Performance-Based Design & Prescriptive Methods: It’s Time to Work Hand in Hand

Feb 26, 2018 | FSE, News

We asked Michael Strömgren a few questions about performance-based design, prescriptive methods, and the link between the two.

What does “performance-based fire protection” mean?

It’s about integrating tailored-made fire safety for the design situation, taking into account the fire risks relevant to that specific building or to other objects in the built environment. In performance-based fire protection, the designer has to assess the potential fire scenarios for a situation and design the fire safety based on the identified risks.

Why is there a need to integrate the prescriptive approach?

I think it’s because the prescriptive approach has been around for a long time and, in some areas, it may be hard to define the exact performance levels. The prescriptive codes have a long history and, while they have their limitations, they also have advantages, such as being more straightforward to apply.

Do you think that buildings built using a performance-based approach will be as safe as buildings built using the prescriptive approach?

I believe that performance-based design has more potential than prescriptive design, but of course both methods have pitfalls.

Performance-based design is quicker to adapt to new emerging trends and risks, such as new fire loads and new occupant scenarios, and it addresses each specific risk. However, we need to make sure that all stakeholders are on board. For example, we don’t want performance-based design to reduce by too much the flexibility of use of a building.

Prescriptive regulations also have limitations. They may add unnecessary fire safety measures, may not address certain risks, and may fall behind when the fire environment changes.

How do you think the regulatory regime in different European countries will evolve?

There will be an increased interest in looking at the regulatory system as a whole: the role of authorities; how the regulation relates to industry practice; more efficient control and review procedures for quality assurance, and so on. We need to look more holistically at all these elements, as well as the interactions and dependencies between them.

Through digitalisation and building information modelling (BIM), we may also modernise regulation in order to improve quality assurance in the process, from design to commencing the construction work.  This would make sure that we actually build what was intended. We will eventually be able to reap the fruits of digitalisation and both improve quality and efficiency for fire safety.

Do you think that the performance-based design will replace the prescriptive approach in the future?

The two approaches can and should co-exist. There are many situations, such as for simpler buildings, where there is no real need to use fire safety engineering methods. What’s important is that we need to develop prescriptive codes for those situations so that we have a sound standardized way of doing fire safety for all types of buildings.

Do you think that there may be a missing link between the two approaches in order for them to function together?

It would be good to do more research and create more feedback loops on how the different systems work in practice. We have to learn more from the industry to understand what went wrong, what could be improved and what was successful in a given situation. There’s a need to learn from both the fires that actually happened and those that could have but did not.

For example, in England there is a private initiative on fire safety in which structural engineers give feedback in incident reports. This means that if I, as a designer, encounter something that was a near-failure or a near-miss, I may write an anonymous report to give feedback to the rest of the industry. We currently don’t have these feedback mechanisms in fire safety, but I think that they are needed in order to improve our practice as well as the prescriptive and performance-based regulations and the links between them.

Smoke toxicity is taken into account in performance-based design. Do you think there is something missing? 

It’s a scenario for which we need more research. It may also be interesting to look at other objectives that may be relevant to performance-based design, such as property protection, business continuity and so on. These objectives may have potential connections to toxicity aspects and smoke spread in buildings.

Within life safety, we typically focus on the early stages of the fire where primarily the building content is involved, but what could be interesting is looking at robustness over time, and to learn more from fire instances. There is too little knowledge in that area.

About Michael

Michael Strömgren is a research specialist working for the fire safety consultancy company Briab in the field of fire safety engineering. He has degrees in Fire Safety Engineering (BSc) and Risk Management Engineering (MSc) from Lund University. Michael worked for four years with fire safety at the Swedish National Board of Housing, Building and Planning which is the governmental agency issuing the building regulations. At the agency Michael was the project leader of the last major revision of the Swedish fire safety regulations, introducing guidelines for fire safety engineering and performance-based design.

Michael specialises in fire safety engineering and works with research, education and specialised consultancy services. His work has included development of performance-based guidelines, third-party reviews and certifying national fire safety design reviewers. Michael pursues a PhD (part-time) at Lund University within fire safety policy making, regulatory evaluation & compliance, and outcome.

Michael is active in international fire safety engineering groups as a member of the Board of Directors of SFPE 2014-2017 and in International (ISO) and European (CEN) Standardisation. Michael is also the chair of the Swedish standardisation committee for fire safety in buildings (TK 181).