A 14-year-old girl was arrested on Wednesday afternoon by police, following investigations into the deliberately lit fire at Inverell High School which destroyed the industrial arts building.

The fire broke out just before 1.30pm and more than 700 staff and students were evacuated as fire fighters tried to douse the blaze which spread to much of the classrooms block.

Police will allege in court the girl, who is a student at the school, set fire to a tree before the blaze spread to the building, taking hold, causing the ceiling beams and roof to collapse.

Police have confirmed the damage bill from the fire is likely to exceed $200,000.

The 14-year-old girl is facing one count of recklessly cause damage by fire after she was charged on Wednesday night at Inverell Police Station.

The girl was granted conditional bail to appear in Inverell Children's Court in March.

A Department of Education spokesperson will not confirm if the girl has been suspended in the wake of the police charge.

"As the matter is to go before the courts, it is inappropriate for the Department to comment on any disciplinary action the school may take in relation to the juvenile charged," a statement said.

The loss of classrooms in the fire has seen further disruptions to school timetables today, according to the Department with the damage still being assessed by specialists.

"Parents may choose not to send children to school, but should understand that if they wish to send children to school they will be supervised as all staff will be on site," a spokesperson said.

"The process of ordering temporary accommodation has commenced and the Department's Assets team will be working to facilitate prompt installation so practical classes can continue.

"Inverell High School would like to extend its heartfelt appreciation to its staff, parents, members of the community, many schools and local member Adam Marshall that have offered support and good wishes since (Wednesday)."