The multi-purpose gymnasium will border the school hall and the No1 soccer ground, and will house a basketball court, a tennis court, four volleyball courts, a netball court, five badminton courts, an indoor hockey court, and static weights and fitness training areas.
There also will be a mezzanine floor that incorporates a classroom, kitchen and a viewing gallery, and the gym will be available for community use.
The Wellington-based Catholic Schools Board, which owns Chanel College - formerly St Joseph's College for Boys - had earlier earmarked $400,000 for the project and the school also won a grant of $60,000 from the Masterton Licensing Trust and a $30,000 grant from Lands Trust Masterton.
Mr Miles said Archbishop John Dew last year announced a $1 million increase in the board investment and the school and its community had only about $120,000 left to raise before building could begin.
Design elements have been expanded and costs consequently increased from just over $1 million to $1.8 million for the gymnasium, for which plans will be finalised today.
Mr Miles said close to $300,000 had already been raised through the Chanel College Education Funds, the Chanel College Parents, Teachers and Friends Association, and the Gymnasium Building Committee.
He said upcoming fundraising drives included a school gala day and a giant book sale, and the Gymnasium Pledge Funding Committee was to raise funds from former pupils of Chanel College and of St Joseph's College for Boys and St Bride's.
