Crosshouse Primary School will not reopen to pupils at the start of the school term.
The village primary school is currently undergoing a £6.8 million refurbishment and extension but delays have scuppered plans to reopen at the start of the new term in a few weeks.
East Ayrshire Council bosses wrote to parents recently to let them know that the school would not reopen on August 18, conceding that the situation was "not ideal" and will cause further "uncertainty and disruption".
The local authority's head of facilities and property management Andrew Kerr blamed "significant supply difficulties" and said that the contractor is still experiencing delays to key materials.
Council chiefs are hoping a two-week delay will enable the school to fully reopen on Wednesday, September 7.
In the meantime, students will continue to use the former Kirkstyle Primary School building.
But pupils face being off for four days to allow staff to pack up Kirkstyle and set-up new classrooms at Crosshouse.
The letter to parents reads: "As mentioned in my previous letter, the construction industry is continuing to face significant supply difficulties and the contractor is still experiencing delays to key materials required for the full completion and certification from building control.
"Whilst there is still a very slim chance that the outstanding items may arrive in the next week, and to ensure we can provide a greater degree of certainty we believe that the best course of action is to delay the move for 2 weeks and progress with Plan B as previously indicated."
The two-storey extension at the school will house a new integrated dining and PE block, five additional teaching spaces for both primary school and communication centre use and eight communication centre classrooms that will each have dedicated quiet rooms.
The letter concludes: "I appreciate this is not an ideal situation and will cause further uncertainty and disruption, which I can only apologise for.
"As pupils will be continuing with the decant to Kirkstyle further operational details and specific transport information for new P1 pupils will be issued in a separate communication from the head teacher."
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