An Initial Seismic Assessment (ISA) serves as an initial evaluation of a building's likely seismic performance. It offers a broad indication of a building's structural earthquake strength in relation to the New Building Standard. It's important to note that ISA is primarily based on engineering judgment and lacks a rigorous scientific foundation, relying on visual inspections or drawing reviews.

For the utmost quality and credibility, it is imperative that an ISA is conducted or overseen by NZ Chartered Professional Engineers (CPEng) or their equivalents. These professionals should possess relevant experience in building design and earthquake evaluation, as well as specific training in the Initial Evaluation Procedure, as emphasized in the 'Guidance for Territorial Authorities and Property Owners on Initial Seismic Assessments' by MBIE.