The repair bill for the backlog of school maintenance in Northern Ireland currently stands at £400m - although another £400m is needed to keep the under-pressure education system going as it is.
The stark figure was presented to the Stormont education committee yesterday by the Education Authority (EA).
The committee heard that the £400m maintenance cost to ensure all schools operate at a modern standard equates to 1,600 schemes yet to be completed.
SDLP committee member Justin McNulty described the figure "astonishing", particularly given the EA has estimated that £90m of the total maintenance bill is required for "critical" works.
Speaking afterwards, Mr McNulty said urgent action is needed to address the issue.
"Our school estate must be fit for purpose. Children deserve to be taught in a modern, safe and appropriate environment," he said. "Teachers and staff deserve to work in a safe environment with the resources they need."
The development comes after Education Minister Peter Weir recently warned that schools here require an extra £400m per year to address a teachers' pay dispute, improve special needs provision, bolster schools' operating budgets and finance a planned childcare strategy.
This represents a 20% rise on the current annual education budget of around £2bn - 99% of which is spent directly in schools, according to the EA.
Its chief executive Sara Long echoed Mr Weir's financial assessment, insisting the extra investment is required to run the sector at a basic level.
"The £400m is in order to continue the system as it is," she said.
However, she added that for radical reform of the education system "key policy changes are needed" in areas such as the Department of Education's home-to-school transport scheme, the 14 to 19-year-olds strategy and early years intervention.
Committee chairperson Chris Lyttle expressed surprise at the £400m maintenance figure, adding it is the same amount education requires annually overall.
"Can I ask how this (school maintenance backlog) impacts schools?" the Alliance MLA said.
An EA official replied that it can affect schools in various ways, such as electrical works to outdated heating schemes.
The committee also heard that schools here will exceed their budgets by £30m this year.
The EA chief insisted principals are working under an "intolerable strain" to operate their schools amid increasing demands and fewer resources, particularly meeting the requirements of children with special education needs.
"School deficits continue to rise despite the actions taken by school leaders," Ms Long told the committee.
Seamus Wade, EA's assistant director of financial services, stressed that it had been their "absolute priority" to avoid cuts at school levels.
However, he said the financial situation is not improving for schools, insisting the problem could not be resolved in a year.
Ms Long also told the committee the EA had "continued to drive forward" as best it could during Stormont's three-year absence but action was now required.
In response Mr Lyttle said there was a need for political leadership going forward.