A £10m housing and care development on the site of former Denbigh Grammar School has been given the go-ahead by Denbighshire councillors.
Conservation group Cadw had suggested saving some of the buildings from demolition.
But a report to the planning committee said the condition of the buildings meant they were not viable.
The school was built in 1903 but closed in 1983, later becoming a youth club and education training centre.
In February, the council approved housing association plans to build 70 flats on the site with care facilities.
Wednesday's vote paves the way for the clearance of the site.