BIMAE

Today, in major urban planning projects, the acoustic study is normative. It seeks to deal with the sources of noise pollution independently of each other, without having a global understanding of a soundscape, which is essentially variable according to the hours and uses.

Environmental Acoustic BIM – BIMAE aims to respond to this problem by modeling the acoustic landscape in the future state of completion of a project from the design phase to rendering. By aggregating all pollution information, from transport noise to human activities over the course of a day, it thus makes it possible to size the acoustic protections in the architectural layouts in relation to the needs of the project.

Acoustic legislation in environmental matters has profoundly shaped the methodologies and tools of the profession

Indeed, the standard sets different criteria for protection against nuisances according to the sources of noise observed (transport routes, noise from human and neighborhood activities or construction site noise). In order to meet these criteria, the profession has therefore mainly focused on solutions for protection against nuisances, taken individually and on the basis of acoustic observation measurements. Consequently, as this method does not make it possible to predict the sound levels of an urban planning in the future state of completion, the acousticians are forced to size maximalist acoustic protections that are very engaging on the architectural level to guard against nuisances.

French legislation

• Noise from land infrastructures: decree 95-22 of January 9, 1955 relating to the limitation of noise from land transport facilities and infrastructures. They must not exceed a certain level of noise observed inside the dwellings.

• For the noise of human activities, the framework law on noise of 1992 and its implementing decrees, the acoustician ensures that a criterion of non-emergence is verified set from the quietest half-hour observed day and night

• For building site noise, the framework law on noise of 1992 and its municipal application decrees, the contracting authority has an obligation of means in order to limit the emergence of noise from construction site noise.

If this normative approach is necessary not to reproduce the levels of noise pollution reached in the 70s and 80s harmful to health, it is insufficient when it comes to reflecting on the acoustic coherence of urban planning and to meet the expectations and user needs.

Far from being only an engineering protection against nuisances, acoustics contributes to the coherence of urban planning. This engineering constitutes a real tool for reflection on the creation of a harmonious soundscape when it is integrated from the first phases of the projects. Nevertheless, its techniques and methods must still be able to predict a soundscape in the future state of completion and its tools must be able to guarantee successful collaboration with architects and urban planners.

Our solution: environmental acoustic BIM – BIMAE®

Environmental acoustic BIM is a 4D temporal modeling software of a current soundscape or in the future state of completion. It makes it possible to visualize, in dynamics, the sound evolution of an urban planning over the course of the day. Depending on the urban data of the building and the uses of the buildings as well as the topography of the town planning, the BIMAE aggregates the various sound emissions possible during a day to simulate the typical acoustic landscape. The information on the different sound emissions is based on:

• On-site acoustic measurements

• A statistical approach, the Urbanistic Noise Map®. Indeed, in order to consolidate our acoustic measurement results and thus be less dependent on the intrinsic variability of a soundscape, we cross-check our observations with our database.

• Information to take into account the variability of the soundscape, taking into account the different sources of noise, namely:
  • The hourly noise level of the adjacent transport routes according to their classification and their traffic;
  • The sound level of nearby human activities, based on the expected density of people per m2 according to the type of activity and the schedule of occupation of the spaces.

Urbanistic Noise Map®

The Urbanistic Noise Map is a project developed under an ADEME research contract. It aims to establish a correlation between the different types of town planning and the noise level, in order to be less dependent on specific measurements in the definition of the criteria for maximum permissible sound levels during the day and at night. This tool, which we are constantly updating, is based on thousands of days of measurements relating to thousands of urban configurations encountered. Town planning is first identified according to the density of the urban fabric, its proximity to the transport route and the type of route (from the motorway to the local road).

Following these campaigns of measurement and identification of the different types of town planning, we established a correlation between the different town plannings and the criteria of maximum admissible sound levels expected day and night. Therefore, we establish an acoustic classification of zone determining, thanks to our statistical approach, the criteria of maximum acceptable sound levels day and night. By consolidating our measurements with our statistical approach, we thus reduce the risks of dependence on the intrinsic variability of a soundscape.