An Auckland school for some of our most vulnerable children is crumbling, and any hopes for a rebuild have just been dashed by the government's moves to halt school property developments.

Twenty years of hoping for better facilities - such as buildings that aren't riddled with mould - have been dealt another blow at Sommerville School.

Sewage bubbling out of floors, mushrooms growing above windows, prison-like outdoor spaces.

This is the reality for the Sommerville special school, specifically for those with disabilities, in east Auckland.

The school's promised rebuild has never eventuated. Instead, its environment just gets worse as its board hesitates to spend money on buildings that may just be demolished.

But any changes for the better are on hold as the government announces an inquiry into "unrealistic and unaffordable" school property works.

In today's podcast, Sommerville School principal Belinda Johnston and deputy principal Corey Busfield give The Detail's Tom Kitchin a tour of their crumbling environment.

A room partly used as a music therapy space has mould and smells awful.

"Just under the window, the mould has actually started eating into the plaster," says Busfield. "My chest gets quite tight once I've been in here for a little while."

Next is the asbestos-ridden hall.

"There were some leaks in the roof so one of our projects was to get it re-roofed over the holidays,'' Busfield says.

"Now they've done half of the job and started finding asbestos sheeting up in the apex, so they have stopped work altogether... at the apex at the top there are holes for ventilation normally - they've now taped those up for safety, just in case any asbestos fibres were to float down."

And the staff lunchroom where mushrooms are on the menu - and not in a good way.

"These are black mushrooms growing out of the top of the window right up by the ceiling," says Johnston. "They are the most disgusting things you've ever seen in your life on the inside of the building and there's a musty horrible smell in here."

These types of problems have been going on for years and nothing has happened, despite promises, designs and plans.

"We've got families who came to this school more than 16 years ago with their child and were told by the previous principal, 'don't worry about the crumbling buildings, because the Ministry of Education has promised us a brand new school'," Johnston says.

One of these promises was in 2018, when the Labour-NZ First coalition government announced Sommerville would get a $17 million rebuild. …

Go to this episode on rnz.co.nz for more details