The Department of Education says the ground floors in two schools closed over structural concerns will be reopened after the mid-term break.
It also says prefabs will only be used as a 'last resort' if schools are forced to close due to the time required for installation - unless prefabs are already on site.
Three schools were closed this week after concerns were raised over structural issues.
Engineers have been tasked with completing safety examinations of all 42 schools built by the company Western Building Systems by the end of the mid-term break.
Today, officials said a number of 'structural engineering solutions' will be put in place next week for the two closed schools in Tyrrelstown in Dublin - meaning parts of the schools (Tyrrelstown Educate Together National School and St Luke’s National School) will be able to reopen on Monday November 5th.
The Department said in a statement: "This will facilitate about half the classrooms in each school and special needs children will be prioritised.
"It is envisaged that preparatory work on these solutions will commence on Monday, 29 October, with a contractor to commence on site on Tuesday, 30 October."
Work is ongoing to find interim accommodation for other classes impacted.
Meanwhile, Ardgillan Community College - the first school to close over structural issues - will be able to accommodate all students after the mid-term break, by utilising an adjacent community hall and a neighbouring school.
The Department says it will prioritise opening ground floors - and that prefabs will only be considered as a 'last resort'.
They also say that correspondence has been received from Western Building Systems, and has now been passed on to the Chief State’s Solicitor’s Office.
Earlier today, Western Building Systems called on the Government to explain how three schools it “previously deemed compliant” have now been fully or partially closed for safety reasons.
In their statement this evening, the Department of Education said 'Certificates of Substantial Completion' are not proof of compliance with building regulations and "should not be confused with such".
