The present school hall is crowded by current student numbers of about 600.

Enrollments at the school have been increasing since 2014 when Mt Carmel's high school closed, leaving Yass High as the only local option for secondary education.

The ACT government has also tightened rules on enrolling non-ACT residents in its public schools, introduced last January.

Labor candidate for Goulburn Dr Ursula Stephens announced the party's commitment last Friday, recognising the Yass Valley's growing population, predicted to reach 23,400 by 2036.

On Monday, Liberal candidate for Goulburn Wendy Tuckerman matched Labor's pledge, citing the hall's benefit to students, staff and "local groups outside of school hours".

However, members of the community are asking why the NSW Government has waited until now to put forward the funding.

The school's teachers and P&C have been advocating for new facilities since the 2012 fire at Yass High.

At that time, insurance money rebuilt the lost buildings, but there was a push for additional funding for a hall, which students had already outgrown, and other teaching facilities, former P&C vice president (2014-15) Michael Pilbrow said.

Mr Pilbrow said a school master plan, including a new hall, was created at that time.

The federal Labor government approved funding in 2013 for up to $700,000 to build the Yass High School Community Trade Training Centre. However, no funding was ever committed to building the hall by NSW Labor or the NSW Liberal-Nationals government.

Present Yass High P&C president Michelle Thornely said the school would welcome a multi-purpose hall.

The new hall will be built on council land, with the school car park cited as an option. Yass Valley mayor Rowena Abbey said the council had been in discussions with the school and NSW Department of Education "for some time" and that it was "fantastic" to get the funding to make the build happen.

The funding relies on either major party getting elected on March 23.