The event takes place at Mid Sussex Voluntary Action, The Cherry Tree Centre in Fairfield Road on Wednesday, July 20.
Doors will be open from 3.30pm to 7.30pm and there is no need to book.
A West Sussex County Council spokesperson said: “The secondary school is part of a new ‘all-through’ primary and secondary school for Northern Arc, which will be run by the University of Brighton Academy Trust.
"The secondary school includes all the facilities recommended by the Department for Education for a school of this size, including a dedicated Special Support Centre, with strong sustainability credentials, in line with the West Sussex County Council Climate Change Strategy 2020-2030.
"As a demonstration of this Council’s Climate Change Pledge, the building aims to achieve Passivhaus certification, reflecting ultra-low carbon emissions in operation, with an acute focus on energy efficiency, insulation, on-site energy generation and no use of fossil fuels in the running of the building.”
West Sussex County Council said it is preparing to submit a reserved matters planning application in August.
At the event people will be able to see the plans on display and ask questions, as well as meet the County Council’s Project Team who will explain the plans.