Summary:

The building commission of the Pierre Elliott Trudeau Judicial Building began in 1989, then known as the “Federal Court of Canada Building”. In June of 2002, it became the task of Barman Swallow Associate to review the preliminary design of the building, and then analyses and implement any acoustic details that would be required to ensure the building achieved its acoustic specifications. This task was essentially an all-encompassing acoustic assessment, and would have to evaluate a broad range of acoustic criteria. The Room Criteria (RC), or background level, of each space had to assessed and managed if it did not meet a certain RC rating. The sound transmission class (STC) of partitions had to be analyzed in terms of the amount of sound transmitted through a partition. Similarly, impact isolation class, quantifying the impact isolation of a floor/ceiling system, was considered. The reverberation time (RT60) of a room was also an important factor to measure in the building, as well as the noise reduction coefficient. RT60 refers to the overall acoustic treatment of the space, while NRC only refers to the absorption coefficients of the space.

Solution:

Acquiring this data was an extensive process. Several calculations, measurements and models had to be evaluated in order to successfully approve the preliminary design and suggest any necessary acoustic treatments. It was ensured that all walls were to be built with the proper fill of absorptive material, there were no cracks or voids, and no back to back electrical outlets. It was also ensured that resilient channels were used in the necessary ceiling arrangements. Some of the rooms were to be constructed of concrete block, and thus sealings or silicone elastomeric coatings were to be applied to achieve acceptable STC performance. Doors impose a rather difficult acoustic problem in terms of sound isolation. To cope with this, specific door weights, constructions and frame assembly were suggested to accommodate the required sound ratings. The process of implementing all these features was required to be very comprehensive, as if any one aspect had been overlooked, acoustic requirements of the spaces would not be met.
Aside from the general acoustic treatments, there was a distinctive feature of the PET Judicial building that had to be attended to. The structure possessed two, 5 storey atria, each with unique acoustic requirements. The main goal was to achieve both acoustic comfort and speech privacy the atria, very difficult tasks to achieve in a large, open space with several reflective surfaces. Both these criteria were achieved by applying carpeting to the atria edges at each floor, adding a suspended ceiling with exposed metal mesh for sound absorption, installation of sound masking speakers. This, in addition to fine details for each floor exposed to the atria, contributed to the achievement of both acoustic comfort and speech privacy in the atria.

Overall, the acoustic treatment for the Pierre Elliott Trudeau Judicial Building was a very intensive, though well executed task. The team’s attention to detail and meticulous analysis of the building ensured that the combination of architecture and function were adequately met, if not exceeded.