Fire services are investigating the cause of Christchurch house fire.

Three fire appliances were called to the blaze on Victors Road at around 9.30 this morning.

Wigram Station officer Peter McGrail says flames were coming out all the windows when they arrived on scene.

He says a house occupant opened a bedroom door, discovering the fire blazing inside, but they don't know how it was caused.

"Heat and smoke damage throughout the whole house. TV's and other personal items have been damaged."

The Hoon Hay family are trying to salvage what they can from the wreck.

A young man outside the property says his mum, brother, sister and two cousins were inside at the time.

He says he's shocked his family has lost their house, but he's relieved everyone is okay.

"We have options. It's just starting from the bottom again. But that's what family is for, to work together."

He's hoping they can salvage some belongings from the charred property.

"My dad's going now to see if he can scoop anything up. He's going to grab what he can grab."

He says he got a call from his brother in tears telling him their house was on fire.

He believes it may have started in a bedroom.

"This is out there for other families to check everything before you go to sleep, because you might wake up and have no house."

Christchurch Hospital says they're looking after four people from the property, who are all in stable condition.