Summary This report is part of a project entitled “Characterization of Open-space Offices and Coworking Spaces in Terms of OHS” (2018-0030), under the direction of Diane-Gabrielle Tremblay, professor at université TÉLUQ. The study, based on activity-centred ergonomics, provides an analysis of work in open-space offices and coworking spaces. The latter are portrayed as being conducive to spontaneous social interaction due to their open layout which, because space and furnishings are shared, establishes physical copresence and closeness among individuals. However, these interactions can be seen as costly distractions, especially for those who need uninterrupted time to accomplish their tasks. Noise is the greatest nuisance in open workspaces, with the most annoying being intelligible speech. The loss of acoustic privacy can impair concentration. While the characteristics of the work environment undoubtably have an effect on the experience of those occupying the space, the amount of control they are able to exercise can mitigate these effects. In this context, the study has four research objectives: (1) to identify the conditions and characteristics of spontaneous social interactions in open workspaces; (2) to understand how people working in open spaces manage their phone calls and videoconference meetings; (3) to identify the concentration levels perceived by those working in open spaces and the factors likely to influence them; (4) to identify the “occupancy strategies” that individuals may adopt to maintain their focus. The methodology was developed for the open areas of five coworking spaces and six organizations. The participating volunteers were first observed for two consecutive hours. Three types of behaviours were recorded in an observation grid (on paper) and an observation plan (digital format): (1) when the individual was interacting with others; (2) moving around; (3) initiating a telephone call and/or participating in a videoconference. At the end of the two hours of observation, each individual completed a questionnaire to assess their perceived level of concentration. At a given time, in semi-structured interviews, each of them were individually asked about their profile, what enabled them to stay focused, or prevented them from staying focused, their choice of which days they worked there and which workstation they preferred in the open area, whether or not they wore headphones, and about their behaviour that had been noted during the two hours of observation. The results from both studies came from 87 individuals in coworking spaces and 69 in organizations. They show that spontaneous social interactions in open areas are of short duration. In coworking spaces, the majority of interactions tend to be among work colleagues and concern work content. The remainder of interactions with others in the coworking space are usually informal. The interactions observed in coworking spaces are mainly among people seated at the same table. In organizations, all interactions are with colleagues, and there are as many concerning work content as there are informal interactions, with the most numerous (in both cases) involving movement. In addition, the results reveal that in coworking spaces, the majority of calls are scheduled and take place in dedicated phone booths. Those made in the open area are generally unscheduled, and the people making or receiving them do not consider them to be confidential or of long duration. In organizations, most calls are planned and take place in the open area, with workers choosing to make or receive calls there that they do not consider long, confidential or participative. In both studies, the types of call can determine where they occur: many people schedule them at home, to ensure an optimal environment. The results also show that people working in open spaces give their levels of concentration a positive rating. This perception is based on various factors: the conditions and requirements of the task, distractions and noise due to the presence of others in the open area, and the fact of working in a coworking space, in the case of the first study. Concentration in open areas also depends on the strategies employed by individuals: wearing headphones, the choice of workstation and which days they work there. The study provides food for thought to those responsible for the management, facilitation, architecture and layout of open-space offices and coworking spaces. In the case of coworking spaces, to better manage the dynamics of spontaneous social interaction, people’s profiles must be carefully considered and those who intend to join several spaces should be identified. One possible solution would be to adapt recruitment by selecting profiles according the characteristics of the space. Another solution would be to arrange furnishings in line with workers’ profiles. The physical copresence elicited by being in an open working area is not enough to ensure the types of interaction that will create connections and lead to collaboration. The managers of coworking spaces play a key role in that process. To adapt coworking spaces to the reality of phone calls and videoconferences, their characteristics (duration, predictability, recurrence, etc.) in existing spaces should be investigated in order to redefine the spatial framework. In the design of new coworking spaces, it would also be necessary to respect a number of criteria in the design of phone booths, in terms of soundproofing, size and equipment. Finally, it would be advisable to investigate the degree of acoustic privacy required, in order to redefine guidelines for existing spaces, and, to inspire the architecture, layout and location of future spaces. In the case of organizations, this implies granting workers some leeway. Materially, we encourage the wearing of headphones and the widespread use of fixed screens at all workstations. Spatially, we recommend ensuring that people who regularly work together are able to sit next to each other in the same office area, which would require a sufficient number of workstations and shared face-to-face working days. Timewise, we suggest consideration of a participative redesign of hybrid work, in which periods of equal importance alternate: face-to-face work to maintain the cohesion and efficiency of the work team, and remote work to accomplish tasks requiring a quiet, more solitary environment.