Has your building received a concerning New Building Standard (NBS) earthquake rating? Or has a Detailed Seismic Assessment (DSA) highlighted structural weaknesses?
Instead of being alarmed, understanding Earthquake Prone Building (EPB) assessments can be the first step toward compliance and genuine property improvement. Whether you’re a commercial landlord, property investor, or business owner, we’ll interpret your DSA and show you practical steps to address your building’s seismic concerns.
The DSA assessment is the most thorough evaluation of your building’s seismic performance. It goes beyond basic assessments to examine your building’s structural integrity and potential vulnerabilities in detail.
This comprehensive health check for your property involves advanced engineering analysis through sophisticated computer modelling to simulate earthquake responses and provides detailed calculations of seismic capacity.
When your DSA results indicate problems, the report will highlight several critical structural weaknesses that need immediate attention. It will also detail how your building might behave during an earthquake, including likely damage patterns, potential failure modes, and risks to occupants and neighbouring properties.
As one of the key outcomes of the DSA assessment, your NBS percentage shows how well your building would perform in an earthquake compared to a new building constructed to today’s standards. Under the Building (Earthquake-prone Buildings) Amendment Act 2016, buildings below 34% NBS are legally considered earthquake-prone, requiring action to either strengthen the building to meet the necessary seismic standards or demolish it within specified timeframes.
Common issues that can contribute to a low NBS earthquake rating include:
An EPB assessment is a formal evaluation required by the Building Act 2004 for buildings that might be earthquake-prone, considering factors like your building’s structural capacity, importance level, and seismic risk. It also draws on information from your DSA and NBS rating to determine whether your building meets the legal definition of earthquake-prone—whether it is likely to collapse in a moderate earthquake, potentially causing injury, death, or damage to other properties.
With your Earthquake Prone Building assessment, you can develop a comprehensive action plan and address immediate safety concerns. From there, you can work with structural engineers like Gridline to develop a strategy for seismic strengthening of existing buildings, ensuring that it meets legal requirements and aligns with your budget and business objectives.
Understanding your EPB seismic assessment helps you make informed decisions about your property's future by identifying which structural weaknesses pose the most significant risks. This allows you to develop a staged approach to strengthening work if needed, spreading costs over time while addressing the most critical issues first.
Beyond meeting legal requirements, the assessment can guide improvements that enhance your building's value and marketability. It can also help you identify opportunities to combine seismic strengthening with other renovations or upgrades, potentially reducing overall costs and minimising disruption to tenants.
Receiving a low NBS rating or concerning DSA results might feel overwhelming, but it’s important to remember that understanding your building’s seismic status is the first step towards improvement. Through comprehensive EPB assessments, proper planning, and expert guidance, you can transform your earthquake-prone building into a resilient, valuable asset that meets modern safety standards.
Work with Gridline NZ's team of experienced structural engineers who specialise in helping property owners navigate the complexities of seismic assessments and strengthening. When you work with our team, we will guide you through the assessment process, helping you transform your low-NBS properties into compliant and safe investments.
Contact us for a consultation about your building’s seismic status and secure your building’s future!