Fire Science Show
Fire Science Show
226 - New Swiss fire safety code with Gianluca De Sanctis and Sofia Kourgiantaki
It is a massive effort to rewrite a national fire safety code around measurable risk, explicit targets, and cost-effectiveness. But sometimes, there are great reasons to do so. In this episode, together with Gianluca De Sanctis and Sofia Kourgiantaki we take you inside Switzerland’s sweeping reform, where a new federal law sets a maximum individual risk for life safety, ties property protection to a clear marginal cost rule, and harmonises practice across cantons. Together, we trace how the framework defines acceptance criteria, builds a shared “model code” of probabilistic inputs, and keeps prescriptive pathways for standard projects—only now grounded in risk-optimised measures.
You’ll hear how the system replaces vague equivalence with transparent math. Life safety is anchored at 5×10^-5 fatalities per user per year; if a building exceeds that threshold, measures are required until it doesn’t, regardless of cost. Beyond the threshold, optimisation is driven by the marginal cost principle and a nationally defined social willingness to pay, aligning fire with flood, transport, and earthquake risk policy. For property, the rule is simple and strict: do not spend more than the expected damage you remove.
While the code was being developed, Sofia put the method to the test in a retail centre case study using Bayesian networks and ASET/RSET. The model compared detection, sprinklers, and smoke exhaust while capturing occupancy, fuel loads, growth rates, system reliability, and fire service response. The surprising result: in a seven-meter hall, detection met the life-safety target on its own, and the most cost-effective optimisation paired detection with sprinklers, while smoke exhaust added little benefit in that geometry. The lesson isn’t that one system always wins; it’s that context and data should decide, not habit.
Switzerland didn’t stop at policy. A peer-review approval process, ETH’s advanced training in probability and risk, and a national model code make the approach usable and reviewable. The reform is in technical review ahead of political approval, with mechanisms for minor updates as evidence grows.
Direct links to the document:
- German Version: https://mitwirkung-vkf.ch/de/
- French Version: https://mitwirkung-vkf.ch/fr/
Also, there are 4 short videos in German, French and Italian that describes the new framework of the new codes:
https://www.bsvonline.ch/de/brandschutzvorschriften/projekt-bsv-2026/videos
A part of this shift in culture is also the new MAS in fire at the ETH, which you can learn more about in here:
https://mas-brandschutz.ethz.ch/
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Hello everybody, welcome to the Fire Science Show. Today I am taking you to Switzerland, where there's a big change occurring in the law systems. To start with, I my experience with the Swiss fire engineering is not very clear. But from people I know, they're very solid and pragmatic foreign engineers. I also understood that their code that they were using every day was about prescriptive-based code, so something similar that we would have in Poland. And then some time ago, I've learned that there is a major shift that you're ranking in the Swiss fire system, which is driving their whole framework towards risk-based solutions and kind of performance-based design. So a very, very interesting shift. And I know this was not only interesting to me, but uh to many of the listeners, because at multiple occasions people were asking me to try and cover this change in the podcast. So I did my thing, and I've invited two speakers who I've seen giving a keynote on this shift in the Swiss Spark at SFP Enro Corporation earlier this year. That is Gianluca De Sanctis from Bassler and Hoffman AG. And Sofia Kourgiantaki from Migros Engineering Solutions. And together they covered the development of the code and they covered the case studies which were used to validate or verify how the code performs in ReWorld projects. So in this talk, we'll dive deeper into the changes made to the Swiss Park code. But it's not meant to educate you on how the code looks like. This episode is more about a framework or things that you have to do, things you have to consider where you try to shift from a fully prescriptive-based solution to fully risk-based solutions. And so on. Also discussions when this makes sense, when this does not make sense. In fact, our new code is also enforcing prescriptive solutions for a simpler project. How to evaluate targets, how to evaluate uncertainties, how to make your whole engineering community ready for such a shift. Because you cannot do this overnight very quickly. It's a bit a long-lasting process which is still taking place in Switzerland. So all those things together, I think, is quite an interesting exercise on risk-based design and performance-based design. And how different is this from the world of prescriptive-based design that we still have in most of the places in the urban in the world. So given all that, I hope you will enjoy this episode. Let's spin intro and jump into the episode. Welcome to the Firescience Show. My name is Wojciech Wegrzynski, and I will be your host. The Firescience Show is into its third year of continued support from its sponsor OFR consultants, who are an independent multi-award-winning fire engineering consultancy with a reputation for delivering innovative safety-driven solutions. As the UK leading independent firewalls consultancy, OFR's globally established team have developed a reputation for preeminent fire engineering expertise with colleagues working across the world to help protect people, property, and the planet. Established in the UK in 2016 as a startup business by two highly experienced fire engineering consultants, the business continues to grow at a phenomenal rate with offices across the country in eight locations, from Edinburgh to Bath, and plans for future expansions. If you're keen to find out more or join OFR Consultants during this exciting period of growth, visit their website at OFRConsultants.com. And now back to the episode. Hello everybody. Welcome to Fire Science Show. I am today with uh two quests from Switzerland. Uh first, Gianluca De Sanctis from Bassler and Hoffman, AG. Hey Gianluca. Hey. And together with us, Sofia Kourgiantaki from uh Migros Engineering Solutions. Hi Sofia, nice to have you in the podcast.
Sofia Kourgiantaki:Hi, uh everyone. It's uh such a pleasure to be here.
Wojciech Wegrzynski:Yeah, it's a pleasure for me, and uh, everyone is looking forward to this episode. Uh I told you it was requested by multiple people on multiple occasions, no pressure here. So, what brought us in here is the new risk-based approach in Switzerland that's implemented, and you both have participated at different extents in this implementation and development. Uh, let's perhaps first start. How did you end up working on a new risk-based you personally and and what what was your role in the process?
Gianluca De Sanctis :Uh well, I'm a member of SFP Switzerland, and uh I was delegated to uh represent the SFP Switzerland in the stakeholder process, which is used to derive the the safety objectives which we want to address with the code, and also uh derive the acceptance, the risk-based acceptance criteria. And afterwards, I was part of uh a working group which uh derived the methods or the process uh for risk-based design. And Zofia?
Sofia Kourgiantaki:Uh so um I'm a fire protection expert, originally a civil engineer, and I work for Micro for the last four to five years. And Micro is um the largest retail company with um 500 retail stores and logistics centers and industry. And so I work in the department of in competent center of fire safety. It's an internal department that focuses on fire protection design and developing internal standards.
Wojciech Wegrzynski:And for the um risk code, I I saw that you've implemented case studies.
Sofia Kourgiantaki:Exactly. So recently I completed a Master of Advanced Studies at the ETH University in Zurich, and one of the central features was uh risk-based fire safety analysis using probabilistic modeling. So my master thesis was actually based on this case study that we conducted together with Gianluca.
Wojciech Wegrzynski:How practical? Uh was it good the the master's studies?
Sofia Kourgiantaki:Yes, it was actually great, and it was kind of the perfect opportunity for me to jump into the subject.
Wojciech Wegrzynski:Kind of a spin-off question, but I heard uh a lot of people say a lot of good things about that program. So I I just wanted to confirm firsthand. Okay, so why does Switzerland need a risk-based code or approach?
Gianluca De Sanctis :It's a good question because uh everything is fine with the prescriptive code we have now. So everyone can use it, uh, everyone is uh happy, not not really everyone, but from the terms of safety, we can say okay, the safety level that we achieve is kind of uh good. So there is really the question um why we should change this code. Um, and from the perception of the building owners, it is coming always okay. We have uh a safe code, but uh our costs for fire safety measures are are very high. So are they really efficient? And over the last 20 years, there is an additional pressure to the authorities to say, okay, do we have really uh an efficient fire safety design? And up to the 2015, they had hard time to answer this question because they didn't have a risk-based uh approach to it. And so they started to think about how they they want to improve the general framework, um, how to address safety in fire engineering or fire safety in general, and they came up also with this risk-based approach. So it was clear that uh we are moving to a risk-based framework, and it was long time not sure how it looks like because in our current prescriptive code it's stated that the safety has been equivalent to the prescriptive design. And there were also research studies conducted um also 10 years before, which showed that this strategy is not really appropriate to demonstrate uh which is not really a good approach to get this efficiency uh consideration into practice. So that's why there was also different uh research studies that showed different options, among others, this this uh marginal cost principle approach, which we implemented in the current code now.
Wojciech Wegrzynski:So, yeah, from your perspective as uh well, your company obviously manages a lot of buildings and most likely invests a lot of money into new projects. Uh, do you also see the risk-based approach and and this new code as an opportunity to improve efficiency? How does it look from the user of the code?
Sofia Kourgiantaki:Well, I think you just asked the right question because uh it's exactly what uh we needed that our company, this new methodology that uh FALK um developed, the Association of Cantonal Fire Insurance Companies, it's actually laid the foundation for risk management in Switzerland. And we are using also the same principle, the same methodology, not only for the public safety goods like people and property safety, uh so the building itself, we're using the same methodology also for the private uh safety goods, like our products, our stock of products, our facilities, and also the business continuity. We needed a methodology in order to ensure how our uh investments in fire safety, because the final resources are actually limited, how we can um invest them strategically where the greatest risk reduction can be can be achieved. It was a perfect opportunity for us.
Wojciech Wegrzynski:Well, opportunity, yes, uh for sure. Uh let's dive deeper into the code. Uh, we are having a very difficult task in here because we need to discuss what the risk method itself is and how does it work. But I'm also extremely interested in how is it incorporated into you know the whole ecosystem in the Switzerland, of which I have absolutely zero knowledge about uh making my job harder. But I I need to know how does it how is it implemented and uh how does it tie with with your existing safety approaches? Because you know, one thing is to develop a great uh methodology, but uh to implement it and turn it into a tool that actually works, that's a whole different story, and I want both stories in this podcast. So maybe first, what level of document is the new risk approach? Uh uh how exactly is it brought into the market?
Gianluca De Sanctis :It's uh a federal law now. A federal law, okay. A federal law which is um has an impact on every canton. So, like a national overall the canton zone. Exactly, yeah. And the cantons can't deviate from this federal uh law anymore. This is the case now that cantons can, in addition to the existing fire safety regulation, define additional measures uh to deviate from this federal code. And this cost not harm harmonized uh fire safety management across uh Switzerland, and this was also one motivation uh of the revision to get a harmonized dealing with fire safety across different cantons.
Wojciech Wegrzynski:Is it just one piece of law? Is it like there's a law and a second document that explains how to do it? Like what's the contents of the package?
Gianluca De Sanctis :It's one document, it has two parts basically. One part is the the legal formulation of what you have to do, and then you have uh also some um let's say um explanation how to deal with it with in in practical. So there are some kind of uh explanation how to to read this this legal document.
Wojciech Wegrzynski:Is it accessible to people outside of Switzerland or it costs uh one million francs to buy it?
Gianluca De Sanctis :Yeah, no, because it's a federal law, it's free. Okay um so you can uh download it. Now it's under technical revision. Okay, so it's also openly available. You can uh log in to the uh VKF and then you get the the doc comment in French and German. How useful? Um just kidding.
Wojciech Wegrzynski:You have to wait for the English version, yes. No, no worries, no worries. In the age of automatic translators will be good. Uh if a link exists, you can find it in the show notes to the listeners. Uh Sophia, the case studies and and the the documents that were a part of the process, is this also somewhat accessible or um well my master's thesis is accessible at the website of the ETH university.
Sofia Kourgiantaki:Um the case study itself was also financed from the Cantonal Fire Safety Company of Canton Vode, so it belongs to Canton Vode, so there is not a link accessible for that, but I have a big overview in my master's thesis.
Wojciech Wegrzynski:Fantastic. Good, good.
Gianluca De Sanctis :But on the FAUKAF website, you find also additional case studies or uh research studies uh which supported the whole development of the risk-based code.
Wojciech Wegrzynski:Okay, another another question. Does this approach completely replace the previous approach, or is this an addition?
Gianluca De Sanctis :Yes, uh, it uh replaces completely the current design approach, but uh I have to say it's not really uh the case that we just have a risk-based approach now, and if for every building you have to perform a risk-based analysis. This is absolutely not the case. Uh, it's rather that we have uh still we will have uh a proscriptive design where people who are not skilled as a fire safety engineer can apply easily the fire safety code and get a good um safety level with um very uh easy applying uh measures or measures which can be easily um taken from the code and then implemented in the design. But you have also the possibility to demonstrate your safety um by deterministic or a risk-based uh performance-based design.
Wojciech Wegrzynski:Is it in power for any uh construction in Switzerland or just from a threshold? And does it apply to new builds or refurbishments and uh all other repurposing projects?
Gianluca De Sanctis :No, it's uh really um an overall law for every building uh in Switzerland, except for buildings which are dealt in a different way on a federal basis. So, for example, uh if there are exist tunnel regulations um concerning fire safety from another party, uh then you have to take account of this regulation and then um the the fire safety regulations from the FAUCEF uh will not take that part in it. Which I believe already were risk-based. They are they are uh risk-based uh strategies uh for tunnel safety, yes.
Wojciech Wegrzynski:I had people praise those regulations in uh in my podcast already. Okay. So um we know how it is uh set, where is it? So let's talk about what's in it. Could you give me a quick overview of how the risk method that you applied looks like? You have like literally three minutes.
Gianluca De Sanctis :Okay. Um maybe I have to say about the framework. From the framework, we have defined in a stakeholder process uh uh the the safety goods we want to address. So it's uh we will restrict it on life safety and building safety, uh building property safety, actually.
Wojciech Wegrzynski:As in not collapsing or as in business continuity? As a damage prevention in monetary terms.
Gianluca De Sanctis :And for those two design objectives, we defined risk-based acceptance criteria, which are the basis for all design approach. So you can do a prescriptive or performance-based design approach. Doesn't matter. So you have always the same risk-based basis. The idea is that it doesn't matter which design approach you choose, uh, either a prescriptive or uh or a deterministic risk-based performance-based design, you will always fulfill the risk-based acceptance criteria defined in the stakeholder process. And either you show explicit compliance uh by a risk-based performance-based design, or you show implicit compliance by applying a prescriptive design or a deterministic performance-based design.
Wojciech Wegrzynski:Applying prescriptive means you already met the risk-based criteria by assumption, or is you have to demonstrate?
Gianluca De Sanctis :If you think of a building or a general building, you can make a risk-based design, and then you you get the optimal set of measures you have to implement. And if you have a lot of those typical buildings, then you can just say, okay, uh, we are dealing in a prescriptive manner. For the those types of buildings, we are setting those optimized risk optimized measures. And this is basically a prescriptive rule. So for the prescriptive design, we derived uh risk-based optimized uh uh measures, and we also know in what terms the prescriptive design is valid for. So if we deviate or a building deviates from this typical building setup, then we have to move to a risk-based or performance-based design.
Sofia Kourgiantaki:Sophia, from your perspective, uh it's actually um at Mikro we have retail stores with more of a standardized uh design. And here the prescriptive design actually makes sense. What do you we also um as a big portfolio owner, we also have uh our own industry and logistics? So for these special buildings, we need another approach. The prescriptive design uh isn't actually the right approach always for us. We need sometimes to precisely calculate the safety level and see which safety measures bring best to a risk reduction.
Wojciech Wegrzynski:Would you in that case perform some sort of risk assessment for the baseline prescriptive solution and compare it with uh with the target? I mean, I ask this because you explicitly said at the beginning that uh you wanted to escape the equivalency concept, but it are there buildings in which you would consider both and measure like the outcomes of them? Like uh how how do you switch from one mode to another?
Sofia Kourgiantaki:Okay, it it depends. Uh sometimes uh we take into consideration what uh the needs of of all stakeholders are, from the owner, for example, what the needs for this usage of the building is. Industry buildings, sometimes there are safety measures that in the prescriptive design that actually don't work out. You just see that they don't work out well. Yeah, like in a freeze storage, maybe a sprinkler system is not the best solution. Because it will it will probably react a little bit late. So you need to look into other kinds of uh fire safety measures.
Wojciech Wegrzynski:So basically you find the prescriptive code like that requires you certain things for certain spaces, but the variety within makes those things probably an inapplicable.
Sofia Kourgiantaki:Exactly. It's a combination of uh experience uh at work and the needs and taking into account all stakeholders. Um can we say the operative interests we also have to take into account the operative risk uh interests?
Wojciech Wegrzynski:But do the authorities treat the solutions that they have to treat the solutions in the same way, whether they come from prescriptive or risk-based. So this kind of also enforces uh the people who are commissioning their approving the building to to accept it, right? Because I that that that's also a potential trap in such a system.
Sofia Kourgiantaki:Actually, um competence and education is a really big part of it, also from the for the new legislation. Is uh competence is crucial, both for engineers who perform the risk-based analysis and uh for the authorities who have to review them at the end.
Wojciech Wegrzynski:Yeah. I mean, uh yeah, this is such a it's it's not a simple change to change one document in law, it's like literally shaking the whole you know approach. I I I love this. Uh yeah. Jean-Luc, I wanted to ask about equivalency. So obviously, if you have two pathways, I understand Sofia's point on when uh a company would choose one or another, that makes complete sense. But I like you you said explicitly that the equivalency concept did not lead to efficient design, but there's always you know some sort of need, or maybe not a need. Uh someone would like to compare the solutions coming out from prescriptive system, a risk-based system, and and see which one's better, worse. How do you treat that?
Gianluca De Sanctis :The level of safety now in the current code, in the current prescriptive code is defined by the prescriptive measures. And we can we have cases where we clearly see that the prescriptive setup is clearly not efficient. So if you are deviating from a non-optimal case and try to show equivalency by a risk-based or performance-based design, you end up with equal safety level, but you know that it is not really efficient anyway. So this equivalence approach is kind of flawed. So that's why we want to explicitly dealing the efficiency of the measures uh in our risk-based decision making. So in this way, we we ask for measures to be efficient. And in this way, we we set everything up from the prescriptive design to the performance-based design.
Wojciech Wegrzynski:But to know that the prescriptive measures are inefficient, okay, you can do it by your gut feeling and intuition and extreme experience that you you have in your work, and I respect that. But uh objectively you have to measure that. Where was there any you know a project to actually measure how much safety does the prescriptive give you?
Gianluca De Sanctis :Yes. Well, we we applied in different case studies before the revision and looked at the efficiency of um of measures like sprinkler system, uh, how much they cost, how much they reduce the risk, and then we judged are they efficient for the setup uh of the prescriptive code? And we saw that in some parts they are efficient and in some parts they are not efficient.
Wojciech Wegrzynski:Was there any specific projects at which the previous approach spectacularly failed? Like it was unsustainable. We have some massive airports and you know, extremely large shopping malls, for example, are extreme stress for me in my system. So I wonder if you had the same for you.
Gianluca De Sanctis :We saw that in some specific cases, um, some measure it's always that uh we have a very conservative approach. Or in general, it was too safe. That supported the perception of the the building owners that uh we have too high level of uh safety and we can reduce it to get a more efficient fire safety design. But we saw also that in some parts the the prescriptive design doesn't provide the optimal dissolution um as you would have in a risk-based design. So uh it's it's underperforming in in terms of safety. And in in this revision, we have a lot of uh deregulation, but we have also some parts where we have uh where we increase the need for measures and we um we get a higher safety level, but it's efficient to do that.
Sofia Kourgiantaki:And I would uh just uh I would like to add that it's uh sometimes for uh specific fire safety measures, it's clear that they are effective or they make sense, and sometimes it's just not clear. For example, what we did in this case study is we had a detection system, a sprinkler system, and a smoke exhaust system in the building, and we were not sure we need all of them. So in this quantitative analysis, we calculated the risk reduction for each of them and the cost effectiveness in the end, all these three systems, and uh, in the end, we decided for this specific building, the smoke exhaust system was not necessary, uh, definitely according to the new regulations. We wouldn't have to um install this as well. So it's sometimes it's not clear because uh the investment is too big, and you do a more precise analysis, a quantitative analysis to decide do I need this or do I need to do I don't need uh this one.
Wojciech Wegrzynski:To close on on the philosophy of the system, we'll move to case study in a second. Sophia, you mentioned that it came from canton insurance uh group or committee or uh of some sort. What what what's the role of insurance in all of this? Was like insurers supportive of this development?
Gianluca De Sanctis :The framework in Switzerland, how they deal with fire safety is that uh the cantonal building insurance have um a kind of governmental task. They have to enforce fire safety, but they have also to provide insurance for all the buildings, so they can't choose uh which building they uh they want to insure, they have to ensure all the buildings. But in this way, they can also say what kind of uh safety they they want. So it's basically uh a hand in hand. Um they have uh kind of uh um a task to ensure the the buildings, but they can also say uh what kind of level uh safety level they want. That's broken down into very simple pieces.
Wojciech Wegrzynski:Yeah, I mean I'm asking this because you said uh it was potentially too safe. I I get that. I I get this all the time in my tunnels, for example. Some things are over-designed, and they I always say uh you just need a specific level of safety in your building. It's not supposed that you escape the building, return to it, and escape again. It's like you have to be safe once. And and anything above it, it just provides you safety layers for bigger hazards, which are more rare by assumption. So I guess from an insurer's perspective, it's not their money they spend on on the investments.
Gianluca De Sanctis :So exactly. And and in this in this this framework, they have also the to prove because they are mandated from the federal federal body, let's put it like this. They are mandated from a federal body to ensure safety, and they have also to provide uh kind of uh a proof that they don't demand too safe solutions.
Wojciech Wegrzynski:Ah, okay. Wow, Switzerland is such an interesting country. This makes sense. Uh I would like to follow up also on the risk-based targets. So, because that's something I actually struggle with implementing risk-based approaches in Poland. I don't have many instances where I can do risk-based analysis in in my ecosystem, but actually in the world of tunneling, there are some spaces where through risk analysis I can demonstrate something or I can change a solution based on the outcomes of the risk analysis. However, I do not have risk targets in like explicitly mentioned in my code. I just I just it just says do risk analysis. Yes. You mentioned you have risk-based targets, what they are and how you got to them.
Gianluca De Sanctis :Um, we have two design objectives: life safety and property um building property safety. And for those two design objectives, we defined risk acceptance criteria. For life safety, we defined two criteria. One is that we have to ensure for every building in our portfolio maximal risk that uh is deemed to be acceptable. And beyond that risk, if you take this hurdle, then you can perform a kind of economic optimization of your fire safety measures. So that in this way we ensure that every building in our portfolio meets a kind of uh uh a safety level which is deemed to be acceptable. Is it one number for all buildings, or it's it's one uh number for each user. So every user has has a kind of uh um fatality rate, which we have to prove in design that uh that uh this this discretion is met. And beyond that, we can perform monetary optimization of the measures.
Wojciech Wegrzynski:If you meet the maximum risk, okay.
Gianluca De Sanctis :Yes, exactly. It's it's like uh a boundary condition that we have to take. And if we take this, then we can make economic optimization. And if we don't take this, we have to make measures not depending on the cost of the measures. So we have to to to get the safety level. Is this number written in the in the law? This number is written in the law, yes. What is the number? It's uh five times ten to the minus five per user per year.
Wojciech Wegrzynski:Okay, we we would be using one to ten to minus four, so you're having half of that. Yeah. Yeah, that that sounds uh that sounds uh reasonable.
Gianluca De Sanctis :And um the way we get there, uh to the economic optimization I will come maybe later, but the way to get there, we had experience in other fields that they are also dealing with uh such criteria, um such absolute risk criteria. And if you set them too high, so if your hurdle for safety is too high for this minimal uh safety level, then you you don't allow economic optimization. And one criteria or one qualitative understanding how to set this value was that we don't want to limit the economic optimization and it should be really uh stated in in terms of yeah, it's not too conservative. It's it's a high target but achievable. Yes, exactly.
Wojciech Wegrzynski:Uh and uh was there any consideration about the value of life, quality of life to establish this number?
Gianluca De Sanctis :For this number, not specifically. Um, it is basically we are in it to the On the safety level in other fields of safety. For the economic optimization, there the value of life or the social win is to commit social resources for safety is an essential part of the concept. Okay, that's one. You said there are two. So what's the other one? The other one is the marginal cost principle. It's in a framework with the marginal cost principle. So it's basically just cost and uh comparison between cost and uh risk reduction. So for building property safety, we defined uh for every monetary unit we invest into safety measures, we need one monetary unit of risk reduction. Uh-huh.
Wojciech Wegrzynski:So at least it evens out.
Gianluca De Sanctis :Yeah, that's the that was the easy part uh for building property safety. And when it comes to life safety, uh the thing is a little bit complicated because if you perform a risk-based uh design or uh risk assessment, then you get the expected consequences as definition um of risk uh in terms of fatality per year, for example. And then you have to compare this number to a monetary number of the costs. And for this, we apply a concept which is uh known as the social willingness to pay or to commit social resources. Uh, and interestingly, this number is also set by a federal organization for spatial development. So it's not this organization is not dealing only with fire safety, but it is also dealing with earthquake safety, with uh flood safety, and so on. And they set this number uh in a in a general term to uh as an efficiency criteria to derive efficient measures in each level uh of safety, uh in each safety field. And the idea is is quite nice because uh if you think about it, why should we spend one Swiss franc in for fire safety if this uh Swiss franc can be more efficiently used in in earthquake safety or in flood safety? So it will provide in this field uh a higher benefit for society.
Wojciech Wegrzynski:Yeah, I mean I'm I'm not exactly sure if this is the exact concept I have in mind, but Ruben uh once taught me a concept that it's very hard to establish the value of life in your country. It's an extremely difficult discussion to have in your country if you want to uh establish what is the value of a human life. But at the same time, yeah, society is willing to invest a specific amount of money to save lives. Like it costs you uh 100 million euros to build a hospital, you can build it. If it costs 200, then perhaps we don't. So through decisions like that, society already made its mind on how much it's willing to invest to provide this uh life safety and and this social willingness. I love the name. So so if you have someone that actually gives you the number to guide you and it's based across different disciplines, then it's awesome that you have that.
Gianluca De Sanctis :And uh, this is a whole research field actually. Um over the the 60 years, uh they have different approaches how to derive this number. Uh so if you go deeper in in this uh this topic, you find a lot of references um also in the national context, not only in Switzerland. So and also the OECD, so it's uh it's really an international level. They also uh recommend some specific values for different countries. And the numbers are there. Uh you come back of those um organizations and those methods. It's really the case what you want as a stakeholder, what do you want to achieve. And it took us two years in the stakeholder process. In this process, uh we we had uh over 20 stakeholders participating in discussion, what level of safety and what numbers we want to set for the new code.
Wojciech Wegrzynski:Perfect. Um Sophia, so in your case studies, you probably had to calculate all of those. I I assume that was the outcome. So maybe let's introduce the listeners to the case studies that you've run and talk about how you have applied this methodology and what were your findings. Let's start with with what they were.
Sofia Kourgiantaki:Okay, uh, well, it was a research project. We decided we our project team was uh Gianluca, me because I had the interest for my master's thesis as well. It was initiated by my colleague and mentor Thomas Laschett and under the technical supervision and guidance of Gianluca, and uh it was also financed from the insurance fire insurance company of Canad uh VOD, as I said before, and uh represented by DDA Gignard. So, Migro, as a large portfolio owner, was willing to initiate also this research project. It was one of our shopping centers. So the aim was to apply this new methodology and answer key questions that are um important to both planners from our point of view, uh, or the owner, and to the authorities as well. So, from a planner's perspective, uh it was critical to identify the data availability, what data do we need, and how accessible it is for us. Um, also the competencies, which skills and tools are required to conduct a quantitative analysis, a risk-based analysis design. How robust this concept is, how stable the the approach is when the conditions change, for example. And uh finally, how well it integrates into the planning process, how does it influence the project development overall? So, from the authority side, uh the focus was on the feasibility of the proposed design and to evaluate the plausibility of the overall approach. So, as I said before, it was kind of the perfect opportunity for me for my uh master thesis, and these were the key questions of the thesis as well. And uh we conducted this risk-based performance-based design for the risk modeling. We use Bayesian networks. This is a graphical model that represents the probabilistic relationships between variables. We it's um like a simple fault tree, but unlike one, we have multi we can reflect, we can portray uh multiple dependencies at once. So it's a more complicated model, but we can include a lot of information like uh the fire protection fire safety measures we want to analyze. The ones I mentioned before, the detection system, the sprinkler, and the smoke exhaust system, the effectiveness of these measures, like the probability of failure or the probabilities that they are inactive, uh the fire brigading's response, also the fire development, the fire characteristics, such as the fire growth rate. We took into account multiple fire growth rates with their relevant probability of occur occurrency in retail buildings specifically, and also building usage characteristics, like the occupancy density is different at night and in the middle of the day, or maybe in a very rare occasion, such as Christmas, we took all this different information in this we took into account in the model in the modeling all these characteristics. So, in the end, we calculate the risk for a life safety and property safety for the extent of damage. We also used uh modeling and we did we performed A set airset uh comparisons. Um we I calculated the available and required safe aggressive time multiple times for different scenarios, it was spread, and for the building, we did we took into account the extent of damage in the building. So we conducted the whole probability analysis and consequence analysis, and we used the risk acceptance criteria, the way Gianluca described them before, and to realize at the end that to achieve this acceptability line, this minimum acceptability line for the people's safety, we just needed one of these three technical measures. For example, the most the cheapest one, uh the detection system in this specific case. But uh with the marginal cost principle, we also need to apply more. And in the end, uh a combination of a detection system and a sprinkler system for this building was uh the perfect combination, we could achieve the the greatest risk reduction, and it was cost effective.
Wojciech Wegrzynski:So basically, with your first approach, any of the three would give you the cut threshold of five to ten minus one five. Uh so you would get the baseline, and uh here you are in the economic optimization, and then using the marginal cost principle, you basically established that it is efficient to add another measure in this case, uh, the sprinkler system, but the gain is not enough to justify installing the third one, which was the smoke control in your case.
Sofia Kourgiantaki:Yes, and that was because uh in the specific building, it was an old industrial building with a ceiling height of seven meters. Yeah. And it was kind of obvious that the smoke exhaust system in this specific case was not very effective. But in another building, uh like the standard shopping centers that we have with four meters height, it definitely is something we have to consider, so it's not very obvious. So it was a specific situation that gave us these interesting results, and we could consider reducing the um fire compartments, so we could maybe uh don't have a sprinkler system in the building. You can also see uh where you can apply different safety measures and which factors uh um affect the results.
Wojciech Wegrzynski:Fantastic, really, really good. This is very interesting. Gianluca, from the risk model perspective, Sophia mentioned she used Bayesian networks. Is the tool also defined in your law, or it just says you have to do risk analysis? How deep does it go in defining how the risk analysis should be performed?
Gianluca De Sanctis :Uh we set rules for the risk-based approach that you have to follow. For example, you have to follow the rules of probability theory. So you can't invent, for example, or you can't use, for example, the greater method, which is our index uh-based uh method. Anymore, so you have to define uh your system in the means of uh probabilities and quantify all the uncertainties. And this was one is one example among different uh rules. And we also defined in the in the document some basic parameters for the risk-based design. It's called the model code. The model code defines basically the parameters you have to consider in in your risk-based design, uh, but you can also deviate if you know it better.
Wojciech Wegrzynski:Do you define the trustworthiness of the sources that tell you you know better? Like, can you do you have to base it on peer-reviewed uh research? Do you can you base it on a podcast episode? I don't know.
Gianluca De Sanctis :For the podcast, I'm not so so sure. I I would not recommend that. Like well, you can deviate in uh in a specific project. So if you if the model code is not giving you additional information or basic information on on some specific point and specific issues we which you have in in the project, then you can also deviate. And then you can uh go to the literature. Um, I mean then you you enter our daily engineering life, how you do you combine different information, put them together and um assess or perform the whole design. But if you are doing so, if you deviate, then you always have to um also to model the all the uncertainties in your deviation appropriately. So that means that you have to perform sensitivity analysis and also parametric analysis and so on.
Wojciech Wegrzynski:Is there in the end some uh responsible person, an officer of some sort that approves or disapproves that?
Gianluca De Sanctis :Yes. In Switzerland it's quite a good system. Uh we established over the years. So we have a kind of a peer review system. So every design, prescriptive or also performance-based design, is getting through the authorities and they have to uh approve the design. And this was a large discussion how the authorities can approve uh risk-based design, because the knowledge how to perform risk-based analysis is not that broad in Switzerland yet. So um this is uh one of the major tasks we have also to face in the future. But there are also existing some specific solutions to it.
Wojciech Wegrzynski:Yes, if you already mentioned that the competencies is critical if you want to establish system like that, not only within the designers but also within the authorities who have to go through that. Uh in the modeling itself, those have to be deterministic. I assume you said the no indexing methods, uh etc. But do you specify approaches like ACR set or okay?
Gianluca De Sanctis :Um ACR set is one way to uh assess the consequences uh which you have to consider in the risk assessment. We don't specify how you you have to do um AZR set analysis because this is um we don't we didn't want to write a textbook how to perform your design. This is uh built in another part in a different code, but we wanted to just set the main driver which which drive the risks. So, for example, we specify occurrence rate in the in the code, um, in order that everyone is doing the same to specific occupation or it is uh tied to the specific occupation classes, um and then you have the possibility also to adjust in um in a way to your project-specific object. And then we specify, for example, uh also the um fire spread rates or the probabilities which are associated with fire spreading, uh like fire growth time, a completely probabilistic distribution of the fire growth time. Um we specify, for example, uh the burning behavior of your fire load, um, the fire load itself as a probabilistic distribution, and so on. So if you look in there, you find a lot of information about how to describe the uncertainties in your system. And starting from the the fire occurrence over the efficiency of the measures, but also about model uncertainties and also fibergate intervention, um, is also handled there.
Wojciech Wegrzynski:So if you are when applying this in practice, uh, how useful was there? Did you have found some of them which were problematic to you? Did you have to seek further? What's your assessment of those?
Sofia Kourgiantaki:Uh well, actually, it was very interesting because at the time when um I was conducting the the uh the case study or the probabilistic analysis, John Luca was also parallel developing this model code, these guidelines.
Speaker 2:Uh-huh.
Sofia Kourgiantaki:So it was a direct apply, and it it really helped me to understand why we need this approach in every single step of the way of the analysis. Why do we need these spreads? Why do we need these distributions in order we had to uh model these um uncertainties?
Wojciech Wegrzynski:I mean, you you've mentioned some of the most difficult to find, like occur occurrence rates, efficiency factors for uh systems. Wow, this is like this is a very difficult statistic to have a very solid, like science-based grasp on. Almost like I would risk this is almost impossible to get at the level we would like to have it. So I I but I I see a value if this is defined in the code, you may not be closest to the truth, but at least everyone is lying at the same rate. Exactly.
Sofia Kourgiantaki:Exactly.
Gianluca De Sanctis :And we are, I mean, to to today, uh our today's approach is that we in a performance-based design, we just set a specific scenario, and then we are performing our uh performance design design based on this scenario, and uh selecting this this uh design scenario is is complicated as well, and you can't also uh state in the in the in the codes. There are codes that state you have to consider this specific uh scenario, but uh in some times um it's okay, and in some times for some buildings, um you can't apply this scenario because it doesn't make sense. So um and in this way you have the same problems actually. So uh and what we we did also in the in the model code is that we relying on the on on data, so for example, the occurrence rate in Switzerland, we have uh a pretty good understanding how often a fire occurs, because we had data from the insurer and they uh track every fire because every fire with uh financial damage, they they uh assess because they insure it. So uh we have very good databases for this specific topic, but you you're right. In in other parts, for example, uh in the efficiency or the effectiveness of some kind of fire safety measures, we had less good data, and then we had to make some estimates also, but always in the context that we are not interested in having a very exact or the precise risk assessment, because the the aim is having a robust decision about what kind of fire safety measures we have to intake. So in in this way, we can say, okay, if you are using the those uh numbers, everyone is doing the same stuff. So everyone doing is uh is wrong, but uh everyone doing is the same stuff. Everyone is wrong at the same extent, exactly. But it's not really worse than uh compared to uh a deterministic performance-based code where you specify some design criteria. So uh yeah, that that was a trade-off.
Sofia Kourgiantaki:Yeah, I'd also like to add it's exactly that what Gianluca said. We have these uh factors where we are uncertain in the model. So what can we do? We can take a more conservative approach on them, we can play with the model. I had the opportunity to play with this modeling and see how they affect the outcome. Also, the the conservative approach, how does it affect the outcome? And in the end, I have a robust design which is not so much affected from its of its characteristics.
Wojciech Wegrzynski:I found it very important. Like if I compare it to the Polish context, you also don't want engineers to compete on design fires, you don't want you know engineers to compete on suit yield. If I have a suit yield of 0.1 and someone else has 0.05, and they have half of the system I do, well, that's kind of obvious, isn't it? Right? Uh but it's kind of nuanced, and the end client may not recognize the difference, you know. And I my system is perceived as the worst because it's so much bigger. What's the reason? Well, there is a reason, but they perhaps never had a chance to actually fully comprehend the difference. So I I appreciate that, yeah. Yeah. Okay, so uh so uh the final question the is this all you said it's in the comments, so I assume it's not yet in power, or is it in power?
Gianluca De Sanctis :Now it's uh under technical uh revision. Uh so everyone in Switzerland can um say, okay, yeah, this part of the of the new fire safety code is uh is wrong or it has to be be improved, or um yes. So that's the the technical revision is going up to the January 15th, and then it's going to the to the Faukaf, and then we have to revise the code, and then it's uh there is a political uh review, and then from 2027 it is in no just in time for a Geneva conference. It's uh right before the Geneva Conference, the SFP. Uh Europe Conference. So that will be a very good celebration. Does it have to go through some public vote or something?
Wojciech Wegrzynski:What was the political pathway for the project?
Gianluca De Sanctis :There is a political um instance that uh revised the code. So there is a political approval needed for getting through the whole process, yes.
Wojciech Wegrzynski:While doing that, are you still working on uh some sort of improvements, or you're still running case studies to see how to implement it, or maybe you can apply some of it through derogations or something?
Gianluca De Sanctis :In the current code, we are not allowed to apply the risk-based design. Hence, you need the new one. Yes, that's but for only for uh public safety goods. But for private safety goods, uh, for example, like Sophia is dealing with um business continuity and so on, uh, there we can also uh deal with uh this risk, and then it helps also to look in the model code, see um what are the the effectiveness or the raility of the uh measures, and then we can um incorporate this um these numbers in the in in the risk assessment for private safety goods.
Sofia Kourgiantaki:It's um uh thank you, John Luca. It's uh it's uh what I also mentioned in the beginning. Uh we have now the foundation for its risk management, and we are trying to implement it also for the private safety goods.
Wojciech Wegrzynski:Have you already considered some sort of revision cycle or like a living document for a pathway for this?
Gianluca De Sanctis :Well, fire safety codes are revised every 10 years. This is quite long, but minor revisions can be taken um also in a short shorten period. There is uh a committee who is dealing with um minor changes in the codes. Yeah.
Wojciech Wegrzynski:Yeah, so just for SFP Tzurich in 2037, good. Exactly. And uh well, one final question to Sophia. Did this experience change the way how you approach your projects in your everyday job? I think exposure to risk uh changes your perspective even on the prescriptive code.
Sofia Kourgiantaki:Definitely, it was such a valuable experience. Also, uh, I learned new methodologies. This uh actually, this Master of Advanced Studies at the ETH uh was a big um opportunity for me to gain knowledge in all engineering methods in fire safety as well as probabilistic modeling. And on my everyday job, definitely, I definitely implement the things we I learned, and we are also um on this uh methodology. We as I said, we work on it on the for the private safety goods, and the results are very, very interesting.
Gianluca De Sanctis :This was one of the strategic strategic components, this MIS at ETH, uh, where we we in 2015 we we saw that the direction is going to risk-based codes, and we thought, okay, um, how we we can ensure the competency of people. And one way to to get the basis is uh by education, and this is a very important step. And the the the whole uh Master of Advanced Studies, it's only it's not a fully master, it's a master of advanced studies, has uh five models, and one model is specifically uh treating uh probability and statistics and risk-based design and um performance-based design in a in a general context. And one of five models we dedicated to just risk-based design because we we we realized that we need this uh the knowledge for the upcoming fire safety engineers in Switzerland uh of this risk-based design.
Wojciech Wegrzynski:And now I fake being surprised you've strategically done this like as expected. No, but this is a great decision. Like I think it was Professor Arnold Dix who told me he loves the Swiss approach to risk the most because it's very, you know, like efficient. I um he perhaps used the word efficient, but I think efficient is what he had in mind. And and I agree, this is it's not just about writing a code, it's about changing the system and acting on all of the fillers. If you if you did change the system and you did forget about educating new generation of engineers who can use it, not good. If you change the system and you have not said what kind of tools you want, not gonna work. No risk-based targets, you're gonna have a horrible time. Yeah, uh allow people to choose their own occurrence rates, it's not gonna work. So I think uh there will be things that work better and worse in the system for sure when you start applying it everywhere. And I guess this this revision cycle gives you opportunity to improve, but I think your starting point is is really, really sound and good. And and congratulations to everyone involved in this. Uh, I remember at the SFP Edinburgh conference there was uh a quite lengthy and and quite challenging questions and answers session, which uh you have defended yourself quite well back then, but I'm also pretty sure we have answered a lot of those questions in a more elaborate way in here. So I'm I'm extremely pleased with that. So I leave the last words to you.
Gianluca De Sanctis :So thank you, Wojciech, for this opportunity. I think um this this uh also from my point of view, uh when I could reach how fire safety should look like, I think the Swiss approach is going in the is a very uh a close point to my perfect world of risk-based design and also how uh in the future we have to deal with uh fire safety. So it's uh it's a very nice development in Switzerland. And um, I I loved the that we we get the opportunity to to show the audience now to um how can it be done?
Wojciech Wegrzynski:And there are a lot of other opportunities to get into in this uh the only thing that worries me, which is not a worry for you, but the thing that worries me is could this be implemented in a place which is not Switzerland? No, I I I mean you you know you know what I mean. Like yeah, all the puzzles that are in place that make complete sense for you. I see you know traps, uh holes with spikes, uh, you know, waiting for me if I wanted to do like it's it's way beyond implementing a risk code. So but you already did actually.
Gianluca De Sanctis :Yeah. Uh if you look at the structural fire safety code, uh Eurocode AN 909112. This approach, um, which we want to uh set in fire safety now for in general, this has been already done in structural fire safety engineering. They derived a deterministic design from probabilistic criteria. The deterministic design is used to derive tabulated data uh for architects, which can um for standard buildings, they can just pick the numbers from the tablet data. But and what a lot of people don't know, those performance criteria stated in the Eurocodes, they are derived for by the marginal cost principle. So it's exactly this this whole setup, and uh in the background you have also a model code which specified all the uncertainties in the structural engineering. So, in this this kind of way, this this whole approach is not really new, it is really inspired by the structural engine and engineering uh approach.
Wojciech Wegrzynski:I agree with you, but still when you zoom out from one branch of fire safety, like structural, into the entire fire safety, you suddenly can replace the passive fire protection through sprinklers or perhaps by combination of smoke alarm and vents, if you can prove through your analysis that that's the efficient way, and suddenly you are touching economical incentives of so many players around. That's uh that that that that's a completely different anyway. Um we've deviated so Sophia, uh what's uh what's your final message to the audience?
Sofia Kourgiantaki:I think um to your point before I I think it cannot be implemented one-to-one, but I think it definitely has potential, this uh risk management approach. And it enables tailored solutions for our buildings be beyond prescriptive regulations and as I said, targeted investments in fire protection with uh truly cost-optimized solutions. That's actually my point. It was um such a pleasure to talk about it, about um my work on this, and it was just a small part in this big project. So, yeah, it was such a pleasure to be here today. Thank you.
Wojciech Wegrzynski:No part is small. Thank you, thank you guys for for coming to the Far Science Show. Thank you.
Sofia Kourgiantaki:Thank you.
Wojciech Wegrzynski:Yeah, that's it. Thank you for listening. So, what do you think about the changes to the Swiss Parco? Do you think this could be implemented somewhere that is not Switzerland? I really, really wondered uh at the end of the episode whether this is something that he could just translate to a different country and apply there successfully, because it's not just about picking a risk methodology. It's not about, you know, setting your law requirements that force you to do a specific pathway in your project. It's also not about just finding equivalency between solutions. Uh it's a lot, a lot more, as you have heard in this episode, it's about finding prescriptive solutions that work based on the risk principles. So uh following the Prescriptive pathway actually fulfills the risk-based goals. It's about setting the targets, setting the goals in such a way that they provide sufficient level of safety that they are happy with, but at the same time do not kill the economic incentives to optimize. Look for better solutions. It's about promoting fire solutions that uh actually make sense economically. So you reduce risk when when it makes sense. I really, really like it. But so many things that you have to have in place to enable this. And I think uh in in in Switzerland, the culture is actually very good to apply this. I I wonder if you could translate the culture of the risk-mease method. I'm keen to observe how will they apply this method in practice, how will it evolve over the years, what will be the changes, what will be the feedback of the real users. I'm I'm I'm also quite happy that uh while developing the model, they already do case studies like the ones that Sophia presented, because this allows them to uh double check everything while it's being built. But uh the real world will bring so many more case studies that they will learn a lot more about the implementation of the method. I'm looking forward to learn what they learn from from that aspect. But for now, I'm really amazed about uh how this new approach was developed, and I am looking forward to to see it in practice. If you'd like to check it out, uh there's a link in the show notes and it's in German and French, but in the age of AI, I don't think that will stop you if you are curious enough to see uh what's inside, and let's see how where we get with that. If there are more news from Switzerland, if there are some experiences from implementation of the materials, you can be sure that you will find them in the fire science show as well. Thank you very much for being here with me today, and I'm looking forward to see you here next Wednesday. Thank you, bye.