Principals are frustrated and worried by a decision to halt 100 school building projects.
The Education Ministry has put the projects on hold as part of a move it says will save $2 billion.
The value for money review considered 352 projects at 305 schools with a combined estimated cost of $4.6b.
It decided 110 projects would go ahead with changes such as removing non-essential aspects of the build or using modular or off-the-shelf rather than bespoke designs.
Among the halted jobs were two new classroom blocks for Auckland's Beach Haven School.
The school's principal Stephanie Thompson said the news was like getting coals for Christmas.
"Beach Haven just keeps getting put aside when these things happen. It's just disappointing," she said.
"It's like waking up on Christmas morning hoping for something really nice and then getting a piece of coal."
Thompson said she was grateful the school recently received temporary classrooms, but it had no spare classroom space and its staffroom could not fit all its staff.
She understood other schools had classrooms in bad condition and their need was greater, but the school had been "so close" to starting construction.
"We were waiting for it to be signed off so we could get it all priced up and with the anticipation that very soon we could start building," she said.
"We were looking at two and three-storey options so it was quite a significant deal."
Thompson said the school had been patient but she now wished things had moved faster.
'Hugely problematic'
Another school affected by the ministry's decision was Burnside High School in Christchurch where a redevelopment job has been halted.
The school's principal Scott Haines said that was "hugely problematic" though he was not sure when RNZ spoke to him which of school's projects was affected.
He said the school had two classroom blocks closed due to earthquake risk, other classrooms in urgent need of replacement, and the school was also part of the Christchurch schools' rebuild project.
"We've got some major property headwinds. In fact, the single biggest issue at Burnside High School, right now is our property provision," he said.
"Students are in spaces that that I'm not proud of at the moment. The very basic minimum requirement is that those teaching spaces should be warm and dry and in a number of those classrooms they are lacking either one or both of those things. And of course I and J, the two blocks that we've just lost due to seismic issues, were two of our newest teaching blocks in the school."
"I feel like we've gone backwards and we will go further backwards if funding is lost."
Ashburton College principal Simon Coleman said the first he heard that a school building project had been deferred was when a local newspaper called him seeking reaction.
"We didn't get anything formally and I was a bit surprised at that... I thought we would have had a heads up from the ministry."
Coleman said the college had several building projects on the go and he understood the roll growth part of the programme had been deferred and would be considered as a separate project.
"I'm hoping the continued redevelopment of a 44-classroom block will continue, but that might not be until the next Budget and we are waiting to get clarity on that process."
The school had been waiting on a rebuild for the last decade.
"I am worried about the pure state of the classrooms, they are just not satisfactory for anyone to be either teaching in or for students to be learning in.
"They are well over 60 years old and we have waited 10 years where all the work stopped on those buildings because we were getting a completely rebuilt school."
Many of the school's classrooms were very dilapidated, had poor heating and cooling and leaked during wet weather and he was unsure how much longer the school would have to wait for answers.
It was particularly disappointing, he said as Prime Minister Christopher Luxon visited last month and had seen first hand the state of the school buildings.
"I do believe that there needs to be some immediate action around the health and safety and welfare of people that are working and learning in some of these spaces."
He said the school was not interested in bespoke buildings - they just wanted fit for purpose classrooms.
Coleman hoped to have "open, honest and timely conversations" with the Education Ministry around the next steps, so they could work together to find a solution.
Relief for Southland school
An Invercargill school says it is "ecstatic" its building project is going ahead, albeit with changes to save $2 million.
James Hargest College principal Mike Newell said the school's long limbo would end next week.
"We're meeting with our design team again on Monday to start seeing where we can cut some costs."
The school needed 14 new classrooms.
Newell told RNZ in February how ceilings had collapsed on children, and the special needs unit leaked like "a wall of water".
"We were ecstatic when we got the news that our project was going ahead," he said on Friday.
"And it wasn't a surprise to us with the caveat that we need to save two million" on the $24m project.
They had already been told that simply cutting out a big window and having a more even roof would save $500,000.
"If it's things like that then we're OK with that," Newell said.
He would make sure no cuts ate into functionality or durability. "We know what's happened previously when people have tried to do cheap jobs."
Meanwhile, no changes were made to 142 projects but some of those were only in the design and planning stage and would need further approval before they could proceed to construction or design.
Most of the projects considered by the review were driven by roll growth at schools (234) and 118 were related to the poor condition of existing buildings.
The ministry said the review of ministry-led building projects considered cost efficiencies and the need and timing of projects.
"The cost to build a classroom has increased significantly over the past few years. We need to bring costs down and make sure we're achieving good value across all projects in our programme," it said.
"With such high demand for new school property across the country, the more cost efficiencies we can achieve on individual projects, the more we can deliver across the country to the benefit of all ākonga/students."
It said some of the projects needed a "deep dive" while others needed a light touch review depending on the stage they were at.
"Of the 352 projects, 252 will proceed with planning, design or construction activities as planned or with changes. Projects funded for planning and design will need to seek further funding approval to proceed to the next stage. For most projects this will mean being prioritised for investment through the Budget 25 process," the ministry said.
"One hundred projects will not proceed at this time. These projects will be reconsidered for investment as part of the Budget 25 process. One hundred and ten projects are proceeding with changes. Of them, 62 are growth projects and 48 condition projects. Changes made include removing non-essential scope and/or changing the delivery solution to a simpler, repeatable, or modular solution."
A list of the projects showed the deferred projects included a new secondary school in Drury, and new primary schools in New Lynn/Avondale, Cambridge, Omokoroa near Tauranga, Tamaoho in Auckland, and Te Kauwhata in Waikato.
Other projects that were deferred included roll growth building at Auckland schools Baverstock Oaks and Birkenhead, and at Ashburton College and Clyde School.
Redevelopment at Central Hawke's Bay College and Gisborne Boys' High School would not proceed.
Additional reporting by Phil Pennington.