Police and fire investigators have finished their scene examination of the Christchurch "House of Horrors" after a blaze ripped through the property.
But they have not yet released details on how the suspected arson started.
The bodies of Tisha Lowry, 28, and Rebecca Sarah Somerville, 35, were found underneath one of the two semi-detached homes in the block in suburban Wainoni earlier this month.
Mrs Somerville's husband, Jason Somerville, 33, who lived with his wife at the property, has been charged with murdering both women.
Ms Lowry lived a couple of doors along from the property when she went missing a year ago.
The property sustained major damage in the fire.
The Christchurch City Council was this afternoon boarding up the house, a Christchurch police spokesman said.
Police and fire safety investigators had finished their examinations of the house, but had not yet released their findings.
No suspects had been identified, he said.
Half the building was well alight when firefighters arrived about 10pm.
The former state houses have been unoccupied since the bodies were found.
Christchurch City Council is looking at buying the houses and turning the site into a memorial park.