After that Central Demolition will sow the whole area to lawn, and replace the pile and chain fence around it. It should all be done within two weeks.
The job doesn't end at the site, however.
"Our goal is to recycle everything we do," Butcher said.
The Central Demolition base in Feilding has an $800,000 concrete crusher. The building's concrete will be crushed and used as metal on Manawatū roads.
Doors and windows can be reused - where they meet building code. If not their timber and steel framing has other uses.
Recycling everything takes longer, but is cost-neutral overall, Butcher said.
The building was farewelled by Whanganui Iwi on September 4, before demolition began.
It was too vulnerable to future flood damage to keep as it was, Ngā Tāngata Tiaki o Whanganui Trust chairman Gerrard Albert said earlier this month.
It was the base for Whanganui River Settlement negotiations from 1988 to 2017, and before that was a New Zealand Railways bus stop.
"For the immediate future, we will have an open green space next to the awa to tell some stories. Until we decide what use to make of the site, it can be a place for pedestrian traffic to enjoy," Albert said.
"We want to promote Te Awa Tupua there in the interim so that people understand the iwi journey - the river being central to ourselves as the iwi and the community."