Occupant Satisfaction in 3-star-certified Office Buildings

The effect of Chinese Green building three-star assessment standard on occupant’s satisfaction requires more research. This Article presents the findings from a comparative analysis of occupant’s satisfaction levels to Three-Star certified and non-certified office buildings in relation to the building overall, building performance and several indoor environment quality (IEQ) parameters in different seasons (cold zone, hot summer-cold winter zone, and hot summer-warm winter zone). In addition, comparative analysis was carried out to determine the effect of different rating tools on occupant’s satisfaction including LEED and BREEAM certified buildings.

Three-star evaluation standard of green buildings in China have been instrumental in the conservation of environment by sustainable use of natural resources and reducing pollution and therefore gaining increasing importance. The survey data from CBE (Centre for the Built Environment at the University of California, Berkeley) was used to analyze the occupant’s satisfaction in LEED certified buildings. Huizenga et al (2005) analyzed the occupant satisfaction in 16 LEED and 9 self-nominated green buildings and revealed that users in green buildings were more satisfied to a statistically significant degree with the building and workspace, indoor air quality, cleaning and maintenance and thermal comfort, other than lighting and acoustics. The research carried out by Altomonte et al (2016) on the analysis of satisfaction of with the building and workspace and several IEQ parameters in BREEAM and non-BREEAM certified buildings in the UK revealed that BREEAM certification does not have a significant and practically relevant effect on occupant satisfaction with buildings.

Online Questionnaire survey was carried out in all three climate zones: cold zone (Beijing), hot summer-cold winter zone (Shanghai and Chongqing) and hot summer-warm winter zone (Shenzhen) to evaluate the satisfaction levels of occupants of Three-star and non-three-star office buildings. Questionnaire were sent electronically to provide details of their basic information (gender, age, work), IEQ in different seasons (Temperature, Humidity, Air quality, Lighting, Acoustic), and building performance (building overall, building maintenance, building cleanliness, colors, comfort of furnishing). Statistical analysis was done to calculate the mean and media values of occupant satisfaction with the IEQ in the summer, transition season and winter. Averages of the satisfaction votes was calculated of all the occupants in the dataset, including for parameters like temperature, air freshness, air cleanliness, natural lighting, artificial lighting, acoustic environment, productivity, comfort of furnishing, colors and textures, space, visual privacy, building cleanliness, maintenance and building overall.

While the results indicate high satisfaction level for all parameters (positive mean value) amongst occupants of three-star certified buildings than occupants of non-certified building in all three climate zones, statistics show that effect of three-star certification on occupants in relation to the air freshness and cleanliness in transition season; humidity, air cleanliness, natural lighting and acoustic environment in winter, colors and textures, IEQ control, building maintenance, and building overall, was relatively small for all three climate zones. For LEED rating tool, differences in the mean values of satisfaction in relation to the building overall, building cleanliness, colors and textures, and air quality between the LEED and non-LEED buildings showed positive values. On the other hand, for BREEAM rating tool, the differences in the mean values of satisfaction level for the ten parameters between BREEAM and non-BREEAM buildings was found negative with higher satisfaction on air quality and visual privacy for non-BREEAM building than BREEAM buildings. The difference in the performance of non-certified buildings might be a possible reason for this difference. Non-certified buildings, those which do not perform well, makes the effect of the Three-star certification on the occupant’s satisfaction more significant.