Are Naturally Ventilated LEED Buildings Healthier?

Green building rating systems such as Leadership in Energy and Environmental Design (LEED) employ a variety of design solutions to reduce energy and minimize environmental damage. These solutions, such as the use of passive ventilation, do not necessarily lead to improvements in occupant health.

• Passive ventilation strategies employed to reduce energy can lead to uneven airflow distribution and low air exchange rates. This can potentially lead to localized increases in building related emissions such as the off-gassing of volatile organic compounds.
• Methods to reduce volatile organic compounds (VOC) and airborne particulate entrainment, such as the elimination of carpets and furnishings, can result in increased acoustical noise and reverberation time. Passive ventilation apertures that allow the free movement of air between rooms and corridors can lead to uncontrolled noise transmission.

Prescriptive measures embedded in the LEED rating system and the structure of the rating method (selective point scoring) do not always ensure high Indoor Air Quality (IAQ).

• LEED recognizes the need to encourage low emission materials and provides support for alternative material selection. However, periodic measures of performance provide meaningful information for building managers and occupants.
• LEED buildings may qualify for a high level of certification with multiple points for energy efficiency but the minimum number of points for IAQ. This means that a high certification level such as Platinum or Gold is not necessarily synonymous with high quality indoor environments.

There exists a research gap between how buildings are designed and how buildings perform in terms of human health. The knowledge gap can be remediated by:

• Incorporating lessons learned from Sick Building Syndrome (SBS) studies which can be used to inform both future exposure studies and mitigation strategies for green buildings with ventilation problems.
• Acknowledging the need to move away from prescriptive design processes employed by LEED and towards performance-based measurements enforced by regionally determined benchmark standards.