Federal member for Calare, Andrew Gee has been at Lithgow over the weekend and throughout a series of Facebook videos has updated the electorate on the growing disaster at the foot of the mountains.

He says homes were lost as the fire continued to burn south of the Bells Line of Road on Saturday night.

"I received reports between four to eight (properties) and some of them were sheds. It is heartbreaking that a young family has lost their home just before Christmas," Mr Gee.

"On the positive side, I am relieved a lot more homes were saved than lost."

While NSW Rural Fire Sevice commissioner Shane Fitzsimmons said the threat of more losses would continue.

"There will be a detailed assessment of the potential threat and the likely threat in coming days or weeks to the Blue Mountains region," he said.

"We will be looking at what are the options, what are the fallback lines and at what point do we start implementing very significant strategies to secure protection for an impending threat to the Blue Mountains, particularly the communities along the Great Western Highway.

"A massive effort will be undertaken to try and shore up protection for those communities that are currently under threat and that are likely to come under threat given the forecast conditions over the coming days and weeks."

The 450,000-hectare Gospers Mountain fire, along with the Grose Vallery blaze, were classed as out of control on Sunday and are thought to have destroyed up to 20 homes in total.

However cooler conditions this week are likely to make containment of the mega-blaze partially easier.

The evacuation centre at Lithgow Workies Club slowly filled with residents fleeing homes over the weekend, with NSW Families and Community Services pledging to assist evacuees seeking shelter.