The ABCs of LEED - Indoor Environmental Quality

Americans spend an average of 80% to 90% of their time indoors, where the level of pollutants can be from two to five times higher than it is outdoors.  By improving indoor air quality we can prevent building related illnesses, reduce absenteeism, improve employee productivity and students’ test scores and shorten hospital stays.

Minimum Indoor Air Quality (IAQ) Performance

High performance buildings are relatively air-tight.  Since there is little or no outside air entering such buildings except by conscious design, it is extremely important to make sure that the ventilation system is working properly.  If there is not enough fresh air from outside passing through a building, the occupants can develop sick building syndrome or building related illness.  So a building that does not meet minimum requirements as defined by ASHRAE 62.1 will not be able to achieve LEED certification.

Environmental Tobacco Smoke Control

For a building to achieve LEED certification, smoking must either be prohibited throughout the building or the spaces in which smoking is permitted must be isolated so that smoke cannot migrate to other areas either naturally or through the heating, ventilation and air conditioning (HVAC) system.

Increased Ventilation and Outdoor Air-Delivery Monitoring

A plentiful supply of fresh air can improve occupant comfort and health.   Installing sensors and measuring devices helps ensure adequate ventilation while maintaining energy efficiency.

Construction IAQ Management Plan – During Construction

Construction management procedures can have a major impact on indoor air quality.  All HVAC equipment should be protected from dust and odors and all ducts should be sealed during construction.  Work areas should be isolated from the rest of the building and job sites should be kept clean.  Porous building materials should be protected from moisture and stored in a clean area.  New, highly efficient filters should be installed in HVAC equipment immediately prior to occupancy.

Construction IAQ Management – Before Occupancy

Even with the best construction management procedures, a certain amount of dust and toxins are often introduced into a newly-built or renovated space.  Air quality can be improved by performing a “flush out” procedure in which the building's ventilation system is used to eliminate contaminants and then air filters are changed again before occupancy.  If the air in a newly-constructed or renovated space can pass certain tests for indoor air quality, a “flush out” may not be necessary.

Low Emitting Materials

Most people are aware that the paint that we have been using for many years contains Volatile Organic Compounds (VOCs) that are potentially irritating or harmful to our health.  LEED criteria include limiting emissions of both VOCs and formaldehyde from a wide variety of sources.  A project can earn points by meeting standards for:

• Low Emitting Materials – Adhesives and Sealants
• Low Emitting Materials – Paints and Coatings
• Low Emitting Materials – Carpet Systems
• Low Emitting Materials – Composite Wood and Laminate Adhesives
• Low Emitting Materials – Systems Furniture and Seating

Indoor Chemical and Pollutant Source Control

LEED encourages isolating sources of potentially hazardous materials, including those from copying, printing, housekeeping and laundry rooms.  LEED guidelines include construction techniques for isolating areas that house these materials   Using only green cleaning products can eliminate the need to isolate housekeeping areas.

Controllability of Systems – Lighting

Most people feel more comfortable if they can control the amount and position of light in their workspaces, so LEED encourages providing individuals with the ability to adjust lighting for their task needs and preferences.  Giving individuals control of their lighting can also save energy and money, since most people are comfortable using less overhead light (which often produces glare on computer screens) and using task lighting only for reading paper.

Controllability of Systems – Temperature and Ventilation

In the typical office building, the operations and maintenance staff regularly deal with complaints from some people who are too hot and others who are too cold.  LEED encourages giving control of the temperature and ventilation of individual spaces to the person(s) who occupy them.

Thermal Comfort – Compliance

Relatively few projects (and very few renovations in existing buildings) will include the installation of systems to allow individual control of temperature and ventilation, because such systems often have relatively long pay-back periods.  But every project can and should result in indoor temperatures that are comfortable for most people.

Thermal Comfort – Monitoring

Designing and building a system to provide comfortable indoor temperatures and adequate ventilation year-round while optimizing energy efficiency is difficult.  Such systems often need to be monitored and adjusted both shortly after installation and on an ongoing basis.  Monitoring can involve either the use of systems that automatically measure temperature and humidity and/or surveys of occupants.

Daylight and Views

People feel more comfortable and cheerful when they have a sense of connection to the outdoors.  So LEED strongly encourages designs that provide as many people as possible with access to daylight and views. LEED points are awarded based upon the percentage of occupants who have access to daylight and views.