Understanding the Indoor Environmental Quality (IEQ) Category in LEED BD+C Certification for Commercial Buildings
The LEED BD+C certification program for commercial buildings encourages sustainability practices. One of the categories under this program is Indoor Environmental Quality (IEQ), which awards up to 16 points to the projects. In order to achieve these points, projects need to comply with specific requirements for each credit.
The credits under the IEQ category are as follows:
- Minimum Indoor Air Quality Performance: This credit is mandatory and requires the calculation of fresh air availability in the different occupied spaces as per ASHRAE.
- Environmental Tobacco Smoke Control: This credit is mandatory and requires the establishment of no smoking zones within 25 feet perimeter of the building entrance areas.
- Enhanced Indoor Air Quality Strategies: This credit awards up to 2 points. Option 1 requires the implementation of entryway systems for reducing dirt and dust entering the building, while Option 2 requires monitoring of carbon dioxide levels in the building.
- Low-Emitting Materials: This credit awards up to 3 points for using low-emitting materials in various categories, including adhesives and sealants, paints and coatings, flooring, composite wood, and furniture.
- Construction Indoor Air Quality Management Plan: This credit awards 1 point for implementing a construction indoor air quality management plan to meet or exceed all applicable recommended control measures of the Sheet Metal and Air Conditioning National Contractors Association (SMACNA) IAQ Guidelines for Occupied Buildings under Construction, 2nd edition, 2007, ANSI/SMACNA 008–2008, Chapter 3.
- Indoor Air Quality Assessment: This credit awards up to 2 points. Option 1 requires testing of indoor air quality in all occupied spaces, while Option 2 requires testing of carbon dioxide levels in all occupied spaces.
- Thermal Comfort: This credit awards 1 point for achieving thermal comfort as per ASHRAE standard 55-100.
- Interior Lighting: This credit awards up to 2 points for implementing lighting control for 90% of occupied spaces and maintaining lighting quality in the occupied areas.
- Daylight: This credit awards up to 3 points for achieving daylight area in 55% of regularly occupied floor area.
- Quality Views: This credit awards 1 point for providing sight to the outdoors via vision glazing for 75% of all regularly occupied floor area.
- Acoustic Performance: This credit awards 1 point for adopting HVAC acoustic noise reduction strategies.
The projects need to provide evidence of compliance for each credit. The table below summarizes the documentation requirements for each credit:
Credit Documentation Requirements Examples Minimum Indoor Air Quality Performance Fresh air availability calculation Calculations of fresh air availability Environmental Tobacco Smoke Control Establishment of no smoking zones No smoking zone signage Enhanced Indoor Air Quality Strategies Implementation of entryway systems and/or carbon dioxide monitoring Records of implementation Low-Emitting Materials Use of low-emitting materials Copies of product documentation Construction Indoor Air Quality Management Plan Implementation of construction indoor air quality management plan Copy of the plan Indoor Air Quality Assessment Air testing results or carbon dioxide monitoring results Copies of test results Thermal Comfort ASHRAE compliance ASHRAE compliance report Interior Lighting Lighting control system design and maintenance records Maintenance records Daylight Daylight area calculations Calculations of daylight area Quality Views Vision glazing installation records Installation records Acoustic Performance HVAC acoustic noise reduction strategy implementation records Records of implementation
Projects located in certain regions may face constraints in achieving all the points under the IEQ category. For example, projects located in areas with high noise levels may face difficulty in achieving the Acoustic Performance credit. In such cases, alternative noise reduction strategies may be employed to achieve