce Australia.

"Urban Taskforce has been calling for state-led assessment of major projects for years," its CEO Tom Forrest said.

"These large projects often cross council borders ... councils are ill-equipped to deal with the multitude of regulatory authorities and agencies that have a say on these types of development projects."

Australian Associated Press