Why Building Importance Level Matters More Than You Think
BackWhen it comes to seismic compliance in Australia, understanding your building’s Importance Level (IL) is more than a box-ticking exercise—it directly impacts the performance, safety, and cost-efficiency of your project.
Under AS1170.4, different structures are assigned an Importance Level from IL1 to IL4. The higher the level, the more stringent the seismic requirements. For example, hospitals, emergency facilities, and critical infrastructure typically fall under IL4, meaning their essential systems must remain operational following a seismic event.
So what does that mean for builders, architects, and project managers? It means early coordination with the right engineering team can make all the difference.
Engineering for Performance, Not Just Compliance
At KUSCH, we specialise in seismic design for non-structural services—pipework, cable trays, ceiling supports, and mechanical services. We don’t just help you tick the compliance box—we work with your team to find efficient, buildable solutions that perform under pressure.
Take the Lyell McEwin Hospital Expansion as an example. We’re proud to be partnering with Watson Fitzgerald and Built. on this essential healthcare upgrade. Our scope includes:
Seismic design of mechanical services to meet IL4 requirements under AS1170.4
Designing low-profile skid frames for stair pressurisation fans, enabling off-site assembly and maintaining strict roof height limits
Delivering solutions that keep safety, constructability, and architectural constraints in balance
With seismic compliance, it’s easy to get lost in the detail or overengineer a solution that drives up cost. Our approach is different—we focus on what’s fit for purpose, always asking: How can we achieve performance, without unnecessary complexity?
Why It Matters to You
Whether you’re planning a hospital, school, or community centre, getting the Importance Level right from the start affects everything from anchor selection to the extent of seismic bracing required. Missteps in this area often lead to cost blowouts, redesigns, or worse—non-compliance.
With KUSCH, you’ll always know what’s required, what’s not, and how to meet the brief in the smartest, most efficient way possible.
Need help navigating IL4 or seismic certification for your next project? Get in touch—we’re here to help.
