Students from Peebles High School have returned to the site after the building was damaged by a serious fire two months ago.
Staff from the school and Scottish Borders Council have been working to get the site ready to house lessons.
70 firefighters attended the blaze which ripped through a section of the building causing "significant damage" to art classrooms and a gymnasium.
Following the fire, the school was closed to pupils and staff, and lessons have been taking place at temporary accommodation across Peebles.
A statement released by the council confirmed S4-6 students will return on Monday 3 February with the S1-3 pupils the following day.
Some areas of the site will remain out of bounds but pupils will have lessons in unaffected areas of the main building and temporary classrooms.
A small number of pupils with complex needs will continue to attend lessons at a specialist facility at Galashiels Academy.
Chief Executive of Scottish Borders Council, Tracey Logan, said:“Phasing the return of pupils enables us to manage the preparations effectively.
"One of the most challenging elements is moving from the seven temporary S1-S3 teaching sites in Peebles from the end of the school day on Friday 31 January, hence the additional day to complete this.
“An enormous amount of work has been needed to get us to the position of having all year groups back together in one location – something parents have consistently told us was very important to them.
"To be in a position to do this so quickly is testament to the efforts of all concerned, and the support provided to us by a wide range of partners.
“We do still have work to complete on site, and additional classroom and changing room space will also be opened up in modular buildings later in February, but we are now confident that the return of pupils can take place.”
An options appraisal is being undertaken to evaluate all potential options for the long term future of the Peebles High School site. It's estimated to be complete by Easter 2020.
Two boys have been arrested and charged in connection with the fire.