The head of a Bushey secondary school earmarked for expansion has insisted its communal areas must be improved before it takes on more pupils.
Terry James, the principal of Queens’ School, said it was already the largest in Hertfordshire and aspects of the school such as halls and corridors needed investment.
He also disputed education officials’ estimate the improvement works would cost £7 million and said the school was seeking its own quote for the works.
Mr James' comments come as the Aldenham Road school negotiates with Hertfordshire County Council over plans to start expanding it by 30 pupils a year.
He said: "It needs to be done properly. We are already the biggest school in Hertfordshire and we are already very over-subscribed. There are a lot of parents who what to send their children here but can’t as there is not room and there a shortage of school places, so we understand the authority’s and parents’ view.
"But it needs to be done right. The problem is it is about more than just about classroom space. It is more to do with core space. It is about core facilities such as a new assembly hall, dining hall even wider corridor space.
"We are saying in that in principle we need to expand the core facilities. It is not just simply us saying this is what we want for an extra form of entry."
Queens’ School was originally formed in 1969 out of two separate schools: Bushey Grammar School and Alexandra School, and initially had around 1,000 students.
Today it has 1,700 pupils and receives around 1,400 applications each year for its intake of 265 pupils.
Hertfordshire County Council is currently looking to expand a number of secondary schools across the area to head off a looming admissions shortage.
This week the authority agreed funding to expand to other schools in the area Bushey Meads School, in Bushey, and St Clement Danes, in Chorleywood for a combined cost of around £7.5 million.
Negotiations over Queens’ hit an impasse after the county council initially mooted £1.95 million for the expansion and then balked at the £7 million estimate for improvement works describing it as "excessive".
Mr James said the school had not seen the breakdown of the council’s £7 million estimate but was continuing to negotiate with the authority.
He added: "We have given them a shopping list of what we want and they have costed it at £7 million. We dispute that it would cost £7 million. We are getting our own costing."