Introducing BOSSA

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(CBE) in the US (Leaman and Bordass, 1999, Zagreus et al,. 2004) POEs. The overarching benefit from existing POE process is the provision of strategic ...
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Introducing BOSSA:

The Building Occupants Survey System Australia Christhina Candido1, Richard de Dear 1, Leena Thomas2, Jungsoo Kim1 and Thomas Parkinson1 1 

Indoor Environmental Quality Laboratory, Faculty of Architecture, Design and Planning, The University of Sydney

2 

School of Architecture, The University of Techonology, Sydney

Corresponding author: [email protected]

ABSTRACT Post-occupancy evaluation (POE) is a process that allows designers, developers, owners, operators and tenants to identify dysfunctional building services and design features, and highlight successful design. Several POE questionnaires have been developed in various parts of the world, but probably the two best known are Building Use Studies (BUS) in the UK, and the Center for the Built Environment (CBE) in the US. Perhaps the most significant shortcoming of these current generation of POE systems is that they are largely descriptive and are unable to specifically explain why a building’s scores look the way they do, because no objective indoor environmental quality (IEQ) instrumental measurements were recorded alongside the questionnaires. The Building Occupants Survey System Australia – BOSSA – is an IEQ assessment system for Australia’s office buildings. This paper describes the BOSSA system and its main components: BOSSA Time-Lapse POE, BOSSA Building Metrics, BOSSA Snap-Shot and BOSSA Nova (IEQ Assessment Cart). The BOSSA system provides, for the first time, a building performance evaluation process that will grow into an Australian database to be used to underpin an ongoing program of IEQ research aimed at improving occupants’ health, comfort and productivity outcomes from sustainable office buildings in Australia.

Keywords:  Post-occupancy evaluation, indoor environmental quality, office buildings, rating tools.

INTRODUCTION Post-occupancy evaluation (POE) is a process of gaining feedback about a building’s performance that allows designers, developers, owners, operators and tenants to objectively identify dysfunctional building services and design features, and highlight successful design. While there has been considerable focus on measuring and regulating the resource efficiency of buildings, less attention has been paid to the requirements of building occupants who represent final arbiters regarding functionality of built environments. The challenge, however, is to collect, analyse and correctly interpret occupants’ feedback in a systematic and useful manner. Several POE questionnaires have been developed in various parts of the world, but probably the two best known are Building Use Studies (BUS) in the UK, and Center for the Built Environment (CBE) in the US (Leaman and Bordass, 1999, Zagreus et al, 2004) POEs. The overarching benefit from existing POE process is the provision of strategic feedback in support of continuous improvement in our built environments. Traditionally, many decisions made during the programming or design stage of a building project are based on assumptions of how the client organisation functions and how people use their spaces. This modus operandi, relying more on “gut-feeling” than evidencebased design decisions, is proving insufficient in meeting the challenge of creating sustainable buildings. Shortcomings of this “gut-feeling” green design were also identified by Newsham et al. (2009). They analysed metered 42

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energy use across a sample of 100 LEED-certified commercial green buildings. Results revealed that 28–35 per cent of the green buildings actually used more energy than their conventional counterparts without green certification. The explanations for this alarming result included: (1) experimental green technologies were not well understood and didn’t perform as expected by the designers who specified them; and (2) there was a knowledge transfer barrier between the design team and end-users (Cooper, 2001, Newsham et al 2009). But perhaps the most significant shortcoming of current-generation POE systems is that they are largely descriptive, and hence are unable to specifically explain why a building’s POE scores look the way they do, because no objective IEQ instrumental measurements were recorded alongside the POE questionnaires. Furthermore, the research potential of current-generation POE benchmarking databases remains limited because scant details of building services and design features (building metrics) get recorded at the time of the POE. A recent metaanalysis of occupant surveys using the UK’s BUS survey tool for 22 “green design intent” buildings and 23 conventional office buildings in Australia discovered that many firstgeneration green buildings may be under-performing from their occupants’ perspective (Leaman et al, 2007). Similar results were found in Australia (Thomas, 2010, Deuble and de Dear, 2012). Unfortunately, BUS’s omission of building metrics (design features, building energy, HVAC system, etc.,), restricted that study to simply describing, rather than explaining, user responses across the various IEQ variables.

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Another meta-analysis conducted by Kim and de Dear (2012) using surveys from the CBE database concluded that since there are no instrumental observations of objective physical conditions to accompany the subjective POE data, it remains unknown how buildings in the CBE database were actually performing. So while their analysis demonstrated that occupants of air-conditioned, mixed-mode and naturally ventilated all had different perceptions of their buildings’ indoor environmental conditions, they cannot definitively say that this was the result of differences in actual physical conditions provided by the buildings. Therefore, more detailed information about actual performance of each building’s effectiveness or usability of personal control method in different buildings is crucial to make the result or discussions more concrete. This represents a fundamental limitation of contemporary POE techniques. A POE system with analytic capabilities would provide empirical performance data to determine if the occupants got what they expected, and if the various IEQ systems and strategies are performing as their designer expected/intended. These results should be used to both rectify any shortcomings and inform the next design brief. The Building Occupants Survey System Australia – BOSSA – is an IEQ assessment system for Australia’s office buildings. The BOSSA system, described in this paper, provides for the first time, an Australian-developed POE instrument, being a robust and accessible Australian alternative to other providers currently in use by NABERS and Green Star Performance rating tools. This project provides a standardised methodology for studying building performance from the occupants’ point of view, as well as providing feedback to building designers, owners, and operators. Results from this building performance evaluation process will grow into an Australian database that will be subsequently used to underpin an ongoing program of IEQ research specifically for Australian commercial buildings and their occupants1.

THE BOSSA SYSTEM The BOSSA system provide a unique combination of conventional POE questionnaires (BOSSA Time-Lapse), high-resolution ‘right-here-right-now’ questionnaires (BOSSA Snap-shot) with accompanying instrumental IEQ measurements (BOSSA Nova) and also collate building design and performance information (BOSSA Building Metrics), enables a much more rigorous attribution of causality to specific design features than is the case with current POE methods.

1.  BOSSA Time Lapse POE The first part of the BOSSA POE is a time-lapse web-based occupant survey has been developed as an integrated and flexible branching structure. The BOSSA Time-Lapse questionnaire runs on the IEQ Lab Comfort Chimp online platform, and questionnaire answers are logged and time-stamped by a central server. Figure 1 shows one of the pages of the BOSSA Time-Lapse POE questionnaire running on the IEQ Lab Comfort Chimp online platform.

www.bossasystem.com

Figure 1.  BOSSA Time-Lapse POE.

Core questionnaire items assess occupant satisfaction with the key IEQ topics: office lay-out, office furnishings, thermal comfort, indoor air quality, lighting, acoustics, and building cleanliness and maintenance. Apart from these traditional items, BOSSA Time-Lapse also includes questions especially designed to focus on “activity-based” fit-outs, views and the occupants’ control over their immediate indoor environment to reflect ongoing changes and priorities in contemporary workplaces. The questionnaire platform has the possibility to expand to include modules designed to accommodate specific questions about any of the IEQ components.

2.  BOSSA Building Metrics An integral and innovative part of the BOSSA Time-Lapse POE is the systematic collation of Building Metrics that is critical to the attribution of occupant (dis)satisfaction to specific building design features, fit-out or building services technology. BOSSA Building Metrics comes as an online and tablet application and comprises two modules: Base Building, and Tenancy. Figure 2 illustrates pages for (a) online and (b) tablet application. These two modules unable standardised data

1.  Examples of the powerful capabilities of databases like this for research purposes have been established in the literature but

probably the most influential one was funded by ASHRAE back in the 90s (de Dear, 1998) . As with any other tool, building occupants involvement is confidential. Any information, including results, may be shared with other people other than the researchers from this project for research only purposes. However this information is completely de-identified in such manner that will never allow building occupants to be identified. The results of the statistical data can be presented on our BOSSA research reports and published in scientific meetings and journals, but none of the research outputs related to this project will allow direct identification of the occupants or the building in which they work. As part of an ongoing research project, the University of Sydney’s IEQ Laboratory developed an online and a mobile IEQ survey platform called Comfort Chimp. Developed for desktop and touch devices using JQuery framework, it is platform independent and supports major browsers and mobile operating systems. Supported question types include drop-down selection, radio buttons, checklists, sliders, and text input. Responses are stored in an online database and displayed in real time to an online control panel. For more information: www.bossasystem.com D E C E M B E R 2 0 1 3  •  E CO L I B R I U M

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collection about: building basic information, building metrics and design (including fit-out), lighting and daylighting, HVAC and ventilation (including system and personal control) for each and every building entering the BOSSA database. This information is sourced from the building owner, tenant and/or facilities manager.

BOSSA Building Metrics provides the ideal platform to launch a program of IEQ research on diverse questions relating to occupant satisfaction with specific design features. For instance an increasing number of Australian office buildings are using chilled-beam space conditioning systems, as they represent an energy-efficient solution). Buildings with chilled beams are very likely to be included in the BOSSA Time-Lapse POE database, and we will be able to compare their overall occupant thermal comfort assessments against comfort ratings across the remainder of the database or some sub-set thereof – e.g. buildings with variable-air volume (VAV) air conditioning designs. Adding another layer of research interest to such comparisons is BOSSA’s Building Metrics (e.g. thermal comfort energy consumption per square meter floor area per annum), which allow the BOSSA research team to answer questions such as “Does spending less HVAC energy impair overall occupant satisfaction, comfort and productivity, and if so, by how much?”. As the BOSSA database grows in terms of number and diversity of buildings, there is an opportunity to select out sub-samples of buildings with a specific design feature, and then compare occupant satisfaction with that design feature against the rest of the BOSSA database (without that design feature).

3. BOSSA SNAP-SHOT AND BOSSA NOVA CART

a)

A complementary part of the BOSSA system is referred to as Snap-Shot. This optional add-on survey module is administered to building occupants with instructions to evaluate the IEQ of their workstation on a “right-here-rightnow” basis. These “snap-shot” field studies typically use a longitudinal research design applied repeatedly to small samples of building occupants. Time-and-place matching of subjective and objective IEQ assessments permits quantitative analysis of causal associations between indoor environmental qualities and the subjective evaluations of those qualities by the occupants.

www.bossasystem.com Figure 3. BOSSA Snap-Shot. b) Figure 2.  BOSSA Building Metrics: (a) Online and (b) tablet version.

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The BOSSA Snap-Shot questionnaire is accompanied by instrumental IEQ measurements in the same place at the same time as the questionnaire was being completed.

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The snap-shot questionnaire is again a web-based tool. The accompanying physical indoor climate measurements are collected by an IEQ Assessment Cart (BOSSA Nova) left in situ for the duration of the snap-shot survey (i.e. one week). The BOSSA Nova cart is depicted in Figure 4. This data acquisition system registers the main indoor microclimatic variables including air and globe temperatures, air speed, humidity, indoor air quality, acoustics and lighting.

feature minimises the recurrence of design shortcomings and accelerate the diffusion of good design strategies and practices across Australia’s commercial building sector. The BOSSA database’s analytic capabilities are unique and unrivalled by current building POE tools anywhere in the world. BOSSA’s power at the individual building level lies in its ability to identify specific design features, fit-out details or building services prompting occupant dissatisfaction and requiring remediation. The value of this capability will be profoundly amplified at BOSSA’s whole-database scale of analysis, where many buildings sharing similar specific design feature can be grouped together and their corresponding occupant IEQ ratings can be benchmarked against the remaining buildings in the BOSSA database. This innovation in the BOSSA approach elevates POE from a descriptive building diagnostic aid to a powerful building research tool.  ❚

ACKNOWLEDGEMENTS This research is supported under Australian Research Council’s Linkage Projects funding scheme (LP1102000328) and Industry Partners (Arup, Brookfield-Multiplex, The GPT Group, Investa Property Group and Stockland). This research was also supported under Australian Research Council’s Discovery Projects funding scheme (DP110105596) and NCCARF National Climate Change Adaptation Research Facility (NCCARF). The authors also acknowledge the in-kind support received from Australia’s NABERS – the National Australian Built Environment Rating System (managed by the NSW Department of Environment, Climate Change and Water) and Green Star-Performance (managed by the Green Council of Australia). Figure 4. BOSSA Nova IEQ Cart.

CONCLUSIONS Currently, these are the only two officially accredited POE instruments within the National Australian Built Environment Rating System (NABERS) for commercial buildings. The BOSSA project not only rectifies this situation, but also opens up IEQ research questions that are inaccessible to the current generation of POE systems. The combination of BOSSA’s much more detailed building metrics and instrumental IEQ measurements (snap-shot) alongside conventional POE questionnaire items (time-lapse) accelerates the acquisition of knowledge in the built environment disciplines, and at the same time, enhance the IEQ assurance processes of our built environmental professions. Extant POE systems are building diagnostics aimed at merely identifying successes and failures, but lacking the analytic capability to definitively explain critical differences between good and bad buildings. The primary innovation of BOSSA is the possibility to identify how and explain why some buildings are not performing up to expectations, while others are exemplary. BOSSA’s unique combination of a) detailed building metrics, b) conventional time-lapse POE questionnaires, and c) high-resolution snap-shot questionnaires with accompanying instrumental measurements of objective IEQ parameters, enable a much more rigorous attribution of causality to specific design features than is the case with current POE methods. This new 46

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Special thanks to Ashak Nathwani for feedback on BOSSA Building Metrics.

REFERENCES Building Use Studies, retrieved August 30 2012, http://www.usablebuildings.co.uk CBE Occupant Indoor Environmental Quality (IEQ) Survey, retrieved August 30, 2012, Cooper, I. 2001. “Post-Occupancy Evaluation – Where are you?” Building Research and Information 29 (2): 158–163. de Dear, R.J. (1998) “A global database of thermal comfort field experiments,” ASHRAE Transactions., V.104(1b), pp.1141–1152. Deuble, M. P. and R. J. de Dear. 2012. “Green occupants for green buildings: The missing link?” Building and Environment 56: 21–27. Kim, J. and R. de Dear. 2012. “Nonlinear relationships between individual IEQ factors and overall workspace satisfaction.” Building and Environment 49 (1): 33–40. Leaman, A. and B. Bordass 1999. “Assessing building performance in use 4: The Probe occupant surveys and their implications.” Building, Research & Information 29 (2): 129–143.