LPT operates on a self-assessment basis and it is a matter for the property owner in the first instance to calculate the tax due based on his or her assessment of the market value of the property. When making an assessment, issues such as defective construction would be one of the factors that a property owner should take into account in valuing their property.
The LPT legislation provides for an exemption from LPT for properties with 'significant pyritic damage'. The qualifying criteria in respect of this exemption were modified by the Finance (Local Property Tax) (Amendment) Act 2015. Details of the qualifying criteria are available on the Revenue website at https://www.revenue.ie/en/property/local-property-tax/exemptions/properties-certified-as-having-pyritic-damage.aspx
I have no plans for further reliefs and exemptions from LPT.