What Is LEED? – Indoor Environmental Quality

October 21, 2014

This is the seventh post in a series on the LEED green building rating system. The first post provided an Introduction to LEED, the second looked at the Sustainable Sites credit category, the third at the Location and Transportation credits, the fourth at Water Efficiency, the fifth at the Energy and Atmosphere credits, and the sixth at Materials and Resources.



Indoor Environmental Quality

The quality of the air on the inside of a building is important to all the occupants, as it can contribute to illness and lack of productivity.  Increasing the amount of fresh air and using building materials and products without harmful chemicals can improve the air quality.  Also important is the connection between the occupants and the world outside.  Having access to views of the outside and providing natural lighting are important to occupant well-being.


Minimum Indoor Air Quality Performance

This is a required measure and must be performed in order for a project to be LEED certified.  Provide the required amount of outdoor air ventilation as per ASHRAE Standard 62.1-2010 or local requirement, whichever is more stringent.  Monitor actual outdoor air intake, signaling an alarm when it is +/- 15% of the required minimum.


Environmental Tobacco Smoke Control

This is a required measure and must be performed in order for a project to be LEED certified.  Prohibit smoking inside the building.  Prohibit smoking outside within 25 feet of entrances and exits, air intakes, and operable windows.  Residential projects may allow smoking outside in designated areas, and individual units must be weatherstripped and sealed to prevent smoke from transferring between units or into common areas.


Enhanced Indoor Air Quality Strategies

This credit is worth 1-2 points.  Install permanent entryway systems (mats, grilles, grates) that capture dirt and particulates and keep them from entering the building.  Prevent interior cross-contamination by providing separate air exhaust systems for areas in which potentially harmful chemicals are used (such as a janitor’s closet or copy room).  Air exhaust system must create a negative pressure area (create suction effect).  Outdoor air entry points shall have a filter with a MERV (minimum efficiency reporting value) rating of 13 or higher (measure of the size of particulates that are filtered).  Replace all filters after construction and before occupancy.


Low-Emitting Materials

This credit is worth 1-3 points.  Use materials with low VOC (volatile organic compounds) content.  There are different requirements for interior and exterior products and for different categories of products.  Product categories covered under this credit include: interior paints and coatings, adhesives, flooring, composite wood products, ceilings/walls/