Main differences between prescriptive and performance approaches
Prescriptive approach: historic of Italian legislation, requires the designer to follow detailed and rigid regulations, without flexibility. This method is advantageous for its ease of application and the guarantee of uniformity in controls, but its rigidity limits the possibilities for adaptation, forcing the request for exemptions.
Performance approach of an engineering type (Fire Safety Engineering): is based on scientific simulations to predict fire behavior, thus offering flexibility and adaptability even in complex scenarios. However, it presents some challenges: it requires validated calculation models, high technical expertise of the designer and controllers, and considerable computational resources to manage the data.
Applicability of the legislation
For the fire protection design of a commercial business you can choose between two options: follow the traditional technical rule of the ministerial decree of 27 July 2010 or apply the Code updated with the new RTV V.8 of Ministerial Decree 23 November 2018.
Once one of the two regulatory paths has been chosen, it must be completed entirelysince they are alternatives and not complementary. There RTV V.8 it can still serve as reference even for activities that do not fall within its specific scope of application.
Case study: fire safety design of a shopping centre
The case study analyzes the renovation of an existing shopping center on two levels, with a maximum occupancy of 2767 occupants, 42 shops and a garage in the basement.
The fire prevention design was conducted using both the traditional legislation (DM 27 July 2010) and the Code updated with RTV V.8, highlighting how the traditional prescriptive approach is limited in its rigidity, often requiring exceptions and involving additional costs.
On the contrary, the Code offers alternative solutions that are more flexible and suited to the specific case, although it implies greater professional responsibility and competence on the part of the designer.
In the context of the project, they emerged technical difficulties for the installation of the system sprinklers and for the sizing of the SENFC systemas well as the verification of escape system. These aspects were managed through a engineering approach to fire safety, which allowed the evaluation of customized solutions to achieve the required performance levels more effectively than the prescriptive approach.
Designing with the Code also allowed measures to be taken targeted to the protection of life, such asexclusion of the positioning of vehicles in the porch on the ground floorwhich could have hindered safe evacuation in the event of a fire.
