Plans to bulldoze Hertswood Academy and replace it with housing have been pushed back by one year.
Students at the Thrift Farm Lane, Borehamwood, school, were due to be moved into temporary classrooms at the end of July.
The upper school is due to be merged with the lower school in Cowley Hill, but officials now say they need more time for the “complex” project.
In a statement on the school’s website, headteacher Peter Gillett said he wants to extend the consultation period and instead begin moving students in early 2015.
It said: “The new academy will provide facilities that are at the cutting edge of new developments in education. This is what our community deserves.
“It is important to mention that, throughout the building project, we will continue to raise standards across the academy following our highest ever examination results this year.”
A planning application will be submitted in June 2014 and the academy hopes the new building will be ready in time for the new September 2017 intake.
Money will be raised by selling the upper site, which will help the borough council reach its target of new homes in the area.
The plans form part of Hertsmere Borough Council's core strategy, which will see 2,500 new homes built in Borehamwood.
The Ark Theatre - which cost £2.4m when it was built in 2009 - is also due to be demolished, Mr Gillett says it will be replaced with a “first class’ community theatre.
The statement added: “This rescheduling will also enable us to keep the current community theatre open longer, into 2015, but we are not yet sure of the precise date when it will need to close.
“We are continuing to look at our schedule for vacating the upper site and will be fine tuning exact dates as the planning process develops and will make further announcements in due course.
“In all our discussions to date we have been very clear that we will provide a first class community theatre and community sports facilities as part of the new academy on the lower site.
“We are also looking at ways to minimise the gap between the existing community facilities and the new ones being opened and are working with the council to manage this as effectively as possible.”
Before any formal consultation begins, governors at the academy would like to hear any further comments from members of the public.
To give your views, e-mail firstname.lastname@example.org or write to Hertswood Academy Lower Site, Cowley Hill, Borehamwood.