Today, fire investigators have been at the houses, owned by Bryce and Kate Jenkins, to work out what caused the blaze.
Fire investigator Mark Thomas said he was treating it as accidental.
This morning he told the Herald that he had a theory on how the fire started, but wanted to speak to the guests - who he understood were from Malaysia - to get their accounts of what happened.
Thomas went to visit the people who escaped the fire in hospital late this morning.
He said the guests had tried to put out the fire, and their efforts had alerted neighbours.
Kate Jenkins told Fairfax that she was "absolutely grieving" today for her property that was listed on holiday rental website Airbnb.
The large wooden house with spectacular beach views was listed on Airbnb as suitable for groups of up to eight people. It cost $229 per night to rent. The listing has since been removed.
Christchurch fire spokesman Riwai Grace said crews arrived at 8.41pm to find the property "well involved" in fire.
Five fire crews attended as well as a standby crew waiting at the bottom of the hill, which has very narrow access. Police cordons were set up in the road.
A local resident who lives on the Esplanade below the house said she heard the volunteer fire sirens sounding and looked up the hill to see "a real inferno".
It was not clear from that distance which house was ablaze but it appeared to be an architecturally designed, angular home, she said.
"It was fully in flames."
A neighbour two doors down from the house arrived home just after the fire was put out, but said smoke was still thick in the air.
"It's very scary. It's a wooden house so it went up in flames in half an hour or so," the neighbour said.
Tim Grafton, chief executive of the New Zealand Insurance Council, said if people are renting out their entire house as an AirBnB business and not living there, then they should talk to their insurer at set up time.
"If you have a home policy and you are renting a room out from time to time, you'll normally be automatically be covered for any accidental damage caused by guests in your home - including Airbnb guests," he said.
"While you don't normally need different cover-you'll need to make sure that you're meeting your normal policy conditions, including letting your insurer know if you are not living in the home. Damage caused by paying guests is often subject to an extra excess, on top of your standard excess."