METHODOLOGY
How Resilience Explorer® | Property calculates natural hazard risk.
This page sets out the risk-classification framework Resilience Explorer® | Property applies, the consequence modelling behind every property-level rating, and the scope and limitations of every report. It is intended for GIS managers, natural hazards advisors, and senior consents planners.
Understanding NPS-NH risk classifications
The National Policy Statement for Natural Hazards 2025 (NPS-NH) is national direction issued under the Resource Management Act 1991. It requires councils to assess natural hazard risk using a standardised framework when considering subdivision, use, and development.
Under the NPS-NH, risk is determined by combining likelihood (how often a hazard event may occur) and consequence (potential impacts on property and life safety). These are combined using the risk matrix in Appendix 1 of the NPS-NH to classify risk as Low, Medium, High, or Very High. Where property and life-safety consequences differ, Resilience Explorer® | Property adopts the higher consequence level in determining overall risk.
Risk categories
Timeframe
The NPS-NH requires consideration of climate change impacts for at least 100 years (Policy 6). Where risk increases over time, this may influence consent decisions, particularly for long-lived assets. Resilience Explorer® | Property runs both a present-day and a long-term (100-year) assessment for every property, using the climate scenarios agreed with your council.
Consequence modelling
Property damage and life-safety consequences are derived using hazard-specific consequence models embedded within Resilience Explorer®. For property damage, vulnerability (damage ratio) functions are used to estimate the expected level of building damage based on hazard intensity (for example, flood depth or liquefaction category). These functions represent typical damage responses and do not account for site-specific building design, floor levels, or construction details.
For life safety, hazard-specific thresholds are applied to classify potential life-safety consequences based on hazard intensity. These classifications indicate the level of potential harm under the modelled conditions and do not represent predicted fatality counts.
Consequence functions and their basis
Resilience Explorer® | Property's consequence calculations use vulnerability (damage ratio) functions derived from a combination of published academic literature, post-event damage studies from New Zealand events including the Canterbury earthquake sequence and the 2023 North Island weather events, and Urban Intelligence's own peer-reviewed research. The functions are calibrated for New Zealand building stock and construction typologies. They are reviewed annually and updated when new evidence becomes available.
Scope and limitations
Resilience Explorer® | Property assessments provide a screening-level classification of natural hazard risk at the subject site, based on regional hazard datasets and modelling available at the time of report generation. Results may not reflect site-specific ground conditions, building design, floor levels, or proposed mitigation measures.
Resilience Explorer® | Property does not evaluate:
The effects of any specific subdivision, use, or development proposal
The effectiveness or cost-effectiveness of mitigation measures
Residual risk following mitigation
Whether development may create or increase natural hazard risk on other sites
These matters must be considered separately as part of a proposal-specific consent assessment. Properties classified as Medium, High, or Very High risk may require detailed specialist investigation to support consent applications. Risk classifications follow the NPS-NH Appendix 1 risk matrix as prescribed.
Reports generated by Resilience Explorer® | Property provide a screening-level assessment of natural hazard risk based on regional hazard datasets available at the time of generation. They support preliminary assessment and do not replace site-specific investigations, detailed engineering analysis, or professional advice tailored to a specific development proposal.
Property is a module of Resilience Explorer®, built by Urban Intelligence Ltd, Ōtautahi Christchurch.
