by Shane Henson — December 26, 2012—Building owners and facilities managers still unsure of whether green buildings truly deserve all the praise they have received for being more energy efficient and better for the environment and tenants’ health may be interested in reading a new report: Do Green Buildings Outperform Conventional Buildings? Indoor Environment and Energy Performance in North American Offices.
Published by the National Research Council (NRC), Canada’s premier organization for research and development, the report is a comprehensive post-occupancy investigation of the performance of “green” and “conventional” office buildings. The study included occupant surveys and physical building and energy use data collected from 24 buildings (12 green, 12 conventional) across Canada and the northern United States, says the NRC.
From analysis of their original post-occupancy field study data, and re-analysis of extant datasets on Leadership in Energy and Environmental Design (LEED) conventional building energy use, NRC concluded (among other findings) the following:
- Green buildings exhibited superior indoor environment performance compared to similar conventional buildings. Outcomes that were better in green buildings included: environmental satisfaction, satisfaction with thermal conditions, satisfaction with view to the outside, aesthetic appearance, disturbance from heating, ventilation and air conditioning noise, workplace image, night-time sleep quality, mood, physical symptoms, and reduced number of airborne particulates.
- Green building rating systems might benefit from further attention in several areas, including: consideration of a LEED credit related to acoustic performance; a greater focus on reducing airborne particulates; enhanced support for the interdisciplinary design process; development of post-occupancy evaluation protocols, and their integration into on-going certification systems.
- On average, LEED buildings exhibited lower total energy use intensity than similar conventional buildings. A specific case study from NRC’s own field study dataset confirmed the potential for substantial energy use intensity reductions through a green building renovation. However, many individual LEED buildings did not meet energy performance expectations. Further, there was little correlation between the number of LEED energy credits obtained during design and the resulting energy performance.
