More and more public and private property developers enlist the services of VK Fire Engineering. But what does that actually mean? Must the extra requirements of the fire department then be followed unthinkingly? From calculations and simulation studies we see that some alternative solutions are also possible”, says engineer Erwin Theuns. Together with fellow architect and Director of Healthcare at VK, Stéphane Vermeulen, he explains some specific situations.

Erwin Theuns, Head Advanced Technologies at VK, is a specialist in - among other things - 'Fire Engineering'. Besides fire and smoke propagation he also simulates comfort situations and energy consumption in buildings and thus reinforces the aspect of sustainable building to which VK attaches so much importance. The simulations provide support in the application of the Energy Performance of Buildings (EPB) regulation whereby it is all a matter of using energy as efficiently as possible. This way consumption can be perfectly monitored and all kinds of situations can be simulated. Using the results of the simulations the design can be adapted and adjusted. VK also conducts all kinds of fire safety simulations. Erwin Theuns lectured at the University of Ghent on the subject ‘the spread of fire in buildings’. His research cell in continues to gain importance. Erwin Theuns: “We now see that our expertise in this field is increasingly in demand, for architects’ offices and property developers alike.”

INSIGHTS

Fire simulations are very diverse. They range from analysis of smoke propagation in buildings (applicable for the design of smoke and heat removal or RWA installations for short), via fire situation stability calculations to evacuation models assessing whether a building can be evacuated in time. Fire simulations can sometimes give new insights. The channelling of the smoke will depend on the form of the building, the ventilation systems, the use … Smoke can sometimes do strange things you might never have expected. That is why the design of an RWA installation is usually based on smoke simulations. The purpose of an RWA installation is to remove the smoke and the heat from a fire. This means that people are not prevented from moving during evacuation by the smoke and that the firefighters can tackle the blaze more easily. Dissipation of heat is also important if the fire is to be contained. Smoke ventilation may be vertical or horizontal. The vertical method is applied in atria where the smoke is sent upwards through smoke hatches or smoke ventilators. The horizontal method is used in car parks. It should be noted that Belgium is a front-runner in expertise in smoke ventilation for car parks. One not insignificant fact is that when there is a fire it is not so much the flames but rather the spread of smoke that is the problem. After all, most victims succumb to inhalation of smoke, not to burns.

WHEN FIRE ENGINEERING?

“Building owners can save bags of money through intelligent Fire Engineering”, says architect Stéphane Vermeulen. “Sometimes the Fire Department imposes additional requirements, for example a sprinkler installation and complete smoke and heat removal. From our calculations and simulation studies we see this is not always necessary. It often has to do with the fact that the Fire Department and the legislator - with reason, but not always sufficiently well founded - will tend to err on the side of caution. With our studies we can show scientifically that we can depart from the basic standards.” A standard solution is not always applicable in big, complex constructions. The regulations, the so-called 'basic standards', are at present mainly prescriptive or directional. They cannot possibly cover all types of construction or structure so an alternative approach sometimes has to be chosen: 'performance-based engineering', also called 'fire engineering'. This approach is all about looking first at what has to be done in order to guarantee an acceptable level of fire safety. The goals or objectives are expressed in performance requirements whereby scientific methods are used to show that these requirements are in fact satisfied. This approach involves simulations, calculations and thorough expert analysis. The 'fire engineering' method offers the designer greater architectural freedom, which is essential for some buildings. Examples of such buildings include the Salle des Pas Perdus in the Antwerp Law Courts, or the entrance to the Hospital of Our Lady in Aalst.

‘SIMPLE’ OR ‘STANDARD’

Building is a dynamic thing. New, pioneering techniques are used, and this sometimes also brings on changes in the treatment of fire safety. One example of this is the air seal of a building. On the one hand the legislator and the EPB standards encourage the builder to make the buildings as energy-efficient as possible: an energy-efficient building is an airtight building with as few air leaks and, ergo, as few losses as possible. On the other hand, however, the legislator writes in the 'basic standards' that technical shafts must be provided for ventilation, which is a considerable air leak. So regulation can sometimes be very contradictory. In 'simple' or 'standard' projects it is usually sufficient to follow the regulations currently in force. Erwin Theuns: “Certainly, these regulations appear to be sufficient for a good many buildings. The standards, at least as far as architects take any account of them, lead to good design. The standards are prescriptive, therefore easy to apply. If you know the rules, you’ll know how wide an evacuation passage or stairway has to be. You don’t have to make any complex evacuation calculation.”

DISCUSSIONS ON INTERPRETATION

Besides regional differences in regulations there are also differences in interpretation of regulations. One senior fireman may interpret an atrium as an exterior space while his colleague will see it as a part of the building. A substantial difference! Here too, VK can support your case scientifically. So, expert support is no unnecessary luxury for such matters.