In recent years, attention has been focused on the utilization of historic row houses in Kyoto for commercial and accommodation facilities. For such utilization, it is necessary to comply with building fire regulations, but for large openings, fire prevention measures suitable for traditional designs have not been developed. This study focuses on the development of wooden traditional style sliding storm shutters with the performance of 20-min rated “fire door”. Studies have been conducted to determine specifications of the “Door part” (panel and sash) and “Movable part” (fitting between doors or between door and door cheek/pillar/lintel/doorsill) to establish integrity of the whole shutters to prevent flame penetration. Following possibilities are considered as the major cases of the flame penetration.

(Ⅰ) Flame penetration through joints or by charring.

(Ⅱ) Flame penetration through gap produced by falling of components or through an opening produced by the move of components.

(Ⅲ) Flame penetration through gap produced by the deflection of components.

　The study consists of the following four stages. All studies are based on furnace tests.

1. Examination of the integrity of various candidate specifications of the “Door part”

2. Development of 20-min rated small windows with two wooden sliding shutters

3. Development of 20-min rated doorway with two wooden sliding shutters

4. Increment of the number of shutters to extend the opening width

　The study has finally concluded the following design instructions to achieve 20-min rated fire doors with wooden traditional style sliding shutters.

(1) Door part (panel and sash)

・ Timber, 30mm thick panels and Western Hemlock, 36mm thick sashes are enough to prevent flame penetration.

・ The maximum width of a door is 1016mm.

・ In case the shutters are located in a doorway (opening-height of doorway is higher than small windows, 1095mm, and shorter than 1820mm), middle sash is attached to the door to prevent producing of the deflection of panels.

・ Tongue-and-groove joints are used, and reinforcing plates are attached at joints of panels from the back-surface.

・ Panels and sashes are fixed by reinforcing plates with nails (at sash-side) and screws (at panel-side).

・ Joints in sashes are fixed by screws. Shiplap joint in sashes at heating surface prevents flame penetration by charring.

(2) Movable part (fitting between doors or between door and door cheek/pillar/lintel/doorsill)

・ Gap closer is used in butted part of door cheek and door, which has no gap when doors are closed.

・ Intumescent fireproof tape is used in clearance between doors and between door and pillar/lintel/doorsill, which have gap when doors are closed.

・ Fitting of L-shaped incombustible stopper to the groove of the lintel prevents falling of door by charring of the lintel.

・ Dimension of door cheek, lintel and doorsill is set enough to prevent falling of door cheek, lintel and doorsill.

・ Throating member which has enough height to prevent flame penetration is set in doorsill in the back-surface.

・ Doors are locked by sickle lock and screw fasten locks to prevent doors from moving.

　Activity-based working (ABW) is a new working style that aims to improve the workplace productivity of office workers. In ABW offices, the work engagement of office workers is expected to improve as workers shift to a working style that allows them to think and act for themselves. The spread of COVID-19 has led to an increase in new ways of working that combine office work and telework. Recently, the introduction of ABW in a huge single-floor space, called a mega plate office, has attracted attention as a way to further increase the effectiveness of ABW. Few studies have been conducted on workplace productivity in mega plate offices with ABW. However, to the best of our knowledge, no case study has been conducted that directly evaluates the relationship between work engagement and workplace productivity in mega plate offices. Therefore, this study aims to evaluate the impact of the indoor environment of a mega plate office on the workplace productivity of workers, the relationship between work engagement and workplace productivity in mega plate offices, and the impact of mega plate offices on the workplace productivity of workers in a working style that combines both office work and telework.

　Indoor environmental measurements and questionnaires were conducted in a previous office, a mega plate office winter with a traditional work style, and a mega plate office summer with a work style that combines office work and telework.

　The percentage within the thermally acceptable range was higher in the mega plate office summer than in the previous office. The average CO2 concentration was low in the mega plate office winter. In addition, the average CO2 concentration was even lower in the mega plate office summer because the presence rate was 25%. The perimeter of the mega plate office had high illuminance both during winter and summer due to daylight from a large opening on the east side.

　Most workers responded more satisfaction to the temperature, indoor air quality, and space environment in the mega plate office winter than in the previous office. In addition, most workers in the mega plate office summer responded more satisfaction to the indoor environment. In the mega plate office winter, the number of workers who selected the indoor environment as the reason for seat selection decreased; further, several workers selected a seat based on communication and work content. Further, in the mega plate office summer, the number of workers who selected communication as the reason for seat selection increased because they came to the office when face-to-face communication was necessary. In the mega plate office winter, the meeting space was expanded, making communication easy. Moreover, the addition of a refreshment space facilitated refreshing breaks. In the mega plate office summer, the number of office workers who selected communication as the reason for seat selection increased, making communication easy.

　In the mega plate office winter, workers with high work engagement could fully exercise their ability to select their work environment because of the high selectivity of the work environment; further, they could concentrate on their work and refresh themselves easily. The workers with higher work engagement were more likely to engage in creative activities because the presence rate decreased in the mega plate office summer, further increasing the selectivity of the work environment.

◆　Backgrounds and Policy

　As ESG investment spreads worldwide, buildings that contribute to human health are drawing increasing attention. From the perspective of securing excellent human resources, the need for health management in companies is increasing. Furthermore, especially in Japan, the workplace productivity of workers must be improved due to the declining working population and aging.

　For these reasons, the implementation of "Wellness Office", which enable workers to work healthily and intellectually, should be expanded. Therefore, in this study, we quantitatively clarify the influence of the office environment on the workers’ workplace productivity and health (hereinafter called "Wellness") as supportive information in order to spread Wellness Office.

◆　Internet Questionnaire Survey

　Prior to the survey, we hypothesized how the office environment would affect workers’ wellness. We considered that there are "direct effects" and "indirect effects (via work style)" in the way that the office environment affects the Wellness.

　Note that workplace productivity is defined by four indicators of "Work efficiency", "Knowledge creation", "Employee motivation", and "Securing human resources". Moreover, health is also defined by four indicators of "Subjective symptom"," Work functioning impairment", "Sickness or injury presence", and "Self-rated health".

　The survey was conducted targeting people working in an office. We obtained 1,152 valid samples.

◆　Structural Understanding of How the Environment Surrounding Workers Affects the Wellness

　Structural equation modeling was conducted using the results of the internet questionnaire to create a model based on the hypothesis. The goodness of fit of the completed model was good (CFI=0.9912, RMSEA=0.0195), indicating that the hypothesis cannot be rejected. Furthermore, by drawing the path diagram of the completed model, we systematically understood the effect of the office environment on the Wellness. The following points were mainly clarified from the path diagram.

✓　By improving the office environment, not only can workers work comfortably, but the burden of work can also be reduced.

✓　The more active communication within the company, the better the workplace productivity and health of workers.

✓　It has been shown that reducing the burden of work improves subjective symptoms and leads to securing human resources. On the other hand, the heavier the burden of work, the greater the motivation of employees.

◆　Total Effect of Office Environment on Wellness

　Regarding the path diagram of the completed model, we calculated the "total effect", which is the sum of "direct effects" and "indirect effects", of the office environment on the Wellness. The following points were mainly clarified from the "total effect ".

✓　Space design (ex. interior, rest space, conference room) has a great impact on workers’ workplace productivity.

✓　The Heat / Air / Light environment are effective for workers’ workplace productivity as well as the health.

　In summary, it became clear that the office environment induces various behaviors in the office and greatly contributes to improving the Wellness.