Earthquake-Prone
Buildings
Our engineering assessments can confirm if buildings are earthquake-prone.
Owning an earthquake-prone building in New Zealand affects insurance cover and financing and provides a heightened safety risk for occupants and surrounding property.
To confirm if your building is potentially earthquake-prone (or not) an engineering assessment is required.
The Structural engineers at BTW Company are suitably qualified to evaluate a buildings’ earthquake structural performance, establishing the degree of risk and the possible need for remedial work to meet building code – including design works if required.
How does the earthquake-prone building process work?
Initial Seismic Assessment
Our earthquake-prone building service can begin with a cost effective Initial Seismic Assessment (ISA) following the Initial Evaluation Procedure (IEP). This sees our structural engineers determine the building’s level of performance in relation to current earthquake code.
We’ll compare the seismic performance score against the grading system to find the building’s seismic grade (A+, B, C, D or E) and the related description; ‘earthquake-risk’ or ‘earthquake-prone’.
This is, essentially, a screening tool to see if there are attributes that will make the building a risk (or not). If your building is very old and made from unreinforced masonry, it is likely best to move straight to a more detailed assessment, strengthening or both.
Detailed Seismic Assessment
If required, we can complete a Detailed Seismic Assessment (DSA) which is a more intensive evaluation that identifies the likely performance of the building in an earthquake, including identifying any critical structural areas that may need addressing.
For buildings that are deficient, this assessment provides an idea of the structural upgrades that may be necessary to meet the preferred level of service when compared to the New Building Standard (%NBS) — often 34%NBS or 67%NBS, depending on the building and its use.
Structural Strengthening — Design and Documentation
If the evaluations find remedial strengthening works are necessary, we can provide a structural design and documentation service to upgrade the building to the desired level of performance. This includes structural calculations, drawings, specifications and contract supervision to enable our client to get building consent for any required remedial work.