When IS 465:2026 was introduced, I welcomed the intent behind it but had reservations about how it might be interpreted by engineers. Reading several reports tells me I was correct. I reference one report where a house was given a group 4 classification, indicating the worst possible level of structural damage, with widespread deterioration and a clear finding of evidence of chemical damage. There is evidence of sulphate attack gypsum replacing binder secondary eclogite formation, mobile sulphates within the concrete system and full carbonisation of the concrete metrics. This describes concrete systems that undergo significant internal change and ongoing failure. Yet, despite this, the home in question is excluded from remediation. The conclusion drawn was that the sulphates are likely externally sourced and not linked to defective blocks.

This is where the core issue is now arising, with decisions driven by a heavily focused but narrowly presented one-day snapshot of sulphate content. The most recent research, by Leemann, Münch and Dunlop in 2026, demonstrates that internal sulphate attack, ISA, can occur even where sulphate content is low because the sulphates have consumed, transformed, distributed and leached over time. The damaging chemistry does not remain static. It evolves, which means a low sulphate reading today does not mean sulphate-driven damage was never present. It may simply mean the reaction has already run its course and the sulphates have been used up. It is like arriving at a house that has been burnt out. Flames may no longer be seen and there may be little smoke remaining but the damage to the structure is still there. It cannot be concluded that there was no fire simply because the active stage has passed. There was a fire once upon time.

This raises deeper concerns. Should decisions under IS 465 rest mainly with engineering interpretations and threshold readings or should they be grounded in a full materials science analysis of how these chemical systems evolve? There is a risk that homes are being judged on what chemical traces remain rather than the scientific reality of how the damage actually developed. Will the Taoiseach ensure that interpretation of sulphate-related damage under IS 465 is led by independent materials science expertise in order that evolved internal chemical deterioration is properly recognised, rather than leaving decisions to be based primarily on scheme engineers' assessments of present-day sulphate readings?

I thank the Deputy for raising this issue. Clearly, the defective concrete blocks issue has evolved. It is a very complex issue, which the Government is addressing in the first instance by agreeing and allocating very significant amounts of funds to the affected homeowners to enable families to rebuild their homes and get on with their lives. I believe in a multidisciplinary approach to issues. The Deputy's basic query is whether IS 465 should be led by independent materials science expertise or by engineering. I think perhaps it should be both. There always have to be inputs.

The grant scheme is underpinned by the national testing standard. We have agencies, including the National Standards Authority of Ireland, NSAI, and so on to determine the standards. IS 465 was revised on 2 June and that revision now needs to be examined in more detail. The Government remains committed to following the science when it comes to homes affected by defective concrete blocks, as per the provisions of the Remediation of Dwellings Damaged by the Use of Defective Concrete Blocks Act 2022. The Minister for housing intends to carry out a review of the operation of the Act as quickly as possible. That is provided for under the legislation. The issue of how damage interpretation is dealt with under the revised national standard will be addressed as part of that review.

In the meantime, the scheme can continue to operate to fix homes for the many homeowners who have already received a determination and a grant amount under the former standard. Since the Government commitment of 2020, more than 3,500 homeowners have been progressing through the defective concrete blocks grant scheme, with grants covering 100% of eligible costs up to €462,000 per household. That is a 10% increase since 2023. Over €336 million has been spent to date, which shows the scheme is really ramping up, with a record €175 million allocated this year. More than 500 homes have been completed, with 750 currently undergoing remediation. Approximately 80% of the affected homes are in Donegal. This is a significant scheme by any yardstick. I do not think it has any precedent in terms of its scale.

The issue the Deputy raised is a technical issue, albeit a significant one, arising from recent changes to the national standard governing the scheme. The changes have to be assessed and a review process is required under the legislation. IS 465 is the national standard currently used to assess damage caused by mica or pyrite in affected homes.

The reason I raised this issue is that right now, as we speak, there will be people going in with foundations with levels of ISA in them. They will potentially be building on top of a foundation that may fail in the future. I am talking about being fiscally responsible. As the revised IS 465 has been published, there is now a trigger. Can the Taoiseach give me dates for this? I do not want people to be building on top of foundations that contain an ISA and then, in a year or two years' time, the foundations on which their brand-new home is built are tested and shown to be damaged. It is about fiscal responsibility and doing things right. Is it possible to get some kind of timeframe for when this will happen? As the Taoiseach said, there are homeowners progressing through the scheme.

For what is the Deputy seeking a timeframe?

I am asking for a timeframe for when this decision will be implemented. The trigger is off now with the revision of IS 465. When will the Minister for housing review and adapt to these changes?

The revision to IS 465 was made on 2 June. Under section 51 of the Act, the Minister must review the scheme following that revision. The review will examine several aspects of the scheme, including treatment of foundations. Findings must be reported to the Oireachtas within three months of completion. That is the timeline.