That requirement is explicit in procurement documents published last week for the project, estimated to be worth £1.1million.
The council intends awarding the contract in September with shortlisted firms invited to submit formal tenders by the end of July.
The facility, on a site next to Earlston Primary and due to be operational next year, will replace the dispersed provision for youngsters on the autism spectrum which is currently delivered at Wilton in Hawick, St Ronan’s in Innerleithen and at Howdenburn Schoolhouse in Jedburgh.
It currently costs the council around £150,000 per pupil per year to have Borders children with complex needs educated outwith the region.
“If pupils who might otherwise be placed outside the authority to meet their educational needs choose to stay in the new facility, then significant savings will accrue,” stated a recent report to councillors.
“The Earlston site provides close links with learning communities and other educational opportunities, is in close proximity to primary and secondary [Earlston High] mainstream provision and provides life-skills opportunities within the town centre.
“It also provides improved accessibility within the Borders, reducing travelling times for vulnerable children and maximising the use of expertise within SBC and NHS Borders.
“The centre will provide full and part-time school places, assessments, training and outreach.”
Councillors have already given planning consent for the design which will be of traditional masonry and rendered walls with a large feature rooflight and aluminium doors and windows. The contract includes the provision of a hard and soft landscaped garden.