Parents have expressed “anger” and “outrage” over a blunder which has left Dargavel Primary School facing severe capacity worries.
They have outlined “major concerns” about potential overcrowding at the facility in Arrochar Drive, Bishopton, and the agreed use of six modular classrooms as an interim fix.
The classrooms were approved as a short term fix and come at the cost of millions of pounds.
A review has been ordered in the search for answers over botched sums and council chiefs have embarked upon a quest for a permanent solution.
The school’s parent council issued a stinging statement, which was circulated at a special meeting of the education board on Monday morning.
It said they had “no confidence” that those responsible for the botched calculations will get things right going forward.
The saga emerged after analysis suggested space could be needed for as many as 1,100 pupils in the catchment in the future – a figure double the school’s preferred maximum of 548.
The roll could soar to around 600 to 620 by August 2023 and even further to between 685 and 705 the year after that.
Previous sums predicted the register would not exceed 430.
Alan Kelly, chair of Dargavel Primary School parent council, said: “There is outrage, anger and disappointment directed at Renfrewshire Council from the parent council, parents and wider community regarding this complete failure of the council to plan school provision properly.
“We have major concerns that overcrowding at the school, and accommodating children in modular buildings will negatively impact the learning experience of the children.
“There is no confidence that those people within Renfrewshire Council responsible for this terrible mistake are in fact capable of getting anything right moving forward.”
He said members of the community had warned the council that projections for the school roll were “woefully inadequate”.
Mr Kelly added: “Why did Renfrewshire Council proceed when there were so many opposing voices?
Councillor Emma Rodden, SNP education convener, said that while the school is not yet at a capacity, it would “become full” next year without action.
With that in mind, she added: “We must address this decisively and quickly.
“This has occurred despite concerns raised by parents previously and I understand how frustrated and let down families will be feeling.
“Again, we are deeply sorry.”
Steven Quinn, the council’s director of children’s services, took the opportunity at the meeting to reiterate his apologies to those affected by the situation.
He said: “Can I just take a further opportunity on behalf of council to apologise to the Dargavel school community and especially the children at Dargavel Primary School, who do and who will attend the school in the future.
“We’re absolutely determined to work with you, the members, and indeed the school community as we develop that interim solution through to the new children coming in, in August, and indeed to a permanent solution of what the school environment will look like for all of the children in Dargavel who will attend now and in the future.”
A report will be put before elected members in the early part of next year.