A mechanical digger has begun tearing down the old St Peter Port School.
The Les Ozouets campus was built in the 1960s.
Specialist contractors have been removing asbestos, and now a mechanical digger is being used to break the building down.
The site should be levelled by mid-August, to allow a new Guernsey Institute to be constructed.
Institute Head Tracey McClean says the new campus will offer opportunity to many post 16 students:
"In three years time hopefully we will be moving into a brand-new building, so it will mean that we can increase our provision and opportunities on the island.
There's nothing like learning in the classroom and being with a group of peers and sharing ideas."

Temporary traffic lights removed from key St Peter Port route sooner than expected
New car for Guernsey's Meals on Wheels fleet
Major power cut switches off most of Alderney
Perfect evening for Guernsey's 2026 Air Display
The Red Arrows pull out of performing over Guernsey
Guernsey's Ladies' Pool reopens after pollution incident
Passengers at Guernsey Airport told to expect some flight disruption
Guernsey flights impacted by UK air traffic control issue