At 11.57pm on December 10, Fire and Rescue NSW crews from 392 Muswellbrook and 208 Aberdeen, along with Hunter Valley Police District, attended a house fire in Shaw Crescent, faced with the possibility that a man was trapped inside.

On arrival, they found the home fully alight.

Crews quickly got to work on the fire, however powerlines to the premises had been damaged and "live" powerlines were positioned across the driveway.

Ausgrid was called to the site to isolate power to the lines and ensure the safety of the firefighters.

After confirming the occupant had self-evacuated, medical assistance was provided while awaiting the arrival of NSW Ambulance paramedics.

He was transferred to Muswellbrook District Hospital for observation.

An investigation into the cause of the blaze is continuing.

"The man was awoken by working smoke alarms - and managed to get out of the house safely," a 392 spokesperson said.

"We were on the scene for approximately two hours.

"But, the house was totally destroyed, while the place next door suffered heat damage as a result of the fire."

According to NSW Fire and Rescue, the risk of fatality is halved when there is a working smoke alarm in a home.

For more information on the law surrounding smoke alarms and tips on maintenance, visit NSW Fire and Rescue's website.