Chances are, if you are involved in the design, construction or fit-out of interior commercial spaces, you will have been required to provide a PS1 or estimate the cost of materials for a seismically compliant design. Even if you’ve been in the industry for years and it’s never been your problem, you may now notice it’s a question that’s being asked of you.


Supply Chain Pressure

There are several reasons behind this change. The need is driven by an increasing council requirement for consent at an early stage, and also by the challenges of supply chains, and a need to order materials early. Designs need to be signed off and materials need to be ordered earlier than ever. Pressure on the supply chain means a Just In Time strategy is now too risky so designs need to be locked in early. No one wants a last minute design change because the seismic engineering requires it. 


Tender Requirement

Equally, leaving the cost of interior seismic engineering as an unspecified amount on tenders is becoming less acceptable. Those tendering for work need to be able to show their planned design and cost will stand once the project is underway. However, as a contractor, it’s a significant cost to include a PS1 for a tender you may not win.


The range of construction professionals needing to secure a PS1 or provide an accurate estimate of costs is increasing by the day! Asset owners, head contractors, designers, architects, project managers, quantity surveyors, fit out suppliers and fit out contractors are all needing to dive into the world of seismic calculations.


Seismic Calculators and Wizards

The use of seismic calculators have been increasing in response to these changes. The ability to input the variables of the build into a wizard, and check that the outcome will be seismically compliant, gives confidence and accuracy to a quote or tender application. The costs around seismic design have often been referred to as a dark art, with non-engineers left uncertain of their design prior to a PS1 completed by a seismic expert. However, the seismic calculators are able to provide a pathway to achieving compliance, and provide more certainty for users.


It sounds like a fairy tale ending to a tricky story – as technology saves the day. Unfortunately there are some limitations which make the solution less than perfect. 


  • The majority of seismic calculators apply only to designs for buildings of Importance Level 1-3. This excludes buildings that need to continue functioning after an earthquake, such as a hospital or some police stations.
  • Many calculators limit their use to buildings under a certain size, or ceilings under a certain weight
  • Most calculators are specific to the company that creates them, limiting the choice of product to their range. This is not always ideal when contracts haven’t yet been given, or when more flexibility is needed given supply chain challenges.
  • Calculators can quickly become out-of-date. The building code is updated every six months. This means that the calculators must also be continually updated to stay inline with the latest code. 


Calculators are a great guide, but do not give you 100% certainty. That only comes with a signed-off PS1 reviewed by an engineer with interior seismic expertise.


However, in many cases, an engineer sign off may not be needed just yet.  This is when something more than a calculator is required; a wizard with more flexibility than a simple step by step approach. 


More than a Wizard

Choosing a web app such as Prenguin that provides the functionality of a wizard but with greater depth of engineering capability may help get around the issues discussed above. Built as intelligent software, Prenguin is constantly updated to reflect the latest changes in the building code, and the resulting designs have 100% certainty of being seismically compliant. This is because the software is designed by seismic engineers specialising in the field of interior engineering. The complexity that sits behind the calculations ensures the app can be used for buildings at an IL4 level, and can handle calculations for ceiling weights and heights.


Prenguin designs for standard ceiling and partitions are detailed and accurate enough to submit to an engineer for a PS1. With the confidence that comes with a Prenguin calculation, a PS1 can be signed off within hours.


If you’d like to give Prenguin a try, you can register directly from the website (top right corner of the page) or contact BVT for some help to get started.