The area at Ralph Allen School will be used to exhibit students' work, as well as housing new classrooms, meeting zones and a Snack Shack selling refreshments.
It was launched with an afternoon of performances and demonstrations by pupils, including Year 9 to 11 dance students, examples of textile work, piano music by Hattie Bailey and a Year 11 photographic studio shoot.
There was also a Past, Present and Future display about a future planned project at the school, the proposed applied learning centre.
Head teacher Libby Lee welcomed Year 9 student Simeon Wakely and local artist David Cobley to cut the ribbon, which was made up of photographic film showing negatives of the area.
She said: "Students are already using this exciting new space for art, photography and textiles work, and have given very positive feedback about the new environment."
Mr Cobley is an award-winning portrait and figure painter based in Bath, who has exhibited and worked across the world.
At the launch evening, guests were invited to take part in the Make Your Mark art project, where they made a thumbprint in ink. This will form the basis of a school artwork to be displayed in the new art and photography space.