In 2007 the National Association of Home Builders (NAHB) and the International Code Council (ICC) partnered to establish a much-needed and nationally-recognizable standard definition of green building.
The resulting ICC 700 National Green Building Standard™ is the first and only residential green building rating system to undergo the full consensus process and receive approval from the American National Standards Institute (ANSI). The Standard defines green building for single- and multifamily homes, residential remodeling projects, and site development projects while still allowing for the flexibility required for regionally-appropriate best green practices.
Certification to the standard is provided by the NAHB Research Center. Copies of the Standard, a companion commentary, and other publications related to the Standard can be purchased online. A free Green Scoring Tool compatible with the standard is available on the certification side of this website.
For residential buildings, four threshold levels - Bronze, Silver, Gold, and Emerald - allow builders to quantify and qualify green building at all levels. At the Emerald level, the highest rating for a residential green building, a building must incorporate energy savings of 60% or more.
To comply with the Standard, a builder or remodeler must incorporate a minimum number of features in the following areas: lot and site development; energy, water, and resource efficiency; indoor environmental quality; and home owner education. In order to attain a higher level of green certification by the NAHB Research Center, a home must accrue successively higher levels of minimum points in every category – the highest level of certification is dictated by the lowest category score level.
The following tables highlight the point values required in each area for green buildings:
Threshold Point Ratings for Green Buildings
| Green Building Categories |
Performance Point Levels (1) (2) |
| BRONZE |
SILVER |
GOLD |
EMERALD |
| 1. |
Chapter 5 |
Lot Design, Preparation, and Development |
39 |
66 |
93 |
119 |
| 2. |
Chapter 6 |
Resource Efficiency |
45 |
79 |
113 |
146 |
| 3. |
Chapter 7 |
Energy Efficiency |
30 |
60 |
100 |
120 |
| 4. |
Chapter 8 |
Water Efficiency |
14 |
26 |
41 |
60 |
| 5. |
Chapter 9 |
Indoor Environmental Quality |
36 |
65 |
100 |
140 |
| 6. |
Chapter 10 |
Operation, Maintenance, and Building Owner Education |
8 |
10 |
11 |
12 |
| 7. |
|
Additional Points from any category |
50 |
100 |
100 |
100 |
| Total Points |
222 |
406 |
558 |
697 |
| (1) In addition to the threshold number of points in each category, all mandatory provisions of each category shall be implemented. |
| (2) For dwelling units greater than 4,000 square feet (372 square meters), the number of points in Category 7 (Additional Points from any category) shall be increased in accordance with Section 601.1. The "Total Points" shall be increased by the same number of points. |
Additionally, there is a separate rating system that developers can apply to green land developments.
Threshold Point Ratings for Site Design and Development
| Green Subdivision Category |
Performance Point Levels |
| One Star |
Two Stars |
Three Stars |
Four Stars |
| Chapter 4 |
Site Design and Development |
79 |
104 |
134 |
175 |
Many of the mandatory measures found in The ICC 700 National Green Building Standard are consistent with the International Code Council's I-Codes. Additionally, the baseline for energy savings has been updated to IECC 2006. To qualify for "Bronze" in the energy efficiency chapter of the Standard, a home must be at least 15% better than the 2006 IECC.
The Green Scoring Tool allows the scoring of a project to the Standard and includes support materials such as how to verify, intent, how to implement, resources, and Green Approved Products.
As an ANSI-approved standard, the ICC 700 National Green Building Standard is subject to regular reviews and periods of public comment. Proposals for revising the Standard, which will be used as initial input in the next revision cycle, can be submitted by using the online form for submitting proposals.