The Town Hall was closed in 2013 to undergo major earthquake strengthening and refurbishment.
At that time the budget for the work was 43-million dollars, then it went up to 60-million, 90-million, and most recently in 2019 it reached 112-million dollars.
Now, documents for a council meeting next week, show it could come in another nine percent over budget, which is around 10-million dollars.
Covid-19 supply chain issues are largely to blame.
The documents say the Wellington construction market is extremely stretched and this is feeding through into escalation of material and labour costs.