The head of Catholic education says integrated schools need more money from the Government, not less as advocated by a teachers' association.
Brother Pat Lynch, chief executive of the Catholic Education Office, said state-integrated schools struggled to keep up with Government-imposed building standards and had been asking for $90 million since 2007.
He said primary schools were required to increase their classroom capacity by 48 per cent in 1998 and secondary schools were required to increase theirs by 24 per cent in 2001.
But because state-integrated schools were already trying to catch up to building codes imposed in the 1980s they have been in a constant state of "catch-up mode".
Another $75 million was required to bring Catholic schools up to state building codes and $90 million was needed for all integrated schools, he said.
Forcing parents to pay higher attendance dues was not an option for many schools, especially during the recession.
The Post Primary Teachers Association believes state-integrated schools are already "unduly privileged" by anomalies in the Private Schools Conditional Integration Act 1975.
At its annual conference next month, the association will be calling for the act to be repealed so no further private schools could integrate and take advantage of access to government funds as well as changes to the Education Act that decides how money is spent on integrated schools.
State-integrated schools have a unique funding structure split between the government and the proprietors of the school that allow them to preserve their "special character".
PPTA president Kate Gainsford said more clarity was needed around what could constitute "special character".
She suggested taxpayers might not be comfortable that in one school, this defining character was about "teaching young people that they are born as lost sinners and can only be reconciled to God the Father by a supernatural work of regenerating grace whereby the Holy Spirit grants faith to receive of the merits of the Lord Jesus Christ".
Brother Lynch said a variety of schools was needed to reflect the increasing cultural diversity of New Zealand society.
A large proportion of new immigrants sought schools with a particular religion or philosophy, he said.
Brother Lynch said Catholic schools encouraged leadership from migrant communities by helping parents become involved with their children's school-ing.
But Mrs Gainsford said the state education system already reflected the diversity of New Zealand communities, with the added advantage of promoting social cohesion.
The PPTA annual conference papers refer to a proposal by England's National Union of Teachers that all schools offer multi-faith studies and do their best to accommodate all religions, as opposed to segregating the faiths in separate schools.