Literature Review on Daylighting & Office Building Design 2

Daylight in Office Design


Incorporating natural light into an office space creates an opportunity to improve the environmental performance of the project, while promoting individual well-being and enabling capital building investments to provide better economic returns.
The most basic goals in office space design are to create a place where work can be accomplished and communication can occur. Today, light is instrumental in creating that productive environment, because 90 percent of the communication in the workplace occurs visually. From reading and writing email messages to seeing a co-worker’s body language and facial expressions, people use their eyes to interpret the world around them, and their eyes require light.
The same light that is the medium for visual communication also impacts the mood, health, and behavior of the employees it touches. Both natural and electric light can illuminate a space, but they do not impact people equally. Studies have corroborated a long-held belief that there is a strong correlation between positive mood and daylight exposure. Recent studies also imply that incorporating outdoor views into the office will positively effect employee motivation, satisfaction, productivity, and comfort, which can manifest in improved employee retention and workforce output.

Natural Light in an Office Space and Building Performance (Financial Efficiency)

The price of electricity used during peak demand times is higher than the price of electricity used when the overall demand wanes. Effectively using the daylight available during those business hours not only reduces the total electricity demanded by lighting and HVAC systems, but also reduces peak demand, minimizing the use of the most expensive electricity. Saving one kilowatt-hour (kWh) of energy during daylight hours saves a building more money than saving that same kWh at midnight.


Lighting Quality and Standard

There are several standards used for electric lighting. In Malaysia, the Malaysian Standard 1525:2007 has outlined illuminance levels recommendations for various tasks and applications as shown in Table 2.2. The recommended daylight factor (DF) for an effective daylight-lit office space is 1.5%. This standard should be employed as benchmark in lighting study in Malaysia. However, other criteria such as illuminance uniformity, luminance value, luminance ratio, etc. are not mentioned.

Table 2.2 Recommended average illuminance levels (MS 1525:2007)

Dubois (2001b) had studied various lighting quality standards from different sources such as IES and CIE. A combination of these standards was used for daylight analysis as shown in Table 2.3. Some of these recommendations were adapted from electric lighting standards. Therefore, daylight may give better tolerances. This study was carried out under temperate climate. Thus, the recommended DF is considerably high for tropical climate in Malaysia.

Table 2.3 Lighting performance indicator (Dubois, 2001b)

Daylight utilisation is an effective strategy for energy saving as well as visual comfort. From the above mentioned standards, it shows that many criteria should be taken consideration in order to have daylight utilisation and visual comfort. However, the current standards are adapted from electric lighting. Hence, more research is needed for daylight performance.