NSW Labor's environment spokesperson has backed Brandy Hill residents who say the NSW Government needs to order a reassessment of the quarry's impact on the koala habitat area before a final decision is made on the Brandy Hill Quarry expansion.

"It's getting more and more clear after the bushfires that we need to be proactive in terms of protecting the koala habitat we've got left, rather than reactive when that habitat is threatened, as it is with this quarry expansion proposal," Brandy Hill resident Chantal Redman said.

Building materials company Hanson has applied to increase production at its Brandy Hill Quarry from 700,000 tonnes to 1.5 million tonnes of material per year. An assessment report prepared for the company found the expansion will "result in the clearance of habitat critical to the survival" of koalas.

In a response to concerns in 2019 the company said it was "confident" the expansion project "would not result in significant impacts to these species" because "predicted impacts" will be offset by the company retaining koala habitat at a location outside the Hunter region.

But Mrs Redman, Ms Washington and Hunter-based Veterinarians for Climate Action member Amy Simon said the destruction of millions of hectares of bush to fires, and particularly koala habitat in northern NSW, means governments have to reconsider how to protect remaining areas.

On Monday Federal Environment Minister Sussan Ley said koalas could soon be listed as endangered in parts of Australia. Early assessments show an estimated 30 per cent of koala habitat has been lost in northern NSW alone.

Mrs Redman said heartbreaking images of dead and badly injured koalas show why it is "even more important to protect the koala habitat we have left".

"I was watching footage of burnt koalas with their ears singed, noses and foot pads burnt. They were just looking at the people helping them. They don't have a voice. We have to be their voice.

"We do have a healthy population of koalas living here. It's only a small pocket of koala habitat, but areas like this are vital," Mrs Redman said.

A spokesperson for Port Stephens Koalas, which has cared for burnt and injured koalas from outside the Hunter since the start of the fire season, said the group is currently caring for 25 koalas and is expecting another four fire victims from Taree on Wednesday.

Residents living around the Brandy Hill Quarry have images of koalas walking across their properties, or sitting in trees on the quarry site, to prove clearance of the nearly 50 hectares will have a direct impact on individual koalas, as well as be a threat to the species.

Mrs Redman said Hanson's proposal to offset the koala habitat clearance by retaining a habitat area outside the Hunter region must be reconsidered.

"Offsets? Where? What offset land suitable for koalas have we got left? Why offset it somewhere else when there is a koala habitat here, and koalas?" she said.

Ms Simon, a Maitland area veterinarian, also questions offsets as a way to ensure koalas' future.

"I don't know why people think we can just displace wildlife without consequences. Koala numbers are just shrinking and shrinking. They're doing the best they can to maintain their populations and social structures, but without the habitats to live in they're struggling, and now we've lost so much because of the fires," Ms Simon said.

"There's so much we don't understand about koalas, and these little pockets of space that are left are vitally important," she said.

"There needs to be another assessment of that proposal. The residents have every right to be worried because you can't presume to just relocate the koalas and think that everything will be okay."

Ms Washington said the Department of Planning had already expressed serious concerns about the accuracy of information in Hanson's submission for the expansion, and the community had been voicing concerns for a long time.

"With the bushfire crisis, survival of the koala has been brought into sharper focus, and it has just got much more difficult," Ms Washington said.

"We must be extra vigilant with these kind of proposals otherwise koalas will become extinct. That is what is at stake. We can't pretend that bulldozing koala habitat doesn't have an effect.

"It's pushing koalas one step closer to extinction, and after the fires, we just can't afford any more habitat loss."

The Department of Planning is currently assessing community and government submissions on the proposal and Hanson's responses to concerns raised.

A report by environmental consultants Biosis Pty Ltd said the loss of nearly 50 hectares of koala habitat at Brandy Hill is "likely to be significant to the national population... given the disjunct populations across the nation".

"Most populations in NSW now survive in fragmented and isolated habitat and many of the areas in which koalas are most abundant are subject to intense development pressures such as agriculture and urban expansion," the report said.

A spokesperson for Hanson acknowledged the devastating impact the bushfires.

"As part of our operations, areas of native vegetation will be retained within land owned by Hanson to the north east, north west and west of the development areas, which contain habitat opportunities for koalas similar to that within the quarry site," the spokesperson said.

"Additionally, land close by to the property is the subject of two separate BioBanking Agreements and have been secured for biodiversity conservation.

"Under the terms of these BioBanking Agreements, management measures will be undertaken which improve or maintain the condition of native vegetation to support the koala habitat."

The company said Brandy Hill Quarry is of "strategic importance to satisfy growing demand from the construction industry in Newcastle and Hunter Region as well as in the Greater Sydney Region".

"There are limited hard rock resources available between Newcastle and Sydney, and the Brandy Hill Quarry meets growing demand that would otherwise need to be met from further away, which would increase the cost of infrastructure, commercial and residential development."