The acting principal of a high school where mould was identified last month says everyone was moved from the building "the minute" it was discovered.
Students at Hutt Valley High School have been taking some lessons in the hall and library after "unsafe levels of mould" were identified in a block of classrooms two weeks ago.
The Ministry of Education confirmed eight teaching spaces had been "isolated" and said on Thursday it was still awaiting air testing results to see what further action would be needed.
Hutt Valley High School Acting Principal Denise Johnson said long-term options could include remote learning on a rostered basis.
"At the moment we're in an immediate plan and once all the test results come back we'll be able to make a short-term plan.
"We can't keep going with all the kids in the library and the hall.
"We need to find either immediate nice rooms where these kids can be taught, or we are going to have to do some kind of rostering home."
Johnson denied there had been issues with C Block for a number of years, and said students had been moved from the building "the minute we found mould".
"We got the call at 10 past nine and the classes were empty by 9.30.
"The minute there was mould, there was no one there. We were not aware of mould until we were aware, and then we acted straightaway."
She said the school site was old, with the roof of C Block prone to leaks and had been patched several times.
"Another leak has appeared and that's obviously where the mould has come from. Mould grows where there's a leak."
"Not all mould is bad mould, but black mould in particular – there are two types, one in particular is really bad on the respiratory system, and one that's bad for allergies.
"We've got both types at various places in that block where we have closed down rooms."
Ministry of Education head of infrastructure service Kim Shannon said it had met with the school on Wednesday to discuss next steps.
"The ministry will take on management of the Block C remediation project. As in this case, where health and safety issues arise, funding is available to address these with urgency."
She said the ministry was awaiting the air testing results from Block C and was also carrying out testing in other areas of the school as a precaution.
"All students are currently able to learn on site, including using the hall and library for teaching."
"We recognise this is challenging for some students and staff and thank them for their leadership and commitment to learning."
"At this stage we don't know how many students will be affected, but we will support the school to minimise any impact on students' learning.