Occupant satisfaction in LEED and non-LEED certified buildings

Occupant satisfaction with indoor environmental quality (IEQ) in office buildings has been positively correlated to self-estimated job performance and, potentially, to overall company productivity. LEED is a voluntary, consensus-based, market-driven program that provides third-party certification of green buildings, contributing to promote sustainability into the mainstream of building design and construction. From the literature, however, it is unclear the extent to which LEED certification also improves occupant satisfaction with IEQ. The aim of this paper is to study if LEED certified buildings lead to a higher, equal or lower satisfaction with indoor environmental quality than non-LEED rated buildings. Occupant satisfaction has been evaluated on a subset of the Center for the Built Environment Occupant Indoor Environmental Quality Survey database featuring 144 buildings (65 LEED certified) and 21,477 individual occupant responses (10,129 in LEED buildings). Differently from previous studies of the CBE database, the results show that occupants of LEED certified buildings have equal satisfaction with the building overall and with the workspace than occupants of non-LEED rated buildings. The difference in mean satisfaction scores between LEED and non-LEED buildings for other 15 IEQ parameters investigated is always lower than 6% with a negligible effect size. Therefore, it can be concluded that there is not a significant influence of LEED certification on occupant satisfaction with indoor environmental quality, although the analysis of mean votes of satisfaction reveals that occupants of LEED buildings tend to be slightly more satisfied with air quality, and slightly more dissatisfied with amount of light

Influence of factors unrelated to environmental quality on occupant satisfaction in LEED and non-LEED certified buildings

Occupant satisfaction in office buildings has been correlated to the indoor environmental quality of workspaces, but can also be influenced by factors distinct from conventional IEQ parameters such as building features, personal characteristics, and work-related variables. A previous study by the authors analyzed occupant satisfaction in LEED and non-LEED certified buildings on a subset of the Center for the Built Environment survey database featuring 21,477 responses from 144 buildings (65 LEED-rated). The data suggested that, when evaluated comprehensively, there is not a practically significant influence of LEED certification on occupant satisfaction. The aim of this paper is to investigate the impact on users’ satisfaction in LEED and non-LEED certified buildings of factors unrelated to environmental quality, including consideration of office type, spatial layout, distance from window, building size, gender, age, type of work, time at workspace, and weekly working hours. The results show that such factors statistically significantly influence the difference in occupant satisfaction in LEED and non-LEED certified buildings, but the effect size of such variations is, for most, practically negligible. However, tendencies were found showing that LEED-rated buildings may be more effective in providing higher satisfaction in open spaces rather than in enclosed offices, in small rather than in large buildings, and to occupants having spent less than one year at their workspace rather than to users that have occupied their workplace for longer. The findings suggest that the positive value of LEED certification from the point of view of occupant satisfaction may tend to decrease with time

Leveraging ubiquitous computing as a platform for collecting real-time occupant feedback in buildings

Building occupants represent a rich source of information for evaluating environmental design practices and building operations.  This paper presents a scalable diagnostic technology for collecting real-time Indoor Environmental Quality (IEQ) feedback from building occupants: an interactive desktop polling station. The device demonstrates the potential of ubiquitous computing, a model of human-computer interaction in which information processing is integrated into everyday objects, to engage occupants in providing IEQ feedback in real work environments.  Example data from a field study of a high-performance office building are presented demonstrating the applicability of multiple devices to acquire detailed feedback over daily and seasonal variations in climatic conditions.  Sample results show how polling station data can help identify the frequency and magnitude of discomfort with the spatial and temporal granularity needed to assess, validate, and improve the performance of environmentally responsive building technologies, controls, and design strategies. Analysis of repeated-measures subjective assessments paired with concurrent physical measurements is performed to demonstrate how existing standards and assumptions for occupant comfort could be evaluated and refined using detailed occupant feedback from buildings in use.  Results are discussed regarding implications for improving decision-making for the design, certification, and operation of environmentally responsive buildings

Occupant productivity and office indoor environment quality : a review of the literature

The purpose of this paper is to review the existing literature to draw an understanding of the relationship between indoor environmental quality and occupant productivity in an office environment. The study reviews over 300 papers from 67 journals, conference articles and books focusing on indoor environment, occupant comfort, productivity and green buildings. It limits its focus to the physical aspects of an office environment. The literature outlines eight Indoor Environmental Quality (IEQ) factors that influence occupant productivity in an office environment. It also discusses different physical parameters under each of the IEQ factors. It proposes a conceptual model of different factors affecting occupant productivity. The study also presents a review of the data collection methods utilised by the research studies that aim to investigate the relationship between IEQ and occupant productivity. The study presents a comprehensive discussion and analysis of different IEQ factors that affect occupant productivity. The paper provides a concise starting point for future researchers interested in the area of indoor environmental quality

The human factors of sustainable building design: post occupancy evaluation of the Philip Merrill Environmental Center

It is widely believed that sustainable building design strategies create improved indoor environmental quality and should, thus, be associated with improved occupant comfort, satisfaction, health, and work performance relative to buildings designed around standard practices. Yet, this belief remains a hypothesis with little empirical support.The study described in this report represents a beginning step in understanding the human factors impacts of sustainable design practices. The report summarizes the findings from a study of the Philip Merrill Environmental Center building in Annapolis, Maryland. The building, which houses the Chesapeake Bay Foundation, was the first LEED Platinum building in the United States.The Occupant Indoor Environmental Quality Survey, a widely used building evaluation instrument developed by the Center for the Built Environment at the University of California at Berkeley, was implemented in November 2004, almost four years after the Foundation moved into the new building. In addition to the survey, a series of interviews and discussion groups were held with staff one year after the move into the new building. This report includes a detailed summary of the survey findings with additional clarification of occupant responses gathered from the interviews and discussion groups

A web-based POE tool for measuring indoor environmental quality

The Post Occupancy Evaluation (POE) process provides necessary feedback to the building industry, fostering the improvement of existing facilities as well as contributing to knowledge that improves the planning, design, construction and operation of future facilities. Surveys of building users are a key component of successful POEs. The Center for the Built Environment (CBE) at the University of California, Berkeley, has developed a Web-based survey that can quickly and inexpensively collect occupant perceptions about the environmental quality of the workplace, as well as opinions of other audiences involved in the design, construction and maintenance of the facility. The growing database of standardized survey responses can be analyzed for trends in building technologies and design techniques. CBE has developed and continues to develop tools that facilitate the analysis and display of the data collected by the survey. Case studies demonstrate that the survey has been effective in helping pinpoint problems

Demand Shifting with Thermal Mass in Light and Heavy Mass Commercial Buildings

The potential for utilizing building thermal mass for load shifting and peak demand reduction has been demonstrated in a number of simulation, laboratory, and field studies. This project studied the potential of pre-cooling and demand limiting in a heavy mass and a light mass building in the Bay Area of California. The conclusion of the work to date is that pre-cooling has the potential to improve the demand responsiveness of commercial buildings while maintaining acceptable comfort conditions. Results indicate that pre-cooling increases the depth (kW) and duration (kWh) of the shed capacity of a given building, all other factors being equal. Due to the time necessary for pre-cooling, it is only applicable to day-ahead demand response programs. Pre-cooling can be very effective if the building mass is relatively heavy. The effectiveness of night pre-cooling under hot weather conditions has not been tested. Further work is required to quantify and demonstrate the effectiveness of pre-cooling in different climates. Research is also needed to develop screening tools that can be used to select suitable buildings and customers, identify the most appropriate pre-cooling strategies, and estimate the benefits to the customer and the utility

Listening to the occupants: a Web-based indoor environmental Quality Survey

Building occupants are a rich source of information about indoor environmental quality and its effect on comfort and productivity. The Center for the Built Environment has developed a Web-based survey and accompanying online reporting tools to quickly and inexpensively gather, process and present this information. The core questions assess occupant satisfaction with the following IEQ areas: office layout, office furnishings, thermal comfort, indoor air quality, lighting, acoustics, and building cleanliness and maintenance. The survey can be used to assess the performance of a building, identify areas needing improvement, and provide useful feedback to designers and operators about specific aspects of building design features and operating strategies. The survey has been extensively tested and refined and has been conducted in more than 70 buildings, creating a rapidly growing database of standardized survey data that is used for benchmarking. We present three case studies that demonstrate different applications of the survey: a pre/post analysis of occupants moving to a new building, a survey used in conjunction with physical measurements to determine how environmental factors a#ect occupants' perceived comfort and productivity levels, and a benchmarking example of using the survey to establish how new buildings are meeting a client's design objectives

A web-based POE tool for measuring indoor environmental quality

The Post Occupancy Evaluation (POE) process provides necessary feedback to the building industry, fostering the improvement of existing facilities as well as contributing to knowledge that improves the planning, design, construction and operation of future facilities. Surveys of building users are a key component of successful POEs. The Center for the Built Environment (CBE) at the University of California, Berkeley, has developed a Web-based survey that can quickly and inexpensively collect occupant perceptions about the environmental quality of the workplace, as well as opinions of other audiences involved in the design, construction and maintenance of the facility. The growing database of standardized survey responses can be analyzed for trends in building technologies and design techniques. CBE has developed and continues to develop tools that facilitate the analysis and display of the data collected by the survey. Case studies demonstrate that the survey has been effective in helping pinpoint problems