General Manager of Finance Technology and Commercial Matthew Kenny says Plunket is proposing to sell because the building is under-utilised by Whānau Āwhina Plunket and only offers Well Child Tamariki Ora services one day a week.
He says there are only 11 children in the books.
"If we are going to be here for another 100 years supporting our communities across Aotearoa, we need to keep adapting to remain financially secure," Kenny says.
"Selling under-utilised properties like Cust could assist us in that mission, to ensure our entire operation is delivering equitable services to all pēpī and tamariki."
Some members of the community disagree.
Local historian Bernard Kingsbury says through the years Cust Plunket Society members have done a lot of fundraising in maintaining their group and raising money for the rooms.
Kingsbury says he doesn't want to see a repeat of what happened with the Cust Scout Den. He says the den was donated and went through a national body, but when the building was sold, the money went out of the area.
"It was pretty wrong really...I don't want to see this happen to the Plunket rooms."
The building was fundraised for and has been maintained by the Cust Plunket Society since 1923.
Built by the husbands of community members, construction took place on Saturday mornings under the supervision of local builders Thompson and Reece.
The total cost of the building was 857 dollars, 99 shillings and 2 pence, funded by the Cust community. The foundation stone was laid in August 1957.
Kingsbury says the land was given to the Plunket Society by the Rangiora County Council.
"It would be a shame for the facility that was fundraised by the community...for the proceeds of it to go out of the area. I feel it should be retained for a non-profit organisation here to use."
Kingsbury's view is reflective of many in the community. Members have discussed their concerns on the Cust community’s Facebook page.
A meeting was held last week with Plunket and the Waimakariri District Council to reassure there was high community interest in the intention to sell.