Seismic Assessments

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Seismic Assessments

The Engineering Assessment Guidelines - Nov. 2018 version 1 provide a technical basis for seismic assessment of existing buildings in New Zealand. They provide methods for two levels of assessment. Initial Seismic Assessment (ISA) provides a broad indication of the likely level of seismic performance of a building. In some cases, an ISA will be followed by a more comprehensive Detailed Seismic Assessment (DSA).

The scope of an Initial Seismic Assessment (ISA) typically includes the following:

  • Request and review the property files. The focus of the review is on the available drawings and
    design information for the subject building.
  • If site specific soil data is unavailable, GNS geotechnical maps will be used to identify the likely site soil class type.
  • Visual inspection of the accessible parts of the building. The purpose of the inspection is to verify that the plans within the property files are representative of the building, and document
    any visible structural features which may affect the earthquake performance of the building.
  • Assessment of the earthquake rating of the building in terms of percentage of the New Building
    Standard (%NBS) using the Initial Evaluation Procedure (IEP) (Section B3.2 in accordance with Part A and
    Part B of seismic assessment guidelines.
  • The assessment will be accompanied by a report in accordance with the requirements of seismic assessment guidelines for ISAs (Section B1.1)
  • The report will be approved by a Chartered Structural Engineer experienced in seismic assessments.

The scope of a Detailed Seismic Assessment (DSA) varies for each building and an overview is available in the seismic assessment guidelines Part C1.1.1


Here are some examples of seismic engineering projects we’ve completed: