A Christchurch man selflessly dashed into his neighbour's fire-engulfed home to make a dramatic rescue last night.

The fire occurred at a Barbadoes St property, near Bealey Ave, about 6.20pm.

Lucas Lormans and his wife Pam, who live next door, were the first to notice the smoke.

"Pam was cooking in the kitchen and she said 'there's all this smoke, what's the deal with that?' I went to go and have a closer look, as soon as I walked out the door it was billowing," Lormans said.

"I sprinted across to next door and yelled out as I was running 'call the fire brigade"'.

When Lormans entered the blazing house he found his neighbour sitting on the couch in the lounge.

The kitchen was flooded by flames and the smoke was "cloaking up a third of the room [lounge]", he said.

Lormans said he was yelling the injured man's name as he tried to lift him. His eyes opened but his body was limp, he said.

All the while the flames were "roaring" and the heat was overpowering.

"I leaned forward and grabbed him with one arm. He was dead weight … I realised I was not going to get him and yelled for help," Lormans said.

Fortunately, he managed to attract the attention of a passerby.

"Another random dude walking along the road stopped and the two of us grabbed him and pulled him out onto the driveway and left him sitting there in front of the house – it was fully engulfed by that stage.

"It all happened so quick. It would've only been about another 30 seconds before he was in flames himself."

Lucas and the passerby decided to move the man closer to the road for safety.

Shortly after the fire "exploded", bursting the windows.

A St John spokesman said a male patient was taken to Christchurch Hospital Emergency Department with burns and smoke inhalation.

"He was in a serious condition," he said.

Pam Lormans said she was "really proud" of her husband, who suffered some smoke inhalation during the ordeal.

"I'm always proud, he's my husband, he's a really good dad. I'm proud he put someone else's life in front of his own."

Lucas Lormans said he did not think before running to the burning house.

"It was just instinct or whatever. You just don't even think about it, you do it. I'd hope someone would do the same for me," he said.

Christchurch senior station officer Nigel Brook said the fire was not being treated as suspicious.

A fire safety officer is investigating the cause of the fire, which is believed to have started in the kitchen.

Brook said there were smoke alarms in the house but he was not sure if they were working.

He commended the brave actions of Lucas.

"When we got here there was flames all out of the windows. He [the neighbour] actually did a great job."

- © Fairfax NZ News