Working in an office environment entails various activities. Communication on the phone, social interaction and meetings produce not only sound, but are also in need of a good speech intelligibility and therefore in need of good room acoustics. Difficult performance tasks are in need of different acoustic conditions. Areas with a more silent environment are needed with a minimised level of distraction from surrounding activities. Areas with a high level of interaction provide workspace for the purpose of teamwork. Different activities require unique acoustic conditions. Before creating a new activity based design in retrofit buildings, the existing acoustic environment is carefully measured. The acoustic qualities of the existing facilities as well as the actual behaviour of the existing population of the building are both measured. The sound insulation of the existing walls is defined as A-weighted standardized level difference DnT,A, measured according to the Dutch norm NEN 5077 (similar to ISO 140-4). The room acoustic parameters are defined by the reverberation time T, measured according to ISO 3382, and the spatial decay rate of A-weighted SPL of speech D2, S measured according to the norm ISO 3382-3 for room acoustics in open plan offices. The level of speech privacy is interpreted out of the combination of A-weighted sound pressure levels of speech Lp,A,S and the average A-weighted background noise level Lp,A,B per position. During a representative week of working hours the sound levels are being measured on different locations in the open plan office. The sound levels are measured in equivalent sound levels Leq, 5min and maximum sound levels Lmax, 5min. To gather information about the character of the sound, sound fragments are also recorded based on a trigger level. Defining the acoustic environment of (semi-)open plan offices based on building measurements and noise level measurements produces a solid foundation for designing a more sustainable office environment. Often the new design leads to activity based office plans where diverse activities are projected in a (semi-) open plan office. This is illustrated with a practical example of an engineering project.
Vellenga-Persoon, S., & Höngens, T. (2015). Acoustic measurements in retrofit buildings lead to a sustainable design of a (semi-) open plan office. In Energy Procedia (Vol. 78, pp. 1641–1646). Elsevier Ltd. https://doi.org/10.1016/j.egypro.2015.11.243