Andersons Bay School principal Pauline Simpson said her school was promised a four-classroom teaching block and hall and that was cut back to two classrooms and a hall with a design change at the 11th hour.
The change would mean the build was back to square one, she said.
A ministry spokesman said it had already spent $750,000 on the project on costs for planning, design, consents and investigation works.
The cutback was a part of a nationwide cost-cutting exercise that meant more than 100 classrooms across 20 schools were placed into limbo by the ministry because of the high cost of delivery, changing roll growth forecasts and reprioritisation of scarce funds.
Ms Simpson said Andersons Bay’s project was at the consent stage and all the planning had been done.
All that was left was the build itself.
"I feel like there is an incredible amount of money being spent on our project to date and there is not a single thing to show for it."
There had been a lack of transparency from the ministry regarding the new classroom builds, she said.
"The ministry should have never made those predictions and promises if they weren’t going to deliver."
The ministry told her its predictions for roll growth at the school had changed because there was capacity for schools in the area to accommodate children in that part of town.
It was very late for the ministry to be changing its mind after consents had been granted, Ms Simpson said.
Schools were facing the brunt of over-promises from the ministry, she said.
"Going forward I think there is some lessons to learn about over-promising because this was a ministry-led project.
"I don’t think this about one or the other government because this model has been like this over the years."
Ministry infrastructure and digital acting leader Stuart Wakefield said work done to date would support the smaller planned development and future roll growth when needed.
Two options for designs would be presented to Andersons Bay in the coming weeks, Mr Wakefield said.
One of the designs was an amendment of the current design, but with the roll growth element removed.
The second option was a design being delivered elsewhere but with specific amendments for Andersons Bay’s needs.
Ms Simpson said she had been told she would receive an update on Friday last week, but it never arrived.
"We don’t really have any say in this process and neither does any other school. We can be frustrated and we can be annoyed but we don’t have any real say."