Often cramped, dull and without a properly functioning air conditioner - if there was one at all - they don't tend to bring back the best memories.

Yet, NSW Labor claim the state coalition government is continuing to funnel millions per year into those types of facilities.

They claim the government has spent $275 million since coming into power in March 2011, signalling a 1,460 per cent increase.

Investment in new, permanent rooms would have been a smarter decision according to the opposition, although Upper Hunter MP Michael Johnsen has a different perspective on the topic.

"The funding provided by the NSW Liberals and Nationals Government is targeted at building new, permanent classrooms and high quality facilities," he said.

"The department utilises demountables to remain responsive to changing enrolment needs in schools across the state.

"All new and upgraded schools receive air conditioning and all demountable classrooms are also air-conditioned."

Shadow Minister for Education, Prue Car, agrees there are ever evolving requirements when it comes to the amount of children in schools.

However, she states the acting government has mishandled the situation and is to blame for the situation.

"New schools are full on day one because of this Government's failure to manage growth in NSW.

"This is an overcrowding crisis of the government's own making."

Mr Johnsen said that while not every demountable will removed as part of the $6.7 billion project they have committed to, which will take place over the next four years, some local schools will be getting upgrades.

Muswellbrook South Public School, where he attended earlier this year with then-education minister Rob Stokes, is one of the institutions in line for improvements.

He said planning was already underway, with the school currently engaging in designs for a number issues including the potential for a new drop-off and pick-up zone.