What Is the FEMA P-58 Seismic Methodology?

What Is the FEMA P-58 Seismic Methodology?

The FEMA P-58 Seismic Methodology is a performance-based approach for evaluating how buildings will fare during earthquakes.

It was developed by the Applied Technology Council (ATC) as part of the ATC-58 project series for the Federal Emergency Management Agency (FEMA).

Unlike traditional code, which has a strong focus on minimum life-safety, the FEMA P-58 provides a complete risk assessment of a building’s likely earthquake damage and its consequences. 

For example, instead of “ensuring the building won’t collapse”, it outlines estimates of how much damage could occur, how long repairs might take, what it might cost, and how much downtime would be needed, etc.

How Performance-based Seismic Design Works

Performance-based seismic design (PBSD) shifts the focus from meeting minimum building code safety standards to meeting owner-defined seismic goals.

Simply, building codes aim to prevent building collapse in a “design level” earthquake. However, they don’t guarantee that the building will be usable or economical to repair afterwards. PBSD, though, does.

At the beginning of a PBSD, the owners and stakeholders set clear performance targets. This could include maximum allowable downtime, repair costs, etc. For example, a hospital may require full functionality instantly after a moderate quake.

By using tools like the FEMA P-58, professionals can model and compare design options early in the process. This then allows them to develop a seismic design plan that meets the goals of the owners or stakeholders to meet their post-seismic goals.

When to Use FEMA P-58

Not every project requires a full FEMA P-58 analysis. After all, it requires additional effort and design. However, it is always recommended, and even insights from such methodology are valuable.

High-Value or Critical Facilities

This could include anything such as residential homes, hospitals, emergency operation centers, data centers, telecommunication hubs, major manufacturing plants, or power utilities. Pretty much, any building that must function or be inhabited after an earthquake.

These facilities, if they encounter downtime, could be life-threatening. That’s why such facilities should have a FEMA P-58 seismic plan instead of an “ordinary” code-compliant seismic design plan.

Protecting What is Inside the Building

Some projects are less about protecting the building itself and more about what is inside.

If you and your family sleep at home at least 8 hours every night, then there is at least a 33% chance you and/ or your family will be home during the next major seismic event. Your family and loved ones deserve the very best when it comes to seismic protection, and the minimum required work is not designed to protect your home or family from extensive damage.

For general buildings besides your home, these could be anything from museums to archives, high-tech laboratories, art galleries, data storage centers, and so forth.

In these cases, whether the building survives or not isn’t the key issue. The goal is to protect the goods inside. Therefore, a FEMA P-58 plan will look into the probability of things like sprinkler leaks, ceiling collapse, etc., to protect them.

Projects in High Seismic Risk Zones

If a structure is located in an area with a high likelihood of seismic activity, like California’s San Andreas and Hayward fault regions, the Pacific Northwest, etc., a PBSD could help reduce the deadliness of the “big one”.

For example, the “big one” in the San Francisco Bay Area could be a magnitude of 7.5. However, codes only ensure that most properties, such as residential, can handle minor quakes. Therefore, major earthquakes still pose a serious threat with standard seismic codes.

Real Estate Transactions & Investments

FEMA P-58 isn’t just for design. It can also be used as a powerful due diligence and risk assessment tool when buying, leasing, or financing a building.

By getting a professional to review the current real estate plans, you’ll be able to determine how earthquake-ready the property is. This can then sway your decision on whether or not to make the purchase.

Construction Retrofits

When retrofitting existing buildings that are known to be vulnerable, a FEMA P-58 can guide a targeted retrofit strategy to achieve certain performance metrics. This ensures that your retrofit upgrades protect your property in a way suited to your goals.

The Process of FEMA P-58

If you decide to use FEMA P-58 on a project, the process looks a little like the following:

1. Define Performance Goals: Establish clear, quantitative resilience objectives early in the project. Identify acceptable limits for downtime, repair costs, and safety risks.
2. Assemble a Qualified Design Team: Engage experienced professionals who are familiar with FEMA P-58/PBSD. This may include architects, MEP engineers, seismic risk consultants, contractors, and cost estimators.
3. Conduct Preliminary Performance Assessment: Use the conceptual design phase to run early FEMA P-58 analyses. Test multiple structural systems and identify risky elements or design.
4. Refine Design and Align with Goals: Move into a detailed design with more precise FEMA P-58 assessments. Use an iterative analysis-feedback-design cycle until all the performance indicators meet targets.
5. Final Verification and Implementation: Perform final FEMA P-58 analysis to prove design meets performance goals. Document all expected losses, downtime, and causality risk for personal or stakeholder review.

Benefits of FEMA P-58

Using the FEMA P-58 methodology (and PBSD in general) can provide multiple benefits for building owners, occupants, and even the broader community.

Here are some major advantages:

Saving Lives, Reduced Downtime, and Business Disruption

The biggest benefit of getting a FEMA P-58 seismic design is to save lives. When retrofitting your home, the goal is to protect everyone inside and prevent as much damage as possible.

For a non-residential structure, it is about protecting the staff and clients inside, plus the ability to remain functional or recover quicker.

Traditional code-designed buildings, in some circumstances, can be closed or non-inhabitable for months (maybe even years) for repair after a big quake.

With a P-58-optimized building, however, you can specially develop a building design where the building doesn’t need repairing after a certain magnitude of quake.

This is vital for not only your home, but also for community buildings, like hospitals and grocery stores. If such buildings need extensive repairs after a large quake, it could be life-threatening to many in the area.

Not only this, but it could be financially threatening if your home becomes inhabitable or your business need to close down due to repairs for a while. This may even put you into bankruptcy.

Financial Risk Control

Using a FEMA P-58 also means fewer financial surprises when we experience an earthquake. The reason for this is that you likely know the outcome (in regards to dollars) based on the analysis provided.

For example, with a standard seismic-code property, you won’t know how much damage you might encounter. With a FEMA P-58 design, though, you’ll have realistic values on how much it may cost you if your building needed to be repaired due to a quake.

From a risk management perspective, the P-58 enables what people like to call a risk-based design. While developing the design, you set an acceptable risk (in terms of dollars) and create it in such a way.

Let’s say you don’t want the repairs of your building to exceed 10% of its value after a magnitude of 5 or more. In that case, in the previous design and development steps, the building would have been designed to meet these goals.

Enhanced Property Value and Marketability

Alongside the above, buildings designed for high seismic performance can demand a high market price (especially in high seismic zones).

For instance, in regions like California, some buyers and tenants are looking for buildings with higher seismic ratings. This is because some regions in California have high seismic risk.

If you can show that your building has, for instance, a USRC Platinum rating or has been performance-designed to minimal damage, it’s a strong selling point.

In fact, FEMA has even mentioned that better building earthquake resilience does increase the value of the property.

Community and Environmental Resilience

Beyond the individual building and owner, there are broader societal benefits to designing with FEMA P-58.

Simply, a community with more earthquake-resilient buildings will recover faster after a disaster. They can support the entire community.

A FEMA P-58 designed building will likely need less extensive repairs, demolition, etc. Therefore, services can be spread elsewhere and to those who are more in need.

Conclusion

Overall, FEMA P-58 enables homeowners, building owners, designers, and investors to move beyond the one-size-fits-all seismic design approach.

By quantifying earthquake risks in terms of dollars, downtime, and casualties it brings clarity to the seismic performance of your property.

If you’d like a FEMA P-58 seismic design today, contact our professionals at Avant Garde.

We’ll be more than happy to listen to your seismic goals, develop a plan, and, most importantly, execute on it.