Codes and Standards
Review applicable building codes and industry-related standards to determine the minimum levels of compliance for your building. For a green building project, plan to exceed the minimum code requirements. DOE works with states to assist them in adopting the International Code Council's International Energy Conservation Code. Inquire about the status of energy efficiency requirements with your local building code office or visit DOE's Building Energy Codes to learn more about energy efficiency codes in your state or local area.
It is beneficial to follow standards specifically related to building components, such as standards produced by American Society of Heating, Refrigerating, & Air-Conditioning Engineers (ASHRAE), which are useful when developing designs and specifications for space conditioning equipment.
The three ASHRAE Standards that are most often used in building design and operations are Standards 62, 90.1, and 55. There are two methods for complying with the recommendations of these standards, a prescriptive method and a performance method. The prescriptive method means that the designer strictly follows the guidelines laid out in the standard, such as providing a recommended constant level of ventilation air to a space. The performance method means that overall building performance ensures that the intent of the standard is met. For example, a designer using the performance method may specify more or less ventilation air to a space at various times than that recommended in the prescription portion of the standard. Complying with the intent of the standards using the performance method often results in buildings that consume less energy and still maintain healthy and comfortable indoor conditions.
ASHRAE Standard 62-1-2007, "Ventilation for Acceptable Indoor Air Quality." This standard specifies minimum ventilation rates and indoor air quality (IAQ) that will be acceptable to human occupants. Limiting contaminants in indoor air and providing adequate quantity of outdoor air should achieve acceptable IAQ. The standard specifies alternative procedures to obtain acceptable air quality: the ventilation rate procedure and the indoor air quality procedure.
Ventilation rate procedure: Acceptable air quality is achieved by providing ventilation of the specified quantity to the space. For example, 20 CFM/person is required for the AVERAGE (not peak) occupancy in offices.
Indoor air quality procedure: Acceptable air quality is achieved by controlling known contaminants to the space. This procedure incorporates both quantitative and subjective evaluation of contaminants. Indoor carbon dioxide (CO2) levels are often used as an indicator of the concentration of human bioeffluents with this procedure. An indoor-to-outdoor differential concentration not greater than 700 ppm of CO2 indicates that the comfort (odor) criteria related to human bioeffluents are likely to be satisfied.
ASHRAE/IESNA Standard 90.1, "Energy Standard for Buildings Except Low-Rise Residential Buildings." Standard 90.1-2007 is the most recent version. Revisions include considerably more stringent lighting requirements and an alternative method for comparing energy efficiency design strategies.
ASHRAE Standard 55-1992 Addendum-1995, "Thermal Environmental Conditions for Human Occupancy." This standard specifies the combination of indoor space environmental and personal factors that will produce thermal environmental conditions acceptable to 80 percent or more of the occupants within the space.
Other useful standards include the Illuminating Engineering Society's lighting standards.