The Sir Henry Floyd Grammar School in Aylesbury will officially opens its new building this week.
Named after former Chair of Governors John Lawrence, the Lawrence Building features new classrooms and an enlarged study area for Sixth Form students.
Headteacher Stephen Box said: “We are looking forward to having another modern feature as part of the building which ensures that students will have a high-quality experience with us.”
The new building will feature nine new classrooms, a study area for Sixth Form students and an IT suite.
John Lawrence was chair of Governors at the school from 2011 to 2016.
Mr Box said: “John was a significant driver in the school’s rapid improvement both in terms of exam results and the relationship and trust the school built with parents.”
Mr Box added the school looked forward to seeing many benefits from the new facility.
He said: “As of September we will be able to admit 180 in each year whereas previously it was 150 per year.
“That works out at about 200 extra students across the year groups.
“We can also admit more Sixth Form students from September because they will have additional study space.”
The new building has been funded by the Department for Education, Bucks County Council and the school, with additional assistance from parents, the William Harding Trust, and caterers Alliance in Partnership.