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Daylight and Seating Preference in Open-Plan Spaces

Zeynep Keskin

PhD student

Lighting Research Group

School of Architecture

University of Sheffield

Supervisor: Prof. Steve Fotios

Daylight and Behaviour

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BACKGROUND

Past research suggests that daylight affects seating location.

 However, whilst they have reported a tendency to sit near windows, they did not

provide a quantified measure of seat use and daylight.

STUDY METHOD OUTCOME: DID DAYLIGHT AFFECT

OCCUPANT BEHAVIOUR?

Wang &

Boubekri

(2009)

 Occupants’ seat choice in a south-facing

student union lounge

 Observation period: 1pm-4pm on three

consecutive afternoons during mid-April

 YES: Participants preferred seats in

sunlight

 Away from sunny area, they preferred

seats in more open spaces

Christoffersen

et al. (2000)

 A survey was carried out in 20 Danish

office buildings during the spring and

autumn of 1997

 YES: Participants preferred seats in the

window zone

 The degree of satisfaction increased

with increasing daylight factor

Organ & Jantti

(1997)

 Occupants’ seat choice in a daylit library

building

 Observation period: 10am,1pm,3.30pm

from 20 June to 30 October 1996

 YES: It was observed that the most

popular areas were quiet, well lit and

adjacent to windows.

 This project is investigating a link between daylight quantity and seating preference.

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MEASURES OF DAYLIGHT

We can measure the

illuminance (Eh

) from

daylight at a point.

Daylight illuminance (Eh

) varies as

outside illuminance (Eout) varies with

time of day, year and cloud cover.

Therefore, illuminance is not a

suitable measure.

Daylight Factor (DF)

A measure of internal daylight

versus external daylight.

DF = Eh

/Eout (%)

Daylight Autonomy (DA)

The percentage of working year

when Eh

is above a minimum

threshold (typically 300 lux), and

thus provides sufficient light for

working.

Useful Daylight Illuminance (UDI)

The percentage of working year when

Eh

is above a minimum threshold

(typically 100 lux) but below an upper

limit of 3000 lux – the risk of glare

when blinds may be closed.

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RESEARCH PROJECT

Research question:

 Does a significant relationship exist between occupant's seating preference

and daylight availability?

 Can this be predicted with current daylight performance metrics such as

daylight factor, useful daylight illuminance or daylight autonomy?