Re-evaluation of a LEED Platinum Building: Occupant experiences of health and comfort

1.1 Green Building Certification

In 2000, the United States Green Building Council (USGBC) developed the LEED certification program with the intent of promoting principles of sustainable development [1]. Since that time, LEED has become the industry standard for high-performance green buildings [1]. The current rating system, LEED v4, contains five rating systems for varied project types and reflects five main areas of sustainability: sustainable site design, water quality and conservation, energy and environment, indoor environmental quality (IEQ), and materials and resources [1]. Projects are certified based on the number of points achieved: certified 40–49 points; silver 50–59 points; gold 60–79 points; and platinum 80+ points [1]. One credit can be earned for a comprehensive ergonomics strategy, which is included in the additional “innovation” category [10].

In November 2012, a document containing recertification guidance under Existing Buildings: Operation & Maintenance (EB: O&M) was released, and it was updated in October 2013 [10]. This was considered to be the first step by the USGBC in establishing a clear recertification program to ensure that buildings are performing as intended. Projects initially certified under any version of LEED for existing buildings must recertify at least once every five years to maintain O&M certification. This is an important requirement as it promotes the ongoing maintenance of high performance operations through documenting set “performance requirements” for credit compliance. A sample performance requirement under IEQ: Occupant Comfort- Occupant Survey is “Action: conduct occupant comfort survey at least once every 2 years” (LEED for Existing Buildings: Operations & Maintenance Recertification Guidance document). The recertification process is still unfolding and is a very important aspect of LEED to meet the full intent of sustainable development. It is not enough for buildings to achieve LEED certification- they must continue to be held to standards to ensure they are performing to green standards as designed.

It is of importance to note a new certification system, the WELL Building Standard, which evaluates buildings in regards to human wellness within the built environment [11]. The certification system works in alignment with LEED and other global programs and has ongoing recertification requirements, and it incorporates an ergonomics requirement [11]. There are 7 rating categories, with the “comfort” category directly addressing ergonomics. This is different from the LEED rating system in that it is an essential part of the rating system in the WELL Building Standard versus an option within LEED [10, 11].

1.2 Green Buildings and occupants

The USGBC states that “LEED certified buildings save money and resources and have a positive impact on the health of occupants, while promoting renewable, clean energy” [1]. However, research has yet to demonstrate that LEED buildings automatically result in improved occupant health. In two longitudinal studies, Singh et al. [12] found that the mean numbers of depression, stress, asthma and allergies were reduced after occupants moved from conventional to green buildings. Perceptions of health and wellbeing improved as did productivity and absenteeism [12]. Similarly, Thatcher and Milner [13] suggest, through the results of their longitudinal study, that green buildings may positively impact wellbeing and productivity of occupants. There have been other studies pointing to the positive benefits of green buildings, including lower negative health symptom prevalence in LEED buildings [8] and improved perceptions of stress, health and productivity in green versus conventional buildings [3].

While there have been positive findings, there have also been persistent issues identified in green buildings that can negatively impact occupants. Newsham et al. [7] found that while green buildings generally outperformed conventional buildings in regards to IEQ from the occupants’ perspective, there can still be issues with unsatisfactory acoustics and indoor air quality. Other studies also have pointed to dissatisfaction in green buildings with lighting [3, 15], acoustics [3, 16], thermal comfort [8, 9], and air quality [3, 17]. In short, it is not a given fact that the green features of green buildings will inherently benefit the occupants by creating a more comfortable environment. It is important to continue to investigate occupant experiences to better understand the relationship between green buildings and human health and performance over time. With the current move towards a recertification process in the LEED system, it is imperative that buildings are not just studied once to gain a snapshot, but rather are continually evaluated. The current study reexamines a LEED platinum building that was studied three years prior to see what has shifted over time from the perspective of the occupants.

Our previous study of this building showed a number of issues with the indoor environmental conditions and with the ergonomic design of the office workspaces [3]. It is possible that these findings arose because occupants were relatively new to the building at the time of the study. The current survey will assess how occupants are responding to conditions in this building after being in this space for 3 years. Our hypothesis is that occupants will rate their experiences more positively in this survey than in the previous one because they will have had time to adjust to beneficial “green” design features of thebuilding.

2.1 Research site and sample

A LEED Platinum building located on the academic campus of Ithaca College, New York State, USA was selected for this study. The Peggy Ryan Williams Center (PRWC) was previously studied by Hedge and Dorsey [3] and was found to have some occupant concerns related to indoor environmental quality. PRWC is a 5,388 m² (58,000.ft²) building that opened in the fall of 2009 and was certified platinum under LEED v.2.2. Some of the green features of the building include: extensive use of daylighting, natural convection ventilation, a ground source geothermal system, use of renewable energy sources, vegetated roofing, lighting and mechanical ventilation sensor systems, varied shading devices on the glass curtain wall, rainwater collection, low-e coated glass, use of porous pavement and native vegetation, and the use of local, recycled, low-toxicity materials whenever possible [18]. The full details of the LEED credits are available online along with the scorecard for this building (http://www.usgbc.org/projects/peggy-ryan-williams-center).

There are approximately 120 employees that have primary offices in this building, and the majority of tasks are computer and paper based. Sample departments housed in this building include the registrar, human resources, and admissions. Office spaces in PRWC include perimeter private offices, cubicle offices and office suites, as well as interior cubicle offices with partial height partition walls. The north façade of the building is entirely made of glass and faces towards the lake.

2.2 Survey and procedure

Ithaca College employees, ages 18 and older, with an office/workstation in the Peggy Ryan Williams Center (PRWC) were eligible to participate in this study. This included part time and full time faculty and staff, however student workers were not eligible. Participants were asked to complete a 10–15 minute anonymous online survey investigating their experiences of their work environment within PRWC and how this work environment affects health, satisfaction and productivity.

The researchers announced the survey through the online campus announcement system, with an initial posting and a follow up reminder posting 2 weeks later. The researchers compiled the email addresses of eligible employees by looking up each department’s employee listings on the college’s website. The primary investigator then contacted eligible employees directly via email to inform them of the study and provided them with a link to the survey. The study was approved by the All College Human Subjects Review Board on November 25, 2014.

2.3 Survey

The self- made survey (S2) used in this study was based off the post occupancy evaluation survey (S1) used in the prior study [3], with additional questions asking about workstation layout and control over workstation factors such as air temperature and lighting. This replication of questions allowed comparability between the two surveys. The survey was comprised of 64 items that included:

Demographic information (age in ranges, gender, length of occupancy).

2.4 Data analysis

All survey data was analyzed using multivariate statistical analysis software (SPSS v22). Comparisons between survey responses for the current survey (S2) and a previous survey conducted 3 years earlier (S1) were made using Chi-Square tests. The effects of control on ratings were tested using independent t-tests. Descriptive statistics were used to summarize demographic variables. No individual identifying information was collected so it was not possible to match respondents across surveys.

3.1 Respondent characteristics

Complete responses were received from 62 occupants of PRWC (approximately 55% response rate), and this sample is referred to as Survey 2 (S2). Of these respondents, 24 reported having participated in the 2011 study, which will be referred to as Survey 1 (S1). The actual S1 had 35 respondents total [3].

The survey results were analyzed to compare the responses of those who said they had or had not participated in S1 and there were no statistically significant differences in responses and consequently the complete S2 data were used for the S1 and S2 comparisons.

The majority of S2 respondents were female (74.2%) with a 67.7% between the ages of 31 and 60. Respondents had worked in the building an average of 49.3 months (σ= 22.0) and at their current workstation, an average of 36.6 months (σ= 25.0).

When asked about their current experiences in PRWC almost half of respondents had workstations facing north (45.2%) and 22.6% faced south, 67.7% had private offices, 22.6% worked in a cubicle and 8.1% were in an open office. Only 9.7% reported having had an ergonomics evaluation at their current workstation, however, many respondents reported using equipment at their workstations that could be considered part of ergonomic design (see Table 1). Very few respondents reported using the common areas in the building, with 69.4% reporting never using the large outdoor deck. A majority of respondents reported that the building conditions were comfortable in the spring (72.6% responded yes), the fall (69.4%) and the summer (61.3%) but only around one third (37.1%) said that conditions were comfortable in the winter.

There were no statistically significant differences in S1 and S2 responses for the conditions reported by respondents between S2 and S1 (Fig. 1). Responses show that for S2 a majority of employees found the air temperature comfortable, the air fresh, and the air quality was good. A minority reported that the office was noisy. A large majority also said their office was bright, that daylight was good, that their furniture was comfortable and that the design of the workstation was good.

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Fig.1

Perceived office conditions for S1 and S2 at the time of each survey.

When asked about the effects of office conditions on their work performance, there were no statistically significant differences between responses from S1 and S2 (Fig. 2). For S2 a majority of respondents said their work performance actually was hindered by the air temperature and air freshness, around half said that the air quality hindered their performance, and some 40% reported that noise had this effect. Office lighting, daylight, the office furniture and the workstation design were problematic for less than 30% of the respondents.

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Fig.2

Effects of office conditions on ratings of work performance for S1 and S2.

There were no statistically significant differences between responses from S1 and S2 for the effects of office conditions on respondents’ health (Fig. 3). For S2 a majority of respondents said they felt healthier because of the office lighting, daylight, the office furniture and the workstation design. However, a majority also said that they felt less healthy because of the ambient conditions (air temperature, air freshness, air quality, noise).

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Fig.3

Effects of office conditions on ratings of health for S1 and S2.

More respondents said they were satisfied with the office air quality in S2 than in S1, otherwise there were no significant differences between the two surveys. A majority of respondents indicated satisfaction with the office lighting, daylight, and their office furniture and office workstation design.

3.6 Frequency of symptoms

Apart from reports of wrist/hand ache, significantly more respondents in S2 reported musculoskeletal and ill health symptoms than in S1 (Table 2). These differences appear to have arisen because many people in S1 reported no symptoms whereas in S2 more respondents indicated monthly symptoms.

In S2 respondents were asked about their ability to control certain conditions at work and the results are shown in Fig. 5. There was a significant effect of office type on the ability to control air temperature (p = 0.002) and 57.5% of those in private offices said that they had some or full control over their temperature, compared to 42.9% of those in cubicles and 40% of those in open offices. There was a significant effect of office type on the ability to control office lighting (p = 0.001) and 85.4% of those in private offices said that they had some or full control over their lighting, compared to 38.5% of those in cubicles and only 20% of those in open offices. There were no significant effects of office type for control of air quality, noise, the office furniture or office layout. Many of the LEED credits discussed below have requirements for providing a certain percentage of occupants with control over workstation features (USGBC, 2015a), whereas many conventional buildings typically do not offer the same controls.

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Fig.4

Effects of office conditions on satisfaction ratings for S1 and S2.

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Fig.5

Personal control of conditions reported in S2.

4.1 Limitations

There were several limitations to this study that could affect generalizability of the results. The sample size is relatively small, though it did represent a good response rate (51.7%). Both surveys, S1 and S2, were anonymous so the researchers were unable to match responses. The researchers had to rely on S2 respondents to report participation in S1, and there were a few respondents who were unsure if they had participated in S1 (their results were not included in the comparison). As with any follow up study, there are many other factors that could have impacted occupant responses over time. Given the scope of the current study, it is impossible to account for all of those factors though many were considered in the discussion section of this paper. There is a need for future research to examine occupant experiences in green buildings from a longitudinal perspective. As with conventional buildings, green buildings need to be maintained over time and ergonomics must be considered through the buildings’ lifecycle [20].

4.2 Conclusion

This study investigated current occupant experiences in a LEED platinum building, and also compared results with a prior POE of the same building. While the building is perceived positively in general, there are still some persistent issues with IEQ and negative experiences of MSDs and health. There is a clear need for LEED buildings to pursue the ergonomics credit to give specific attention to the human element of green building design. Sustainable development has three pillars that deserve equal attention, and the attention being given to the human or social pillar has been limited [2]. With rapid growth in the green building sector, the time has come to focus on the long term effects on occupants. Additionally, the shift to a recertification process for LEED buildings creates additional roles for HF/E professionals to ensure that the changing needs of occupants are met over time. The new WELL Building Standard also speaks to the importance of ergonomics in green building design and together these credits create additional opportunities for HF/E professionals to become involved in the green building certification process.