The Impact of Design Interventions on Occupant Satisfaction: A Workplace Pre-and Post-Occupancy Evaluation Analysis

Understanding how occupants perceive the built environment is a growing interest in sustainability research. This article looks into how design interventions in a workplace renovation project impact occupants’ satisfaction through a pre-and post-occupancy survey. In two years (from 2016 to 2018), an interdisciplinary research team from the University of Minnesota administered online occupancy surveys at the headquarters of the Cuningham Group, a national renowned design firm in Minnesota. The surveys included 12 indoor environmental quality categories (with 26 criteria on a 7-point Likert scale) that measured how occupants perceived their existing workplace and the renovated environment. Mann–Whitney U tests and Chi-square tests were conducted for 12 indoor environmental quality categories between the pre-and post-surveys. Results showed that occupants’ satisfaction significantly increased with the design interventions in the renovated workplace. Perceived work performance and health also improved in the post-survey. Among 12 indoor environmental quality categories, occupants perceived the biggest improvements in lighting such as adjustability and quality of task lighting. Design interventions in electric lighting, especially improved ease of control, effectiveness of automatic systems, plus visual and acoustic comfort, contributed to occupants’ satisfaction. Overall, the pre-and post-occupancy evaluation survey analysis confirmed the positive impact of the renovated Cuningham Group facility. The article presents a comprehensive measure of the impact of the data-driven design interventions derived from pre-and post-occupancy evaluation surveys on occupant satisfaction.

CONCEPTUAL FRAMEWORK OF CULTURAL BACKGROUND IN THE LIT ENVIRONMENT

In environmental terms, culture represents the climatic and indoor conditions people have experienced during a significant part of their life. Consequently, people exposed to different cultures might have different expectations of the lighting environment. Knowing the lighting expectations due to cultural experiences have numerous advantages; it could help meet the occupants’ needs and preferences and provide occupant satisfaction, reducing unnecessary energy consumption in the built environment. This paper aims to summarise a systematic review to create a conceptual framework of cultural background in the lit environment, which could help understand the impact of cultural background on daylight perception and expectation. This review highlighted that cultural background in lighting environment should be evaluated considering (1) the ethnicity and/or physiological characteristics of the individual eyes, (2) the area (luminance environment) where people used to live (3) the luminance environment they were recently exposed to and (4) the socio-cultural background of individuals. Future research should further test these components together and separately to investigate which component or combination is more influential on daylight perception.

Are automated daylight control systems working as they should?

<p>Lighting in office buildings can account for approximately 30% of electrical use. This provides an opportunity for energy efficient technologies to be implemented to reduce this load. Automated daylight control systems are part of a growing industry, based on complex electronics and careful placing of light sensors. In an economy that is accepting the need for energy reduction due to the realisation of limited fossil fuels, it is important to maintain and enhance energy efficient systems. Research highlighted that previous studies would either use a physical measuring approach or an occupant survey to understand how well automated daylight control systems are working, but never both. This thesis combined both of these approaches to quantify how much energy automated daylight control systems are saving while ensuring that occupant satisfaction and comfort is maintained. Four office buildings within Wellington city were therefore analysed to investigate the average energy saving from automated daylight control systems. Energy savings reported from other research studies ranged from 15% to 80%, with an average of 49%. The savings from the four buildings researched in this thesis average 20% savings. The surveys further indicated that all occupants within each of the buildings were satisfied with both natural and artificial lighting in their working environment. Glare was however highlighted as an issue.</p>

Are automated daylight control systems working as they should?

<p>Lighting in office buildings can account for approximately 30% of electrical use. This provides an opportunity for energy efficient technologies to be implemented to reduce this load. Automated daylight control systems are part of a growing industry, based on complex electronics and careful placing of light sensors. In an economy that is accepting the need for energy reduction due to the realisation of limited fossil fuels, it is important to maintain and enhance energy efficient systems. Research highlighted that previous studies would either use a physical measuring approach or an occupant survey to understand how well automated daylight control systems are working, but never both. This thesis combined both of these approaches to quantify how much energy automated daylight control systems are saving while ensuring that occupant satisfaction and comfort is maintained. Four office buildings within Wellington city were therefore analysed to investigate the average energy saving from automated daylight control systems. Energy savings reported from other research studies ranged from 15% to 80%, with an average of 49%. The savings from the four buildings researched in this thesis average 20% savings. The surveys further indicated that all occupants within each of the buildings were satisfied with both natural and artificial lighting in their working environment. Glare was however highlighted as an issue.</p>

Integrated Household Appliance Scheduling With Modeling of Occupant Satisfaction and Appliance Heat Gain

With the prevalence of building automation and Internet-of-Things technologies, home energy management has become an active area in recent years. This paper proposes an integrated, multi-objective Home Energy Management System (HEMS), which optimally schedules controllable electric household appliances to balance three objectives: 1) home energy cost; 2) the occupant’s use satisfaction of controllable appliances; and 3) the occupant’s thermal comfort. In particular, the HEMS models the coupling operational relationship between the non-thermostatically controlled appliances and the air conditioner by investigating the impact of heat gains released by the appliances on the indoor temperature. An advanced multi-objective optimizer is applied to solve the home energy management model. Simulations are conducted to validate the proposed method.