The leaking roof at Parliament Buildings in Belfast is to be replaced, it has been announced.
At least £4.5 million will be spent on the work, which is due to begin later this year or early next.
The problem has become so bad that buckets are used on the 4th floor to catch dripping water during heavy rain.
A spokesman confirmed: "The building will be permanently damaged if we don't fix it. The fabric of the building must be protected."
A design team has already carried out preliminary work to draw up a technical solution and a contractor is expected to be appointed sometime in the autumn.
The listed building where the Northern Ireland Assembly meets will remain open throughout the work, but MLAs and staff have been warned to expect some disruption.
Some staff will be temporarily relocated, but at this stage it is not known how long the work will last.