Toward better office design standards

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Publisher’s version / Version de l'éditeur:

Lighting Magazine, 3, 3, pp. 23-24, 62, 1989-03

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Toward better office design standards

Tiller, D. K.

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Toward Better Office Design

Standards

by D.K. Tiller

Reprinted from

Lighting Magazine

Vol. 3, No. 3,

1989

pp. 23-24, 62

(IRC Paper No.

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Toward better office design standards

The National Research Council

is

conducting experiments in

a new Subjective Reactions Laboratory facility aimed at a

deeper understanding of the psychological aspects of

lighting in the office environment.

-

_{by Dale K. Tiller, D.Phil.}

Institute for Research in Construction National Research Council of Canada

4,

Ottawa

esides banishing the night, and helping people see more effectively in order to perform theirtasks, Iightingcan also be used to satisfy subtle psychological and aes- thetic ends in addition to its more utili- tarian functions.

Indeed, the psychological impressions cued by different Iightingdesigns

might be useful in the workplace, to lower absenteeism and perhaps even to increase productivity. However, when compared with our understanding of how lighting affects task visibil- ity, our knowledge of how lit environments cue particular subjective impressions in-people remains poor.

John Flynn, who worked at Penn

Table 1

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Lighting Reinforcement of Subjective Effects

Subjective Impression Reinforcing Lighting Modes

lmpression of Visual Clarity Bright, uniform lighting mode Some peripheral emphasis, such as with high reflectance walls or wall lighting

lmpression of Spaciousness Uniform, peripheral (wall) lighting Brightness is a reinforcing factor, but not a decisive one

Impression of Relaxation , Non-uniform lighting mode

Peripheral (wall) emphasis, rather than overhead lighting

lmpressions of Privacy or

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Non-uniform lighting mode Intimacy

Tendency toward low light intensities in the immediate locale of the user, with higher brightnesses remote from the user

Peripheral (wall) emphasis is a reinforcing factor, but not a decisive one

lmpressions of Pleasantness Non-uniform lighting mode and Preference

Peripheral (wall) emphasis

From Flynn, J.E. A study of subjective responses to low energy and non-uniform lighting systems. Lighting Design and Application, Feb., 1977, p.8.

Reprinted from LIGHTING Magazine, JUNE 1989

State University during the 1970s, was one of the first to provide insight into the objective assessment of the more qualitative, subjective and ethereal aspects of lighting. Despite the fact that Flynn only ever published seven research papers, and the last of these ap- peared nearly a decade ago, his work has had acontinuing influenceon the lighting research and design commu- nities alike.

Flynn's research revolutionized our understanding of the psychological effects of lighting, and influenced a gen- eration of lighting designers who re- ceived their training at Penn State. Flynn's findings led to a lightingdesign "cookbook", depicted in Table 1, that tells the designer how to achieve specific subjective impressions with different design strategies.

Notwithstanding its influence, Flynn's work was limited in at least one important way. It does not tell designers what measurable aspects of the luminous environment must be varied to achieve specific subjective impressions.

Although Table 1 seems to provide this guidance, a closer reading of Flynn's work shows that no extensive measures of the luminous environments used in his studies were ever taken. So, for example, there is no in- dependent physical definition of what constitutes overhead, or bright lighting, other than a person's judgment that it was so.

This is important because it means that designers still have to rely on their intuition about what quantitative aspects of light must be varied to achieve the qualitative effects described by Flynn. Only when the relationships between specific subjective effects and variations in physical qualities have been established, can variations in o b jectively measured qualities be used to

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predict subjective effects.

Unfortunately, such predictive power i s not currently available to lighting designers.

Flynn cannot be criticized too se- verely for this omission, however, as it is only in the past year that practical measurement tools have become available for quickly and accurately charac- terizing luminous environments. Using conventional photometry, it could take months to specify the luminous char- acteristics of a space or scene.

Recent developments in computer- based luminance and image analysis photometry now make possible the rapid specification of luminous environments. The influence of single and combined photometric measures on subjective impressions can be explored and modeled as never before.

With Flynn's untimely death in 1979, interest in the psychological aspects of lightingwaned, and the initial promise in hiswork has remained largely unful- filled. Nevertheless, there has been a reawakening of interest in issues raised by Flynn's work in the North American research community.

The Institute for Research in Con- struction, National Research Council of Canada (IRUNRC), has recently em- barked on a research program to build on Flynn's work. Studies are being planned that will help develop an understanding of relationships that exist between measured physical aspects of the luminous environment, and occupant reactions to these variables, using state-of-the-art measurement tools as described above, in a new laboratory facility.

This new laboratory facility was de- signed by a steering committee con- sisting of prominent designers, archi- tects, engineers and academics. The steering committee was structured to ensure that important areas for interi- or design were addressed in facility construction and the subsequent research program. Financial support for facility construction was provided jointly by Public Works Canada and I RUN RC.

The research facility

The facility itself consists of four rooms furnished to represent "typical" North American middle management office stock. A wide range of lighting hardware (e.g., lamps, luminaires, baf- fles, lenses and diffusers) is available,

providing great flexibility to explore the relationships between different lighting design strategies and occupant performance, perception, and subjective reactions.

Each of the four offices in the facility is nominally 12 ft. X 15 ft., with an 8-ft. ceiling. A concealed spline noncham- phered ceiling was installed throughout the four rooms and corridor, to remove any obvious clues about room size that experimental subjects might obtain by counting ceiling tiles.

Achromatic shades of gray were used on the interior finishes and furnishings throughout, to prevent any changes in surface luminances occurring as a function of light source colour.

Each of the four rooms has a different lighting scheme. One room has high intensity overhead lighting; one has combination overhead and peripheral lighting from a wall washing luminaire; one room is lit using low intensity overhead lighting; and one is lit only by low intensity peripheral lighting. According to Flynn, each of these different design strategies should lead to distinct occupant impressions.

Experiments are being planned to investigate the effects of the spatial distribution and intensity of light on occupant impressions of room spaciousness and brightness. Preliminary findings indicate, for example, a room lit using wall lighting will be judged as brighter and more pleasant than another providing the same task illu- minance from overhead.

Although tentative, this finding sug- gests that it may be possible to achieve impressions of equivalent or greater room brightness with reduced lighting power density, thus identifying a source of potential energy savings. More extensive work along these lines will deepen our understanding of the psychological aspects of lighting, and this improved understanding will form a knowledge base of rational principles for lighting designers.

In subsequent years, the scope of research in the facility will be broadened to include investigations into the subjective effects of still other indoor environment variables that can influence occupant satisfaction, comfort, health and productivity, including such fac- tors as ventilation, air quality, thermal comfort and acoustics.

Ultimately, this workwill lead tothe development of practical evaluation

tools for assessing the quality of actu- al indoor office environments. These practical assessment tools might then be employed in the facility itself, to provide industry with a standard office testing environment and protocol. Oc- cupant reactions to proposed indoor environment design changes could then be examined before full scale im- plementation, to determine if these

new ideas, products, or processes suc-

.

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cessfully meet their specified design

goals.

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