Seismic Assessment of Buildings - Initial Evaluation Procedure (IEP) and Detailed Seismic Assessments

A typical industry standard requirement is that a building must reach a minimum of 33% NBS to not be considered “potentially earthquake prone”. The term “earthquake prone” implies a high level of building damage is expected as a result of a “design” earthquake and this obviously impacts on both the building and the occupants of the building. In many instances, if the building is assessed to be above this 33% NBS threshold then many Councils will not demand any building upgrade.

However if the building achieves a rating between 34% and 67% of NBS it is listed as “potentially an earthquake risk”. The term “earthquake risk” implies high (at the lower levels of %NBS achieved) to minor (at the higher levels of %NBS achieved) building damage in a “design” earthquake.

Following the recent tragic events in Canterbury some councils, banks and insurance providers are requiring older buildings to achieve higher levels of %NBS, typically above 67%NBS to reduce the risk to occupants and the building. If a building does not meet the required %NBS required by an interested party then strengthening the structural components of the building is one option that can be investigated. Markplan’s extensive engineering experience can help our clients to assess the range of options available and the first step is usually to carry out a Detailed Seismic Assessment, also following the NZSEE guidelines. We note that it is not a pre-requisite for an IEP to be carried out if a Detailed Seismic Assessment of the building is planned. The detailed assessment reviews the structure in significantly more detail than an IEP in order to provide a means for more accurate assessment of the building’s performance in an earthquake.

Markplan has noticed some interesting developments in recent times in regards to IEP assessments such as • Insurance Providers: older buildings (without assessments or strengthening works) are requiring higher insurance premiums to cover the increased risk. Building owners need to consult their insurance providers to determine what %NBS is acceptable to them to allow reductions in their premiums. • Property Values: many Valuers are factoring in IEP results when valuing a property. A low %NBS may lower the value of a property to offset the expected future costs of strengthening work required. Owners should equally expect older upgraded buildings of higher %NBS to have more favourable valuations. • Banks and lending institutions: it is starting to become a requirement of some banks and lending institutions to show that an IEP assessment has been completed for a building as part of their lending criteria. Buildings of lower %NBS may attract higher finance costs or be more difficult to finance. • Leasing: some tenants may choose to only lease buildings which have been designed to modern codes or have been upgraded with strengthening works to an acceptable level relative to %NBS. There is a definite shift in awareness and understanding of these issues and if Markplan is able to assist you in any way please contact us sooner rather than later. A small investment in engineering time and expertise now may save you significant insurance or financing costs in the years ahead.

A typical industry standard requirement is that a building must reach a minimum of 33% NBS to not be considered “potentially earthquake prone”. The term “earthquake prone” implies a high level of building damage is expected as a result of a “design” earthquake and this obviously impacts on both the building and the occupants of the building. In many instances, if the building is assessed to be above this 33% NBS threshold then many Councils will not demand any building upgrade.

However if the building achieves a rating between 34% and 67% of NBS it is listed as “potentially an earthquake risk”. The term “earthquake risk” implies high (at the lower levels of %NBS achieved) to minor (at the higher levels of %NBS achieved) building damage in a “design” earthquake.

Following the recent tragic events in Canterbury some councils, banks and insurance providers are requiring older buildings to achieve higher levels of %NBS, typically above 67%NBS to reduce the risk to occupants and the building. If a building does not meet the required %NBS required by an interested party then strengthening the structural components of the building is one option that can be investigated. Markplan’s extensive engineering experience can help our clients to assess the range of options available and the first step is usually to carry out a Detailed Seismic Assessment, also following the NZSEE guidelines. We note that it is not a pre-requisite for an IEP to be carried out if a Detailed Seismic Assessment of the building is planned. The detailed assessment reviews the structure in significantly more detail than an IEP in order to provide a means for more accurate assessment of the building’s performance in an earthquake.

Markplan has noticed some interesting developments in recent times in regards to IEP assessments such as • Insurance Providers: older buildings (without assessments or strengthening works) are requiring higher insurance premiums to cover the increased risk. Building owners need to consult their insurance providers to determine what %NBS is acceptable to them to allow reductions in their premiums. • Property Values: many Valuers are factoring in IEP results when valuing a property. A low %NBS may lower the value of a property to offset the expected future costs of strengthening work required. Owners should equally expect older upgraded buildings of higher %NBS to have more favourable valuations. • Banks and lending institutions: it is starting to become a requirement of some banks and lending institutions to show that an IEP assessment has been completed for a building as part of their lending criteria. Buildings of lower %NBS may attract higher finance costs or be more difficult to finance. • Leasing: some tenants may choose to only lease buildings which have been designed to modern codes or have been upgraded with strengthening works to an acceptable level relative to %NBS. There is a definite shift in awareness and understanding of these issues and if Markplan is able to assist you in any way please contact us sooner rather than later. A small investment in engineering time and expertise now may save you significant insurance or financing costs in the years ahead.